Advanced UxTheme wrapper

Downloads

• Download demo - 117.0 KB (be sure to have the sample themes installed)
• Download source - 361.1 KB (be sure to have the sample themes installed)
• Sample themes - 1,902.9 KB

Sample application using custom controls (Button, CheckBox, RadioButton, ProgressBar, etc.) drawn with the wrapper.

Introduction

It's been a long time since I became a member of The Code Project. I've learned a lot and it's time for me to share my knowledge.

I think this is not the first time you are reading an article on an uxtheme wrapper. Like me, you have probably done a lot of Googling, seeking information and C# samples about uxtheme (also known as Visual Styles or Windows themes) and found nothing that matches what you want.

However, there are many great articles on The Code Project, like "A Managed C++ Wrapper Around the Windows XP Theme API" by Don Kackman or "Add XP Visual Style Support to OWNERDRAW Controls" by David Zhao and "Themed Windows XP style Explorer Bar" by Mathew Hall, which describe visual styles and provide useful tips. But, in my point of view, they were not designed for a generic C# usage and they don't offer a simple way to use visual styles in our applications.

I wanted to have a way to enumerate and switch between available themes on a computer, so I decided to make my own C# wrapper.

The article

So, how does this work?

I've split this artcile in three parts:

• a quick explanation about uxtheme,
• the visual style format in which you'll find what .theme and .msstyles files hide,
• and the wrapper design in which I'll describe how to use it.

Background needs

Here are the features I wanted to find in a wrapper:

• Windows XP theme support - even on pre XP versions,
• A simple and generic C# wrapper,
• Enumerate available/installed themes on a computer,
• Analyse and decrypt .msstyles files to use them as I want,
• Use a theme's data to switch the look and feel of custom components,
• Provide a way to share a theme's data among custom controls.

Features

What you will find in this sample:

• Theme support even for pre XP versions (normal),
• A "ready to use" C# uxtheme wrapper (with many comments),
• A way to get information about the current used theme,
• A way to enumerate visual styles on your computer,
• A way to get all the information about a visual style,
• A way to save .ini files embedded in .msstyles files,
• A way to save bitmaps embedded in .msstyles files,
• A specific PE file reader which will help you to extract a theme's data,
• Samples of custom controls with their own renderer implementation.

You will also find custom Designers/Editors if you want to learn how to create your own design-time support.

I - Visual Style and UxTheme.dll

    //-----------------------------------------------------------------------
    //  DrawThemeText()     - draws the text using the theme-specified
    //                        color and font for the "iPartId" and
    //                        "iStateId".
    //
    //  hTheme              - theme data handle
    //  hdc                 - HDC to draw into
    //  iPartId             - part number to draw
    //  iStateId            - state number (of the part) to draw
    //  pszText             - actual text to draw
    //  dwCharCount         - number of chars to draw (-1 for all)
    //  dwTextFlags         - same as DrawText() "uFormat" param
    //  dwTextFlags2        - additional drawing options
    //  pRect               - defines the size/location of the part
    //-----------------------------------------------------------------------
    THEMEAPI DrawThemeText(HTHEME hTheme, HDC hdc, int iPartId,
        int iStateId, LPCWSTR pszText, int iCharCount, DWORD dwTextFlags,
        DWORD dwTextFlags2, const RECT *pRect);

    
/// <summary>
    /// Draws text using the color and font defined by the visual style.
    /// </summary>
    /// <param name="hTheme">Handle to a window's specified 
    ///     theme data.</param>
    /// <param name="hdc">Handle to a device context (HDC) used for 
    ///     drawing the theme-defined background image.</param>
    /// <param name="iPartId">Value that specifies the part to draw.</param>
    /// <param name="iStateId">Value that specifies the state of the 
    ///     part to draw.</param>
    /// <param name="pszText">Pointer to a string that contains the text 
    ///     to draw.</param>
    /// <param name="iCharCount">Value that contains the number of 
    ///     characters to draw. If the parameter is set to -1, all 
    ///     the characters in the string are drawn.</param>
    /// <param name="dwTextFlags">A bitwise combination 
    ///     of <see cref="TextFormatFlags"/> values to specify the text 
    ///     formatting.</param>
    /// <param name="dwTextFlags2">Not used. Set to 0.</param>
    /// <param name="pRect">Pointer to a RECT structure that contains 
    ///     the rectangle, in logical coordinates, in which the text 
    ///     is to be drawn.</param>
    [DllImport("UxTheme.dll", CharSet=CharSet.Unicode, SetLastError=true)]
    public static extern System.Int32 DrawThemeText(
        IntPtr hTheme,
        IntPtr hdc,
        UInt32 iPartId,
        UInt32 iStateId,
        String pszText,
        Int32 iCharCount,
        UInt32 dwTextFlags,
        UInt32 dwTextFlags2,
        ref RECT pRect
        );

    //using System.Runtime.InteropServices;
    //using System.ComponentModel;

    //...

    // call an imported function using SetLastError=true before 
    // using this piece of code
    int errorCode = Marshal.GetLastWin32Error();
    Console.WriteLine("The last win32 error code was: "+errorCode);

    // depends on the called function's error codes
    if(errorCode < 0) throw new Win32Exception(errorCode);

II - Visual Style philosophy

    [Theme]

    ; Recycle Bin
    [CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\DefaultIcon]
    full=%SystemRoot%\SYSTEM32\shell32.dll,32
    empty=%SystemRoot%\SYSTEM32\shell32.dll,31

    [Control Panel\Desktop]
    Wallpaper=%WinDir%Resources\Themes\Panther\Wallpaper\Aqua_Blue.jpg
    TileWallpaper=0
    WallpaperStyle=2
    Pattern=
    ScreenSaveActive=0

    [boot]
    SCRNSAVE.EXE=%WinDir%system32\logon.scr

    [VisualStyles]
    Path=%ResourceDir%\Themes\Panther\Panther.msstyles
    ColorStyle=NormalColor
    Size=NormalSize

    [MasterThemeSelector]
    MTSM=DABJDKT
    ThemeColorBPP=4

    System.Collections.IDictionary vars = 
        System.Environment.GetEnvironmentVariables();

    // extract the "Path" value
    System.Text.StringBuilder val = 
        new System.Text.StringBuilder(MAX_PATH); // MAX_PATH = 255
    Kernel32.GetPrivateProfileString(sectionName, keyName, "", val, 
        MAX_PATH, iniFile); // MAX_PATH = 255

    // remove comments
    String path = val.ToString();
    if(path.IndexOf(";") != -1) path = path.Substring(0, 
        result.IndexOf(";"));

    path = path.Replace("%WinDir%", @"%windir%\");
    path = path.Replace(@"\\", @"\");
    path = path.Replace("%ResourceDir%", @"%windir%\Resources");
    path = path.Replace("%windir%", Convert.ToString(vars["windir"]));

    [VisualStyles]
    Path=%ResourceDir%\Themes\Panther\Panther.msstyles
    ColorStyle=NormalColor
    Size=NormalSize    

    [File.Normalpanther]
    ColorSchemes = panther
    Sizes = NormalSize    

III - The wrapper

    // create a new VisualStyleFile
    String themeFile = @"C:\WINDOWS\Resources\Themes\Luna.theme";
    using(VisualStyleFile theme = new VisualStyleFile(themeFile))
    {
        // get the documentation informations
        VisualStyleDocumention doc = theme.Documentation;
        Console.WriteLine(doc.Author + " - " + doc.Copyright);

        // get the color/size scheme
        Console.WriteLine("Color scheme: "+theme.ThemeSchemeName);
        Console.WriteLine("Size scheme: "+theme.ThemeSizeName);

        // get the properties of a component
        VisualStyleProperties buttonProps = theme.GetElementProperties(
            "BUTTON", (uint)ButtonPart.PushButton);
        Console.WriteLine(
            "Button is transparent : "+buttonProps.Transparent);
        Console.WriteLine("Background image: "+buttonProps.ImageFile);

        // etc...
    }

Using the code

I know, it is quite tedious. But the good news are that all you've read is implemented in this sample. I built this part as an FAQ, maybe you'll find what you want to know.

How to enumerate installed theme files

String[] themes = VisualStyleInformation.GetThemeFiles();

foreach(String theme in themes)
{
    Console.WriteLine(theme);
}

How to get a theme information

If you want the current visual style information :

// Documentation properties
Console.WriteLine(
    "Current theme file: "+VisualStyleInformation.CurrentThemeFileName);
Console.WriteLine(
    "Application themed? "+VisualStyleInformation.IsApplicationThemed);
Console.WriteLine("Current theme author: "+VisualStyleInformation.Author);
Console.WriteLine("Current theme company: "+VisualStyleInformation.Company);
// etc...

// Theme raw properties for a "Button"
VisualStyleRenderer renderer = VisualStyleRenderer("BUTTON",
    (uint)ButtonPart.PushButton, (uint)PushButtonState.Normal);
// bool properties
bool isButtonTransparent = renderer.GetBoolean(BooleanProperty.Transparent);
bool isBacgroundFilled = renderer.GetBoolean(BooleanProperty.BackgroundFill);

// Color properties
Color borderColor = renderer.GetColor(ColorProperty.BorderColor);
Color fillColor = renderer.GetColor(ColorProperty.FillColor);
Color textColor = renderer.GetColor(ColorProperty.TextColor);

// String properties
String backgroundImage = GetFilename(FilenameProperty.ImageFile);
String glyph = GetFilename(FilenameProperty.GlyphImageFile);// for combo or
                                                           // caption button

// etc...

If you want the properties for a specific theme (not the current one) :

String themeFile = @"C:\WINDOWS\Resources\Themes\Luna.theme";
using(VisualStyleFile theme = new VisualStyleFile(themeFile))
{
    // get the documentation informations
    VisualStyleDocumention doc = theme.Documentation;
    Console.WriteLine(doc.Author + " - " + doc.Copyright);

    // get the color/size scheme
    Console.WriteLine("Color scheme: "+theme.ThemeSchemeName);
    Console.WriteLine("Size scheme: "+theme.ThemeSizeName);

    // get the properties of a component
    VisualStyleProperties buttonProps = theme.GetElementProperties("BUTTON",
       (uint)ButtonPart.PushButton);
    Console.WriteLine("Button is transparent : "+buttonProps.Transparent);
    Console.WriteLine("Background image: "+buttonProps.ImageFile);

    // etc...
}

Note: Even for the current theme, my preference is the second solution.

How to extract a theme .ini files

// save the .ini files of a specific theme
String themeFile = @"C:\WINDOWS\Resources\Themes\Luna.theme";
String savePath = Environment.CurrentDirectory + @"\inifiles\";
using(VisualStyleFile theme = new VisualStyleFile(themeFile))
{
    theme.SaveIniFiles(savePath);
}

How to get a theme's bitmap

// gets an identified bitmap
String themeFile = @"C:\WINDOWS\Resources\Themes\Luna.theme";
String savePath = Environment.CurrentDirectory;

using(VisualStyleFile theme = new VisualStyleFile(themeFile))
{
    // gets the properties
    VisualStyleProperties buttonProps = theme.GetElementProperties("BUTTON",
        (uint)ButtonPart.PushButton);

    // save the bitmap to disk
    using(Bitmap bmp = theme.GetBitmap(buttonProps.ImageFile))
    {
        bmp.Save(savePath+@"\buttonBitmaps.bmp");
    }
}

How to share a theme among your custom controls

How to use a theme's data (not the current one) with your custom control?

You just have to add a VisualStyleFile to your form via the designer, and update/set its ThemeFile property.

Then, set the VisualStyleFile property of your custom control with the new VisualStyleFile.

How to create your custom renderer

Implementation is up to you : it depends on what you want to paint (eg. a listview header, a button, a scrollbar, a caption, etc.). The tip is to clearly separate the painting behavior from the component logic. My point of view is to create your custom controls as a "bean" which computes the right values (bounds, sizes, etc.) and pass them as parameters to your renderer methods.

Let's have a 15 minutes tutorial : create a renderer for a window's caption button.

1. The first step is to look into the uxtheme's files where you have the window button's list and their possible states : you'll find WindowPart and WindowButtonState enumerations.

The WindowPart contains a lot of values, so the best way to use only the window's button values is to create an enumeration like :

public enum WindowButtonType : int
{
    CloseButton = (int)WindowPart.CloseButton,
    MaxButton = (int)WindowPart.MaxButton,
    MinButton = (int)WindowPart.MinButton,
    HelpButton = (int)WindowPart.HelpButton,
    RestoreButton = (int)WindowPart.RestoreButton,
    SysButton = (int)WindowPart.SysButton
};

2. Create a basic renderer copying one of the sample renderers (RadioButtonRenderer for example), and remove unusefull methods.

/// <summary>
/// Provides methods for drawing a WindowButton control (eg. Help, Close, 
/// Minize, etc.).
/// </summary>
public sealed class WindowButtonRenderer
{
    /// <summary>
    /// Gets a value indicating whether the WindowButtonRenderer class 
    /// can be used to draw a window button control with visual styles.
    /// </summary>
    public static bool IsSupported
    {
        get
        {
            return VisualStyleInformation.IsApplicationThemed;
        }
    }

    private WindowButtonRenderer(){ }

    // ...
}

3. Write in it simple methods that will be called by your component (DrawButton methods) and remember that your renderer will use a Graphics object and will need your component bounds and type.

/// <summary>
/// Provides methods for drawing a WindowButton control (eg. Help, Close, 
/// Minize, etc.).
/// </summary>
public sealed class WindowButtonRenderer
{
    /// <summary>
    /// Gets a value indicating whether the WindowButtonRenderer class 
    /// can be used to draw a window button control with visual styles.
    /// </summary>
    public static bool IsSupported
    {
        get
        {
            return VisualStyleInformation.IsApplicationThemed;
        }
    }

    private WindowButtonRenderer(){ }

    #region Methods

    #region Misc
    /// <summary>
    /// Gets a VisualStyleRenderer for the specified button state.
    /// </summary>
    /// <param name="button">The button type.</param>
    /// <param name="state">The button state.</param>
    private static VisualStyleRenderer GetButtonRenderer(
        WindowButtonType button, WindowButtonState state)
    {
        switch(state)
        {
            case WindowButtonState.Normal:
                if(button == WindowButtonType.CloseButton)        
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.CloseButton.Normal);
                else if(button == WindowButtonType.MaxButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MaxButton.Normal);
                else if(button == WindowButtonType.MinButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MinButton.Normal);
                else if(button == WindowButtonType.HelpButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.HelpButton.Normal);
                else return new VisualStyleRenderer(
                    VisualStyleElement.Window.RestoreButton.Normal);
            case WindowButtonState.Hot:
                if(button == WindowButtonType.CloseButton)        
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.CloseButton.Hot);
                else if(button == WindowButtonType.MaxButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MaxButton.Hot);
                else if(button == WindowButtonType.MinButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MinButton.Hot);
                else if(button == WindowButtonType.HelpButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.HelpButton.Hot);
                else return new VisualStyleRenderer(
                    VisualStyleElement.Window.RestoreButton.Hot);
            case WindowButtonState.Pushed:
                if(button == WindowButtonType.CloseButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.CloseButton.Pressed);
                else if(button == WindowButtonType.MaxButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MaxButton.Pressed);
                else if(button == WindowButtonType.MinButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MinButton.Pressed);
                else if(button == WindowButtonType.HelpButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.HelpButton.Pressed);
                else return new VisualStyleRenderer(
                    VisualStyleElement.Window.RestoreButton.Pressed);
            case WindowButtonState.Disabled:
            default:
                if(button == WindowButtonType.CloseButton)   
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.CloseButton.Disabled);
                else if(button == WindowButtonType.MaxButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MaxButton.Disabled);
                else if(button == WindowButtonType.MinButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MinButton.Disabled);
                else if(button == WindowButtonType.HelpButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.HelpButton.Disabled);
                else return new VisualStyleRenderer(
                    VisualStyleElement.Window.RestoreButton.Disabled);
        }
    }
    /// <summary>
    /// Gets a <see cref="VisualStyleRenderer"> for the specified 
    /// button state.
    /// </summary>
    /// <param name="style">The visual style file to use.</param>
    /// <param name="button">The button type.</param>
    /// <param name="state">The button state.</param>
    private static VisualStyleRenderer GetButtonRenderer(
        VisualStyleFile style, WindowButtonType button, 
        WindowButtonState state)
    {
        if(button == WindowButtonType.CloseButton)        
            return new VisualStyleRenderer(
                VisualStyleElement.Window.CloseButton.GetElement(
                style, state));
        else if(button == WindowButtonType.MaxButton)    
            return new VisualStyleRenderer(
                VisualStyleElement.Window.MaxButton.GetElement(
                style, state));
        else if(button == WindowButtonType.MinButton)    
            return new VisualStyleRenderer(
                VisualStyleElement.Window.MinButton.GetElement(
                style, state));
        else if(button == WindowButtonType.HelpButton)    
            return new VisualStyleRenderer(
                VisualStyleElement.Window.HelpButton.GetElement(
                style, state));
        else return new VisualStyleRenderer(
            VisualStyleElement.Window.RestoreButton.GetElement(
            style, state));
    }
    #endregion

    #region Drawing
    public static void DrawButton(Graphics g, Rectangle bounds, 
        WindowButtonType button, WindowButtonState state)
    {
        if(!IsSupported) throw new InvalidOperationException();

        VisualStyleRenderer renderer = GetButtonRenderer(button, state);
        if(renderer != null) renderer.DrawBackground(g, bounds);
    }

    /// <summary>
    /// Draws a window Close button control in the specified state 
    /// and bounds.
    /// </summary>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ///                     specifies the visual state of the button.</param>
    public static void DrawCloseButton(Graphics g, Rectangle bounds, 
        WindowButtonState state)
    {
        DrawButton(g, bounds, WindowButtonType.CloseButton, state);
    }

    /// <summary>
    /// Draws a window Help button control in the specified state and bounds.
    /// </summary>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    /// specifies the visual state of the button.</param>
    public static void DrawHelpButton(Graphics g, Rectangle bounds, 
        WindowButtonState state)
    {
        DrawButton(g, bounds, WindowButtonType.HelpButton, state);
    }

    /// <summary>
    /// Draws a window Minize button control in the specified state 
    /// and bounds.
    /// </summary>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ///                     specifies the visual state of the button.</param>
    public static void DrawMinizeButton(Graphics g, Rectangle bounds, 
        WindowButtonState state)
    {
        DrawButton(g, bounds, WindowButtonType.MinButton, state);
    }
    /// <summary>
    /// Draws a window Maximize button control in the specified state 
    /// and bounds.
    /// </summary>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ///                     specifies the visual state of the button.</param>
    public static void DrawMaximizeButton(Graphics g, Rectangle bounds, 
        WindowButtonState state)
    {
        DrawButton(g, bounds, WindowButtonType.MaxButton, state);
    }

    /// <summary>
    /// Draws a window Restore button control in the specified state 
    /// and bounds.
    /// </summary>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ///                     specifies the visual state of the button.</param>
    public static void DrawRestoreButton(Graphics g, Rectangle bounds, 
        WindowButtonState state)
    {
        DrawButton(g, bounds, WindowButtonType.RestoreButton, state);
    }
    #endregion
    #endregion
}
</see>

4. Add VisualStyleFile support to your renderer

/// <summary>
/// Provides methods for drawing a WindowButton control (eg. Help, Close, 
/// Minize, etc.).
/// </summary>
public sealed class WindowButtonRenderer
{
    /// <summary>
    /// Gets a value indicating whether the WindowButtonRenderer class 
    /// can be used to draw a window button control with visual styles.
    /// </summary>
    public static bool IsSupported
    {
        get
        {
            return VisualStyleInformation.IsApplicationThemed;
        }
    }

    private WindowButtonRenderer(){ }

    #region Methods

    #region Misc
    /// <summary>
    /// Gets a VisualStyleRenderer for the specified button state.
    /// </summary>
    /// <param name="button">The button type.</param>
    /// <param name="state">The button state.</param>
    private static VisualStyleRenderer GetButtonRenderer(
        WindowButtonType button, WindowButtonState state)
    {
        switch(state)
        {
            case WindowButtonState.Normal:
                if(button == WindowButtonType.CloseButton)        
                    return new VisualStyleRenderer(
                       VisualStyleElement.Window.CloseButton.Normal);
                else if(button == WindowButtonType.MaxButton)    
                    return new VisualStyleRenderer(
                       VisualStyleElement.Window.MaxButton.Normal);
                else if(button == WindowButtonType.MinButton)    
                    return new VisualStyleRenderer(
                       VisualStyleElement.Window.MinButton.Normal);
                else if(button == WindowButtonType.HelpButton)    
                    return new VisualStyleRenderer(
                       VisualStyleElement.Window.HelpButton.Normal);
                else return new VisualStyleRenderer(
                       VisualStyleElement.Window.RestoreButton.Normal);
            case WindowButtonState.Hot:
                if(button == WindowButtonType.CloseButton)
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.CloseButton.Hot);
                else if(button == WindowButtonType.MaxButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MaxButton.Hot);
                else if(button == WindowButtonType.MinButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MinButton.Hot);
                else if(button == WindowButtonType.HelpButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.HelpButton.Hot);
                else return new VisualStyleRenderer(
                    VisualStyleElement.Window.RestoreButton.Hot);
            case WindowButtonState.Pushed:
                if(button == WindowButtonType.CloseButton)        
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.CloseButton.Pressed);
                else if(button == WindowButtonType.MaxButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MaxButton.Pressed);
                else if(button == WindowButtonType.MinButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MinButton.Pressed);
                else if(button == WindowButtonType.HelpButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.HelpButton.Pressed);
                else return new VisualStyleRenderer(
                    VisualStyleElement.Window.RestoreButton.Pressed);
            case WindowButtonState.Disabled:
            default:
                if(button == WindowButtonType.CloseButton)        
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.CloseButton.Disabled);
                else if(button == WindowButtonType.MaxButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MaxButton.Disabled);
                else if(button == WindowButtonType.MinButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.MinButton.Disabled);
                else if(button == WindowButtonType.HelpButton)    
                    return new VisualStyleRenderer(
                        VisualStyleElement.Window.HelpButton.Disabled);
                else return new VisualStyleRenderer(
                    VisualStyleElement.Window.RestoreButton.Disabled);
        }
    }
    /// <summary>
    /// Gets a <see cref="VisualStyleRenderer"> for the specified 
    /// button state.
    /// </summary>
    /// <param name="style">The visual style file to use.</param>
    /// <param name="button">The button type.</param>
    /// <param name="state">The button state.</param>
    private static VisualStyleRenderer GetButtonRenderer(
        VisualStyleFile style, WindowButtonType button, 
        WindowButtonState state)
    {
        if(button == WindowButtonType.CloseButton)        
            return new VisualStyleRenderer(
                VisualStyleElement.Window.CloseButton.GetElement(
                style, state));
        else if(button == WindowButtonType.MaxButton)    
            return new VisualStyleRenderer(
                VisualStyleElement.Window.MaxButton.GetElement(
                style, state));
        else if(button == WindowButtonType.MinButton)    
            return new VisualStyleRenderer(
                VisualStyleElement.Window.MinButton.GetElement(style,state));
        else if(button == WindowButtonType.HelpButton)    
             return new VisualStyleRenderer(
               VisualStyleElement.Window.HelpButton.GetElement(style,state));
        else return new VisualStyleRenderer(
            VisualStyleElement.Window.RestoreButton.GetElement(style,state));
    }
    #endregion

    #region Drawing
    public static void DrawButton(Graphics g, Rectangle bounds, 
        WindowButtonType button, WindowButtonState state)
    {
        if(!IsSupported) throw new InvalidOperationException();

        VisualStyleRenderer renderer = GetButtonRenderer(button, state);
        if(renderer != null) renderer.DrawBackground(g, bounds);
    }

    public static void DrawButton(VisualStyleFile style, Graphics g, 
        Rectangle bounds, WindowButtonType button, WindowButtonState state)
    {
        if(!IsSupported) throw new InvalidOperationException();

        VisualStyleRenderer renderer = GetButtonRenderer(style, button, 
            state);
        if(renderer != null) renderer.DrawBackground(g, bounds);
    }

    /// <summary>
    /// Draws a window Close button control in the specified state 
    /// and bounds.
    /// </summary>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ///                     specifies the visual state of the button.</param>
    public static void DrawCloseButton(Graphics g, Rectangle bounds, 
        WindowButtonState state)
    {
        DrawButton(g, bounds, WindowButtonType.CloseButton, state);
    }
    /// <summary>
    /// Draws a window Close button control in the specified state 
    /// and bounds.
    /// </summary>
    /// <param name="style">The visual style file to use.</param>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ////                    specifies the visual state of the button.</param>
    public static void DrawCloseButton(VisualStyleFile style, Graphics g, 
        Rectangle bounds, WindowButtonState state)
    {
        DrawButton(style, g, bounds, WindowButtonType.CloseButton, state);
    }


    /// <summary>
    /// Draws a window Help button control in the specified state and bounds.
    /// </summary>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ///                     specifies the visual state of the button.</param>
    public static void DrawHelpButton(Graphics g, Rectangle bounds, 
        WindowButtonState state)
    {
        DrawButton(g, bounds, WindowButtonType.HelpButton, state);
    }
    /// <summary>
    /// Draws a window Help button control in the specified state and bounds.
    /// </summary>
    /// <param name="style">The visual style file to use.</param>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ///                     specifies the visual state of the button.</param>
    public static void DrawHelpButton(VisualStyleFile style, Graphics g, 
        Rectangle bounds, WindowButtonState state)
    {
        DrawButton(style, g, bounds, WindowButtonType.HelpButton, state);
    }


    /// <summary>
    /// Draws a window Minize button control in the specified 
    /// state and bounds.
    /// </summary>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ///                     specifies the visual state of the button.</param>
    public static void DrawMinizeButton(Graphics g, Rectangle bounds, 
        WindowButtonState state)
    {
        DrawButton(g, bounds, WindowButtonType.MinButton, state);
    }
    /// <summary>
    /// Draws a window Minize button control in the specified state 
    /// and bounds.
    /// </summary>
    /// <param name="style">The visual style file to use.</param>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ///                     specifies the visual state of the button.</param>
    public static void DrawMinizeButton(VisualStyleFile style, Graphics g, 
        Rectangle bounds, WindowButtonState state)
    {
        DrawButton(style, g, bounds, WindowButtonType.MinButton, state);
    }


    /// <summary>
    /// Draws a window Maximize button control in the specified state 
    /// and bounds.
    /// </summary>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ///                     specifies the visual state of the button.</param>
    public static void DrawMaximizeButton(Graphics g, Rectangle bounds, 
        WindowButtonState state)
    {
        DrawButton(g, bounds, WindowButtonType.MaxButton, state);
    }
    /// <summary>
    /// Draws a window Maximize button control in the specified state and 
    /// bounds.
    /// </summary>
    /// <param name="style">The visual style file to use.</param>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ///                     specifies the visual state of the button.</param>
    public static void DrawMaximizeButton(VisualStyleFile style, Graphics g, 
        Rectangle bounds, WindowButtonState state)
    {
        DrawButton(style, g, bounds, WindowButtonType.MaxButton, state);
    }

    /// <summary>
    /// Draws a window Restore button control in the specified 
    /// state and bounds.
    /// </summary>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ///                     specifies the visual state of the button.</param>
    public static void DrawRestoreButton(Graphics g, Rectangle bounds, 
        WindowButtonState state)
    {
        DrawButton(g, bounds, WindowButtonType.RestoreButton, state);
    }
    /// <summary>
    /// Draws a window Restore button control in the specified 
    //// state and bounds.
    /// </summary>
    /// <param name="style">The visual style file to use.</param>
    /// <param name="g">The Graphics used to draw the button.</param>
    /// <param name="bounds">The button bounds.</param>
    /// <param name="state">One of the WindowButtonState values that 
    ///                     specifies the visual state of the button.</param>
    public static void DrawRestoreButton(VisualStyleFile style, Graphics g, 
        Rectangle bounds, WindowButtonState state)
    {
        DrawButton(style, g, bounds, WindowButtonType.RestoreButton, state);
    }
    #endregion
    #endregion
}
</see>

5. Create your WindowButton component, just like the renderer (copy the CustomRadioButton component for example, and remove unusefull fields and methods).
   6 - After cleaning, add your fields like WindowButtonState and WindowButtonType and change the renderer in the OnPaint() event with your brand new WindowButtonRenderer.
   7 - Add your own component behavior and, in the end, you will have something like the sample code below :

public class WindowButton : System.Windows.Forms.Control, 
    IVisualStyleSwitchable
{
    /// <summary>Event fired when a control's property changes.</summary>
    [Category("Action"), Description(
        "Occurs when a control's property changes."),]
    public event EventHandler PropertyChanged = null;

    #region Fields
    private System.ComponentModel.IContainer components = null;

    private WindowButtonType type = WindowButtonType.CloseButton;
    private WindowButtonState state = WindowButtonState.Normal;
    private Color backColor;
    private Rectangle realBounds = Rectangle.Empty;
    private Size realSize = Size.Empty;
    private VisualStyleFile file = null;

    #endregion

    #region Accessors

    #region Runtime
    /// <summary>
    /// Gets or sets the button state.
    /// </summary>
    private WindowButtonState State
    {
        get
        {
            return this.state;
        }
        set
        {
            if(this.state == value) return;
            this.state = value;

            OnPropertyChanged();
        }
    }
    /// <summary>
    /// Get the control real size.
    /// </summary>
    [Browsable(false),]
    [DesignerSerializationVisibility(
        DesignerSerializationVisibility.Hidden),]
    private Size RealSize
    {
        get
        {
            if(this.realSize==Size.Empty) realSize = Size;
            return this.realSize;
        }
        set
        {
            this.realSize = value;
        }
    }
    /// <summary>
    /// Get the control bound's rectangle.
    /// </summary>
    [Browsable(false),]
    [DesignerSerializationVisibility(
        DesignerSerializationVisibility.Hidden),]
    public new Rectangle ClientRectangle
    {
        get
        {
            if(this.realBounds.Width != RealSize.Width || 
                this.realBounds.Height != RealSize.Height)
            {
                this.realBounds = new Rectangle(0, 0, RealSize.Width, 
                    RealSize.Height);
            }

            return this.realBounds;
        }
    }
    #endregion

    #region Appearance
    /// <summary>
    /// Gets or sets the visual style to use.
    /// </summary>
    [Browsable(true), Category("Appearance"),]
    [DefaultValue(null),]
    public Devcorp.Controls.VisualStyles.VisualStyleFile VisualStyle
    {
        get
        {
            return this.file;
        }
        set
        {
            if(this.file == value) return;

            if(this.file != null) this.file.ThemeFileChanged -= 
                new EventHandler(file_ThemeFileChanged);
            this.file = value;
            if(this.file != null) this.file.ThemeFileChanged += 
                new EventHandler(file_ThemeFileChanged);

            OnPropertyChanged();
        }
    }
    /// <summary>
    /// Gets or sets the visual style to use.
    /// </summary>
    [Browsable(true), Category("Appearance"),]
    [DefaultValue(typeof(WindowButtonType),"CloseButton"),]
    public WindowButtonType Type
    {
        get
        {
            return this.type;
        }
        set
        {
            if(this.type == value) return;
            this.type = value;

            OnPropertyChanged();
        }
    }

    /// <summary>
    /// Gets or sets the background color.
    /// </summary>
    [Browsable(true), Category("Appearance"),]
    [DefaultValue(typeof(Color), "Control"),]
    public new Color BackColor
    {
        get
        {
            return this.backColor;
        }
        set
        {
            if(this.backColor == value) return;

            this.backColor = value;
            base.BackColor = value;

            OnPropertyChanged();
        }
    }

    #endregion
    #endregion

    #region Constructor(s)
    /// <summary>
    /// Default constructor.
    /// </summary>
    public WindowButton()
    {
        SetStyle(ControlStyles.UserPaint, true);
        SetStyle(ControlStyles.AllPaintingInWmPaint, true);
        SetStyle(ControlStyles.DoubleBuffer, true);
        SetStyle(ControlStyles.ResizeRedraw, true);
        SetStyle(ControlStyles.SupportsTransparentBackColor, true);
        SetStyle(ControlStyles.Selectable, true);

        InitializeComponent();
    }
    /// <summary>
    /// Default constructor.
    /// </summary>
    public WindowButton(System.ComponentModel.IContainer container) : this()
    {
        container.Add(this);
    }

    #endregion
    #region Methods

    #region VS generated code
    /// <summary>Clean up any resources being used.</summary>
    protected override void Dispose( bool disposing )
    {
        if( disposing )
        {
            if (components != null)
            {
                components.Dispose();
            }
        }
        base.Dispose( disposing );
    }

    /// <summary>
    /// Required method for Designer support - do not modify
    /// the contents of this method with the code editor.
    /// </summary>
    private void InitializeComponent()
    {
        //
        // WindowButton
        //
        this.Size = new System.Drawing.Size(20, 20);

    }

    #endregion
    #region Drawing
    /// <summary>
    /// Handles Onpaint event.
    /// </summary>
    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);

        if(!Disposing && !Parent.Disposing)
        {
            if(this.file != null && this.file.StyleFile!=String.Empty)
            {
                WindowButtonRenderer.DrawButton(this.file, e.Graphics, 
                   ClientRectangle, this.type, this.state);
            }
            else
            {
                WindowButtonRenderer.DrawButton(e.Graphics, 
                    ClientRectangle, this.type, this.state);
            }
        }
    }

    #endregion

    #region Events
    private void file_ThemeFileChanged(object sender, EventArgs e)
    {
        Invalidate();
    }
    /// <summary>
    /// Fires the PropertyChange event.
    /// </summary>
    protected virtual void OnPropertyChanged()
    {
        if(PropertyChanged!=null) PropertyChanged(this, EventArgs.Empty);

        Invalidate();
    }
    /// <summary>
    /// Handles WM messages to set the right button states.
    /// </summary>
    /// <param name="m"></param>
    protected override void WndProc(ref Message m)
    {
        base.WndProc(ref m);

        if(m.HWnd == Handle)
        {
            switch(m.Msg)
            {
                case (int)Messages.WM_NCCALCSIZE:
                    if(m.WParam==IntPtr.Zero || m.WParam==new IntPtr(1))
                    {
                        NCCALCSIZE_PARAMS csp = (
                            NCCALCSIZE_PARAMS)Marshal.PtrToStructure(
                            m.LParam, typeof(NCCALCSIZE_PARAMS));

                      RealSize = new Size((csp.rgrc1.Right-csp.rgrc1.Left),
                            (csp.rgrc1.Bottom-csp.rgrc1.Top));
                        Marshal.StructureToPtr(csp, m.LParam, false );
                    }
                    break;
                case (int) Messages.WM_CREATE:
                    this.state = (Enabled)? WindowButtonState.Normal: 
                        WindowButtonState.Disabled;
                    break;
                case (int)Messages.WM_LBUTTONDBLCLK:
                case (int)Messages.WM_LBUTTONDOWN:
                    if(Enabled)
                    {
                        if(!Focused) Focus();
                        State = WindowButtonState.Pushed;
                    }
                    break;
                case (int)Messages.WM_LBUTTONUP:
                    if(Enabled)
                    {
                        State = WindowButtonState.Hot;
                    }
                    break;
                case (int)Messages.WM_MOUSEHOVER:
                case (int)Messages.WM_MOUSEMOVE:
                    if(Enabled)
                    {
                        if(this.state != WindowButtonState.Pushed) State = 
                            WindowButtonState.Hot;
                    }
                    break;
                case (int)Messages.WM_MOUSELEAVE:
                case (int)Messages.WM_KILLFOCUS:
                    if(Enabled)
                    {
                        State = WindowButtonState.Normal;
                    }
                    break;
                case (int)Messages.WM_SETFOCUS:
                case (int)Messages.WM_ENABLE:
                    if(Enabled)
                    {
                        State = WindowButtonState.Normal;
                    }
                    else
                    {
                        State = WindowButtonState.Disabled;
                    }
                    break;
            }
        }
    }
    #endregion
    #endregion
}

Omedeto! Your custom WindowButton is ready to use! (Hoops! You should add it on your form before)

Note: I've included four more renderers in the sample (a ButtonRenderer, a CheckboxRenderer, a RadioButtonRenderer and a ProgressBarRenderer). You can use them to create your own renderers (or ask me if I've already implement what you need).

Known issues

• I've not created a renderer for all the visual style parts, so you can find bugs (or a lack of function support) during your own implementation.
• Using current active theme data in a VisualStyleFile can cause your application to crash : don't associate this kind of VisualStyleFile to your custom controls.
• Using too much VisualStyleFiles in your project will cause your form(s) to flicker when loading (I'm working on a way to throw an event when all of a theme's data would have been populated)
• Using too much VisualStyleFiles in your project will cause a high memory usage (because we are in a managed environment of course)
• Renderer implementation is quite annoying : you should copy/modify the sample renderers to make your own.

If you find a bug or an incoherence, don't be afraid to tell me. I'll fix it and update this article.

Points of Interest

Maybe the first interesting point is the wrapper itself. The more complicated part is bitmap drawing and stretch operations. You can look at the DrawBackground() methods in the VisualStyleRenderer class and StretchBitmap() methods in VisualStyleHelper class.

Implementing a PE file reader is quite a hard task. I you want to build your own PE file reader, you can read the PECOFF format specification, or you can use/extend the PEFile class of the sample. Another idea, you can extend the PEFile class to create a resource editor like ResEdit.

While I was doing a lot a refactoring and performance tests, I've implemented a fast .ini file memory mapper. The aim target was to avoid working with backep-up files (the .ini embedded in the .msstyles) which involved a lot of I/O (and to use win32 Kernel functions). You will find it as the MemoryIniFile and MemoryIniSection classes.

Another interesting thing is the wrapper design. For those who are still using .NET 1.1 and are going to use .NET 2.0 (or 3.0), it will be quite easy because they will find exactly the same classes (but with less possibilities). Converting their projects will be as simple as rename references to the namespace "Devcorp.Controls.VisualStyles" to "System.Windows.Forms.VisualStyles" and copy missing classes.

History

• 13 May 2007 - Version 0.85
  • Remove MemoryIniHelper (redundant duplicated methods).
  • Added filled background (non bitmap) support in VisualStyleRenderer.DrawBackground().
  • Added full visual style property inheritance (see VisualStyleProperties).
  • Added GroupBoxRenderer.
  • Added ComboBoxRenderer.
  • Added TextBoxRenderer.
  • Some bug fixes and few optimizations.
• 9 May 2007 - just corrections of the article (orthography)
• 6 May 2007 - Version 0.82
  • Fixed lost 1px width/height when drawing stretched bitmaps.
  • Fixed VisualStyleFile support in GetBackgroundContentRectangle() method.
  • Added partial VisualStyleFile support in DrawEdge() method.
  • Added ExplorerBarRenderer renderer (and its sample).
  • Added IEBarRenderer renderer (and its sample).
  • Some bug fixes.
• 01 May 2007 - Version 0.81
  • Fixed parsing error in MemoryIniFile : some lines with key/value and a comment were not computed.
  • Fixed drawing incoherence for components with a glyph.
  • Fixed high memory usage when using more than three VisualStyleFile.
  • Added real support of theme's sizing rules.
  • Added WindowButton and WindowButtonRenderer in the sample.
  • Some bug fixes.
• 29 April 2007 - Version 0.8 (posted on The Code Project)
  • Added .ini file memory mapper.
  • Added embedded theme's .ini files save support.
  • Added stand-alone renderers as samples.
  • Lot of design refactoring and optimization.
  • Some bug fixes.
• 20 November 2005 - Initial project release.