help? - C# Discussion Boards

Dragging files onto a windows form

22-Sep-02 20:15

Passing 0 as last parameter value (dwThreadId) complicates a bit things. MSDN says that in this case, the hook procedure must reside in a DLL. See for yourself what's said about lpfn :

lpfn
[in] Pointer to the hook procedure. If the dwThreadId parameter is zero or specifies the identifier of a thread created by a different process, the lpfn parameter must point to a hook procedure in a dynamic-link library (DLL). Otherwise, lpfn can point to a hook procedure in the code associated with the current process.
hMod
[in] Handle to the DLL containing the hook procedure pointed to by the lpfn parameter. The hMod parameter must be set to NULL if the dwThreadId parameter specifies a thread created by the current process and if the hook procedure is within the code associated with the current process.
dwThreadId
[in] Specifies the identifier of the thread with which the hook procedure is to be associated. If this parameter is zero, the hook procedure is associated with all existing threads running in the same desktop as the calling thread.

MS quote (http://www.microsoft.com/ddk) : As of September 30, 2002, the Microsoft® Windows® 2000 DDK, the Microsoft Windows 98 DDK, and the Microsoft Windows NT® 4.0 DDK will no longer be available for purchase or download on this site.

Desktop Hierarchy

Wjousts22-Sep-02 13:41

Wjousts

22-Sep-02 13:41

I'm trying to create a treeview that is populated with the directory structure of the computer (like the left hand window of explorer). I can use System.IO.Directory or System.IO.DirectoryInfo to extract subdirectories for a given root (e.g. C:\) and add them to my tree, but ideally I'd like to start at Desktop and include My Computer (and then A:\,C:\,D:\,etc) just like explorer does. Does the .NET framework have any classes that allow you to move through that hierarchy, i.e. return everything listed under Desktop and then everything under My Computer, etc?
Thanks

Re: Desktop Hierarchy

Paul Riley22-Sep-02 15:07

Paul Riley

22-Sep-02 15:07

Check out Environment.GetFolderPath(Environment.SpecialFolder.DesktopFolder).

Paul

help?

imran_rafique22-Sep-02 13:35

imran_rafique

22-Sep-02 13:35

please read that code and solve my problem.
Given after that code.
///////////////////////////////////////////////////////////
>>><<<><

public class Win32Hook  {       [DllImport("kernel32")]       public static extern int GetCurrentThreadId();        [DllImport( "user32", CharSet=CharSet.Auto,CallingConvention=CallingConvention.StdCall)]       public static extern int SetWindowsHookEx( HookType idHook,                      HOOKPROC lpfn,                      int hmod,                      int dwThreadId                      );        public enum HookType       {            WH_KEYBOARD = 2       }       public delegate int HOOKPROC(int nCode, int wParam, int lParam);        private HOOKPROC hookProc; //private field with class scope        public void SetHook()       {             // set the keyboard hook            hookProc = new HOOKPROC(this.MyKeyboardProc);             SetWindowsHookEx(HookType.WH_KEYBOARD, hookProc, 0,                    GetCurrentThreadId());        }        public int MyKeyboardProc(int nCode, int wParam, int lParam)       {  	  //line of code           return 0;       }  }

zimbar22-Sep-02 5:01

zimbar

22-Sep-02 5:01

I'm trying to implement a drag and drop between the windows shell and a windows form but although I implement the drag event nothing happens, when I drag a file. I also cannot find any examples on the topic.

Any ideas?

Re: Dragging files onto a windows form

Stephane Rodriguez.22-Sep-02 5:20

22-Sep-02 5:20

You may look this implementation[^].

Custom Control

Donald Blachly21-Sep-02 18:55

Donald Blachly

21-Sep-02 18:55

I am building a custom control in C# out of existing controls. One question I have:

Normally, when a control such as a TextBox is added to a Form, it is declared as private but as a member of the form, the Textbox.Text for example, is acessible for coding in the form. With a custom control, if I declare the controls as private, they are not directly accessible to the form the control is placed on. Should I declare the individual controls as protected or public members in the custom control and the custom control as private? Will this protect the data members or is the another way that would be better?

When you come to a fork in the road, take it! Y. Berra

Stephane Rodriguez.21-Sep-02 21:24

21-Sep-02 21:24

Adding set/get properties in your custom control allows to inoculate the public interface from the actual custom control implementation. Hence lower code maintenance for instance when a TextBox becomes a MyTextBoxEx.

Of course, no one needs to care that much about object-oriented programming, and the controls could be declared as public. This would btw shorten development time. And there is no need to feel the same for it, especially when things are obvious.

Unfortunately, there is no known option (or I don't know) to tell the VS.NET IDE to add controls as public, instead of private.

My -0.5 cent

James T. Johnson21-Sep-02 21:42

21-Sep-02 21:42

StephaneRodriguez wrote:
Unfortunately, there is no known option (or I don't know) to tell the VS.NET IDE to add controls as public, instead of private.

In the properties window there is a property called Modifiers in the Design category; that will let you set the class visibility for the control.

James
"And we are all men; apart from the females." - Colin Davies

Stephane Rodriguez.21-Sep-02 22:59

21-Sep-02 22:59

The Modifiers property applies to an existing control, and on a one-by-one basis. Of course, I admit there is a challenge here for those willing to write the code automating this to the whole set of child controls.(can't figure out by the way why there is no Modifiers property at the Form level, this would have been a nice place for all controls added later).

James T. Johnson21-Sep-02 23:13

21-Sep-02 23:13

StephaneRodriguez wrote:
The Modifiers property applies to an existing control, and on a one-by-one basis

In most cases you can select multiple controls and set the Modifiers property for all of them.

So far the only time I've found that you can't is when the control you are selecting comes from the base class. That makes sense because the forms designer uses the compiled assembly to do its work, so it obviously can't modify the visibility of the variable in the assembly.

StephaneRodriguez wrote:
can't figure out by the way why there is no Modifiers property at the Form level, this would have been a nice place for all controls added later).

This would be a nice addition for those that would like to expose all controls easily. Smile | :)

James
"And we are all men; apart from the females." - Colin Davies

Centering a window at runtime?

Donald Blachly22-Sep-02 3:47

Donald Blachly

22-Sep-02 3:47

Thanks for all your comments and especially your perspective on OOP. I know there can be valid reasons to limit access but it seemed overkill to write a get/set and set the value to anything the user wants to anyway! I shall try to judiciously use public members.

don

When you come to a fork in the road, take it! Y. Berra

Zinj21-Sep-02 14:00

Zinj

21-Sep-02 14:00

I cannot figure out if there are any methods to get the windows resolution in .NET at run time?
Acutally I have a window that resizes according to the data and I want it to center itself on the screen.
Any idea how to do it with pure .NET?
Thank you

David Stone21-Sep-02 14:14

David Stone

21-Sep-02 14:14

Try this in your constructor:

this.StartPosition = FormStartPosition.CenterScreen;

Smile | :)

Last week I stated that this woman was the ugliest woman I had ever seen. I have since been visited by her sister and now wish to withdraw that statement.
-Mark Twain

James T. Johnson21-Sep-02 14:30

21-Sep-02 14:30

If setting the StartPosition property doesn't work, you can get the screen resolution by using the Screen class.

Screen screenRect = Screen.GetWorkingArea(this);
 
this.Location = new Point(
  (( screenRect.Width - this.Width ) / 2) + screenRect.Left,
  (( screenRect.Height - this.Height ) / 2) + screenRect.Top
);

The reason I add screenRect.Left and screenRect.Top is because in a multi-monitor situation the top-left corner of the screen might not be (0, 0).

Untested code, but that *should* work Wink | ;)

James
"And we are all men; apart from the females." - Colin Davies

Zinj21-Sep-02 15:43

Zinj

21-Sep-02 15:43

This one really looks great. I'm goint to try it as soon as I return to my development os. I suppose screen is a .net class. I haven't noticed it - too many classes, too much to learn Wink | ;)

Thank you!

James T. Johnson21-Sep-02 15:50

21-Sep-02 15:50

Zinj wrote:
I suppose screen is a .net class.

Yes, I forgot to mention that, the full name is System.Windows.Forms.Screen

James
"And we are all men; apart from the females." - Colin Davies

Zinj22-Sep-02 4:51

Zinj

22-Sep-02 4:51

and I think I have used Rectangle for the declaration

RGB and HSV

Tomas Petricek21-Sep-02 4:43

Tomas Petricek

21-Sep-02 4:43

Hello,

Does anybody know how can I convert color in HSB format to RGB ??
(from RGB ro HSB I can use Color class)

<br />
Color cl=Color.FromArgb(64,128,162);<br />
float h=cl.GetHue();<br />
float s=cl.GetSaturation();<br />
float b=cl.GetBrightness();<br />

But Color hasn't got any SetHue, SetSaturation or SetBrightness method Frown | :(

Thank you

Re: RGB and HSV

leppie21-Sep-02 5:34

leppie

21-Sep-02 5:34

Hi
Someone post a method a few months back in this forum, do a search for HSB, you should find it easily.

Smile | :)

Give them a chance! Do it for the kittens, dear God, the kittens!

Re: RGB and HSV

Stephane Rodriguez.21-Sep-02 5:42