Re: While MouseDown - C# Discussion Boards

17-Oct-09 10:31

SystemBiosDate key doesn't exist

only two letters away from being an asset

Re: getting biosdate

Luc Pattyn17-Oct-09 12:17

17-Oct-09 12:17

My Vista system's registry has such a SystemBiosDate entry, type REG_SZ, value 04/21/08, which for sure isn't the current date, however it could be the date the manufacturer (Dell) assembled and loaded my machine.

Smile | :)

Luc Pattyn

I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

Local announcement (Antwerp region): Lange Wapper? Neen!

Re: getting biosdate

Not Active17-Oct-09 16:21

17-Oct-09 16:21

Probably manufacturer specific. My Windows 7, nor Server 208 boxes doesn't have it.

only two letters away from being an asset

While MouseDown

Zap-Man17-Oct-09 3:27

17-Oct-09 3:27

I am trying to do some events while the mouse button is down.
Here is what I have

private static bool IsKeyDown = false;

private void button1_MouseDown(object sender, MouseEventArgs e) {
IsKeyDown = true;
while (IsKeyDown) {
Winamp.Winamp.VolumeDown();

}

}

private void button1_MouseUp(object sender, MouseEventArgs e) {

IsKeyDown = false;

}

The problem is when it hits the mouse down event It continues to run the while loop and does not hit the mouse up event.

I don't want to use a timer to do this.

I did see some code that I think will work better in my app but I cant seem to get it to work can some one please help.

http://stackoverflow.com/questions/1152525/c-winform-looping-event-on-press-button[^]

private bool mouseDown = false;

private void buttonScrollUp_MouseDown(object sender, MouseEventArgs e)
{
mouseDown = true;
new Thread(() => {
while (mouseDown)
{
Invoke(new MethodInvoker(() => [DO_THE_SCROLLING_HERE));
Thread.Sleep([SET_AUTOREPEAT_TIMEOUT_HERE);
}
})
.Start();
}

private void buttonScrollUp_MouseUp(object sender, MouseEventArgs e)
{
mouseDown = false;
}

Lyon Sun17-Oct-09 4:00

Lyon Sun

17-Oct-09 4:00

Zap-Man wrote:
private static bool IsKeyDown = false;

Confused. Can this variable be changed ever? Correct me if I am wrong... Smile | :)

Zap-Man17-Oct-09 4:09

17-Oct-09 4:09

yes it changes on the mouse down to true. but the mouse up event never fires because the loop has not finished. but it will change in the mouse up event. if the value never changed then I would have to set it to const or read only. A static variable will change. private means this variable is not accessible from another class. when the form is initialized the variable is set to false. When the mouseDown event is fired then the variable is set to true. This is working. the problem lies in the loop. Because it is in the loop the MouseUp event never executes.

Richard MacCutchan17-Oct-09 4:44

Richard MacCutchan

17-Oct-09 4:44

Zap-Man wrote:
IsKeyDown = true;
while (IsKeyDown) {
Winamp.Winamp.VolumeDown();
}

This loop will never terminate so your event handler button1_MouseDown will never notify the framework that it is complete. This blocks your application from doing anything else, so you need to separate the functions somehow.

BTW it helps if you put <pre></pre> tags around your code snippet so it is easier to read.

Luc Pattyn17-Oct-09 5:08

17-Oct-09 5:08

Hi,

this is all wrong.

1. event handlers get executed on the main thread (aka GUI thread), hence MouseUp cannot do anything as long as MouseDown is active.

2. Your while loop will never exit.

3. Your while loop has no delay, so at what rate will VolumeDown be called?

4. Using Thread.Sleep would not be a good approach as that blocks the GUI; using a timer (a Windows.Forms.Timer) is the perfect solution: start the timer on MouseDown, stop it on MouseUp (or better yet have the Tick handler check Control.MouseButtons).

Zap-Man wrote:
I don't want to use a timer

why? because you don't understand them? because you don't like a clean and natural solution?

Smile | :)

Luc Pattyn

I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

Local announcement (Antwerp region): Lange Wapper? Neen!

Zap-Man17-Oct-09 5:43

17-Oct-09 5:43

Look I am not looking for Critics. If you cant help then don't bother posting. I understand timers perfectly. My app has a timer which runs a massive about of code. I understand what the program is doing. I am looking for a way around it.

Not Active17-Oct-09 6:17

17-Oct-09 6:17

This response is uncalled for, Luc's comments are valid.

only two letters away from being an asset

Not Active17-Oct-09 5:42

17-Oct-09 5:42

private AutoResetEvent autoEvent = null;
private void OnMouseDown(object sender, MouseEventArgs e)
{
autoEvent = new AutoResetEvent(false);
ThreadPool.QueueUserWorkItem(VolumeDown);
}

private void OnMouseUp(object sender, MouseEventArgs e)
{
autoEvent.Set();
}

private void VolumeDown(object state)
{
bool lowerVolume = true;
do
{
BeginInvoke(new MethodInvoker(delegate() { Winamp.Winamp.VolumeDown(); }), null);
if(autoEvent.WaitOne(100))
lowerVolume = false;
}
while(lowerVolume);
}

only two letters away from being an asset

Zap-Man17-Oct-09 5:46

17-Oct-09 5:46

Thank you Mark This is excatly what Im looking for. Congrats to you!!! Thumbs Up | :thumbsup:

Not Active17-Oct-09 6:15

17-Oct-09 6:15

You're welcome

only two letters away from being an asset

Owner drawn TabControl doesn't act as I want it

dojohansen18-Oct-09 0:49

dojohansen

18-Oct-09 0:49

First, the reason your original idea doesn't work is that the event handlers are all on the same thread. The mouseup handler cannot run until mousedown returns, and mousedown doesn't return until mouseup has run, so you're basically deadlocking yourself with only one thread! Big Grin | :-D

Depending on what you do in those handlers you may be able to do it in another thread instead. But if you want to do anything to the GUI itself, you aren't allowed to do so on any thread but the "gui thread", which is the same thread that is raising the events.

So you have to use another hook... to marshal the call back to the UI thread again!

Here's an example of how to do this. To run it, create a new windows forms application and replace Form1.cs with:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        long n;
        MouseButtons buttons;
        Label label1;

        public Form1()
        {
            label1 = new Label();
            label1.Text = "here";
            Controls.Add(label1);
            label1.MouseUp += new MouseEventHandler(label1_MouseUp);
            label1.MouseDown += new MouseEventHandler(label1_MouseDown);
        }


        void label1_MouseDown(object sender, MouseEventArgs e)
        {
            buttons = e.Button;
            new Thread(run).Start();
        }

        void label1_MouseUp(object sender, MouseEventArgs e)
        {
            buttons = MouseButtons.None;
        }

        void run()
        {
            var upd = new Action(update);
            while (buttons != MouseButtons.None) label1.Invoke(upd);
        }

        void update()
        {
            n = (buttons == MouseButtons.Left ? --n : ++n);
            label1.Text = n.ToString();
        }
    }
}

WebMaster17-Oct-09 0:20

WebMaster

17-Oct-09 0:20

Hey guys.

So, my owner drawn TabControl, inheriting from the TabControl in System.Windows.Forms, doesn't want to give me a transparent background. (Or I simply don't know how) It's also giving me these weird gaps, and somehow it's not filling out all the space in my Panel parent.

Here's a screenshot: http://tinypic.com/r/1tou9h/4

using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Design;
using System.IO;
using System.Linq;
using System.Runtime;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;

using Storm;
using Storm.Docking;
using Storm.Docking.Controls;
using Storm.Docking.Visual;
using Storm.Docking.Visual.Drawing;
using Storm.Docking.Visual.Glyphs;
using Storm.Docking.Win32;

namespace Storm.Docking.Visual
{
	#region TabMouseEventArgs

	/// <summary>
	/// Class containing information about a Tab mouse event.
	/// </summary>
	public class TabMouseEventArgs
		: EventArgs
	{
		#region Fields

		private TabPage _tabPage = null;

		#endregion

		#region Properties

		/// <summary>
		/// Gets or sets the TabPage associated with the TabMouseEventArgs.
		/// </summary>
		[Browsable(false)]
		[Description("Gets or sets the TabPage associated with the TabMouseEventArgs.")]
		public TabPage TabPage
		{
			get { return _tabPage; }
			set { _tabPage = value; }
		}

		#endregion

		/// <summary>
		/// Initializes a new instance of TabMouseEventArgs.
		/// </summary>
		public TabMouseEventArgs()
		{
		}

		/// <summary>
		/// Initializes a new instance of TabMouseEventArgs.
		/// </summary>
		/// <param name="page">TabPage associated with the TabMouseEventArgs.</param>
		public TabMouseEventArgs(TabPage page)
		{
			this.TabPage = page;
		}
	}

	#endregion

	/// <summary>
    /// Represents a TabControl in which the visible Form can be 
    /// changed by changing the SelectedTab.
    /// </summary>
    public class DockTab
        : TabControl
    {
        #region Fields

        private int          _hoverIndex   = -1;
        private StringFormat _stringFormat = null;

		private DockRenderer _renderer  = null;
		private DockPanel    _dockPanel = null;
		private DockPane     _dockPane  = null;

		#region Events

		/// <summary>
		/// Occurs when the user's mouse enters a Tab.
		/// </summary>
		public event TabMouseEventHandler TabMouseEnter;

		/// <summary>
		/// Occurs when the user's mouse leaves a Tab.
		/// </summary>
		public event TabMouseEventHandler TabMouseLeave;

		#endregion

		#region Delegates

		/// <summary>
		/// Represents the method that will handle the TabMouseEnter 
		/// event or the TabMouseLeave event.
		/// </summary>
		/// <param name="sender">Sender object.</param>
		/// <param name="e">TabMouseEventArgs.</param>
		public delegate void TabMouseEventHandler(object sender, TabMouseEventArgs e);

		#endregion

		#endregion

		#region Properties

		/// <summary>
		/// Gets or sets the DockRenderer of the DockTab.
		/// </summary>
		[Browsable(false)]
		[Description("Gets or sets the DockRenderer of the DockTab.")]
		public DockRenderer Renderer
		{
			get { return _renderer; }
			set
			{
				_renderer = value;
				this.Invalidate();
			}
		}

		/// <summary>
        /// Gets the index of the tab the user is currently hovering 
        /// over with the mouse.
        /// </summary>
		[Browsable(false)]
		[Description("Gets the index of the tab the user is currently hovering over with the mouse.")]
        public int HoverIndex
        {
            get { return _hoverIndex; }
        }

		/// <summary>
		/// Gets the StringFormat used to draw the TabPages' text.
		/// </summary>
		[Browsable(false)]
		[Description("Gets the StringFormat used to draw the TabPages' text.")]
		public StringFormat StringFormat
		{
			get { return _stringFormat; }
		}

		/// <summary>
		/// Gets or sets the parent DockPanel.
		/// </summary>
		[Browsable(true)]
		[Description("Gets or sets the parent DockPanel.")]
		public DockPanel DockPanel
		{
			get { return _dockPanel; }
			set
			{
				_dockPanel = value;

				// Update the DockPanel/DockPane fields of the
				// DockCaption to make sure the DockCaption is
				// where it should be.

				_dockPanel.Controls.Add(this);
				this.Parent = _dockPanel;

				if (_dockPanel.DockPane != null)
					_dockPane = _dockPanel.DockPane;
			}
		}

		/// <summary>
		/// Gets the parent DockPane.
		/// </summary>
		[Browsable(false)]
		[Description("Gets the parent DockPane.")]
		public DockPane DockPane
		{
			get { return _dockPane; }
		}

        #endregion

        #region Methods

        #region Internal

		/// <summary>
		/// Calls InvokePaint and InvokePaintBackground.
		/// </summary>
		/// <param name="c">Control for the invokes.</param>
		/// <param name="e">PaintEventArgs for the invokes.</param>
		internal void InvokePaintAll(Control c, PaintEventArgs e)
		{
			this.InvokePaint(c, e);
			this.InvokePaintBackground(c, e);
		}

        #endregion

		#region Protected

		protected override void OnPaint(PaintEventArgs e)
		{
			this.Renderer.TabPaintBackground(this, e.Graphics);
			for (int i = 0; i < this.TabCount; i++)
			{
				this.Renderer.TabDrawTab(this, e.Graphics,
					this.TabPages[i], i);
			}

			base.OnPaint(e);
		}

		protected override void OnPaintBackground(PaintEventArgs pevent)
		{
			this.Renderer.TabPaintBackground(this,
				pevent.Graphics);
		}

		protected override void OnMouseMove(MouseEventArgs e)
		{
			bool foundItem = false;
			int index = -1;
			foreach (TabPage page in this.TabPages)
			{
				index++;
				if (this.GetTabRect(index).Contains
					(e.Location) == true)
				{
					_hoverIndex = index;
					this.Invalidate();
					foundItem = true;

					if (this.TabMouseEnter != null)
					{
						TabMouseEventArgs tabArgs = new TabMouseEventArgs();
						tabArgs.TabPage = page;

						this.TabMouseEnter(this, tabArgs);
					}
				}
				else if (foundItem == false)
				{
					_hoverIndex = -1;
					this.Invalidate();

					if (this.TabMouseLeave != null)
					{
						TabMouseEventArgs tabArgs = new TabMouseEventArgs();
						tabArgs.TabPage = page;

						this.TabMouseLeave(this, tabArgs);
					}
				}
			}

			base.OnMouseMove(e);
		}

		protected override void OnMouseLeave(EventArgs e)
		{
			_hoverIndex = -1; 	// Reset HoverIndex.
			this.Invalidate();

			if (this.TabMouseLeave != null)
			{
				TabMouseEventArgs tabArgs = new TabMouseEventArgs();
				tabArgs.TabPage = null;

				this.TabMouseLeave(this, tabArgs);
			}

			base.OnMouseLeave(e);
		}

		#endregion

		#endregion

		/// <summary>
        /// Initializes a new instance of DockTab.
        /// </summary>
        public DockTab()
        {
			_renderer = new DockRenderer();

            // Call SetStyle multiple times to prevent flickering.

            this.SetStyle(ControlStyles.UserPaint, true);
            this.SetStyle(ControlStyles.OptimizedDoubleBuffer, true);
            this.SetStyle(ControlStyles.ResizeRedraw, true);
            this.SetStyle(ControlStyles.SupportsTransparentBackColor, true);

			// Setup the settings of the base TabControl.
			this.Dock = DockStyle.Fill;
			this.BackColor = this.Renderer.DockColorTable.TabBodyBackColor;
			this.Font = this.Renderer.DockColorTable.PaneFont;
			this.Alignment = TabAlignment.Bottom;

            // Initialize the StringFormat that we use for drawing
            // text on the tabs.

            _stringFormat = new StringFormat();
            _stringFormat.Alignment = StringAlignment.Center;
            _stringFormat.LineAlignment = StringAlignment.Center;
        }
    }
}

using System;
using System.Collections;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Design;
using System.Linq;
using System.Text;
using System.Windows.Forms;

using Storm;
using Storm.Docking;
using Storm.Docking.Controls;
using Storm.Docking.Visual;
using Storm.Docking.Visual.Drawing;
using Storm.Docking.Visual.Glyphs;
using Storm.Docking.Win32;

namespace Storm.Docking.Visual.Drawing
{
	/// <summary>
	/// Class used for drawing all Controls in a DockPane.
	/// </summary>
	public class DockRenderer
	{
		#region Fields

		private DockColorTable _colorTable = null;

		#endregion

		#region Properties

		/// <summary>
		/// Gets or sets the color table of the DockRenderer.
		/// </summary>
		public virtual DockColorTable DockColorTable
		{
			get { return _colorTable; }
			set { _colorTable = value; }
		}

		#endregion

		#region Methods

		#region Public

		#region DockCaption

		public virtual void CaptionDrawBar(DockCaption c, Graphics g)
		{
			Color startColor = DockColorTable.CaptionNormalColorStart;
			Color endColor = DockColorTable.CaptionNormalColorEnd;
			Color textColor = DockColorTable.CaptionNormalTextForeColor;

			if (c.Focused == true)
			{
				startColor = DockColorTable.CaptionFocusColorStart;
				endColor = DockColorTable.CaptionFocusColorEnd;
				textColor = DockColorTable.CaptionFocusTextForeColor;
			}

			LinearGradientBrush brush = new LinearGradientBrush
				(c.Bounds.Location, new Point(c.Bounds.
					Location.X, c.Bounds.Location.Y +
					c.Size.Height), startColor, endColor);

			float diameter = DockColorTable.CaptionRadius * 2.0F;
			SizeF sizeF = new SizeF(diameter, diameter);

			GraphicsPath path = new GraphicsPath();
			RectangleF arc = new RectangleF(new PointF
				(c.Location.X, c.Location.Y), sizeF);

			// We have created our arc Rectangle - start 
			// creating the GraphicsPath.

			// Top left arc.

			path.AddArc(arc, 180, 90);

			// Top right arc.

			arc.X = c.Bounds.Right - diameter;
			path.AddArc(arc, 270, 90);

			// Base rectangle.

			path.AddRectangle(new Rectangle(new Point((int)path.
				PathPoints[0].X, (int)path.PathPoints[0].Y),
				c.Size));

			// Finally close the path and draw it.

			path.CloseFigure();

			g.FillPath(brush, path);
			g.DrawPath(BrushStack.GetPen(DockColorTable
				.CaptionBorderColor), path);

			// We will then draw our text. We use Graphics
			// drawing for this instead of a Label because
			// Labels block MouseDown events.

			// First calculate the place that the text
			// should be placed - we want the text to
			// be placed in the left side of the 
			// DockCaption, so position it there.

			PointF textPoint = new PointF(c.Location.X + 1,
				c.Location.Y + (c.Size.Height / 2)
				- (c.Font.GetHeight() / 2));

			g.DrawString(c.CaptionText, c.Font,
				BrushStack.GetBrush(textColor), textPoint);
		}

		#endregion

		#region DockTab

		public virtual void TabPaintBackground(DockTab t, Graphics g)
		{
			t.ClientRectangle.Offset(t.Location);
			PaintEventArgs e = new PaintEventArgs(g, t.ClientRectangle);
			GraphicsState state = g.Save();
			g.SmoothingMode = SmoothingMode.AntiAlias;

			try
			{
				g.TranslateTransform((float)-t.Location.X,
					(float)-t.Location.Y);

				t.InvokePaintAll(t.Parent, e);
			}
			finally
			{
				g.Restore(state);
				t.ClientRectangle.Offset(-t.Location.X, -t.Location.Y);
			}
		}

		public virtual void TabDrawTab(DockTab t, Graphics g, TabPage tabPage, int index)
		{
			Rectangle recBounds = t.GetTabRect(index);
			RectangleF tabTextArea = (RectangleF)t.GetTabRect(index);
			RectangleF tabArea = tabTextArea;

			Color tabColorStart = DockColorTable.TabNormalBackColorStart;
			Color tabColorEnd = DockColorTable.TabNormalBackColorEnd;
			Color tabBorderColor = DockColorTable.TabNormalBorderColor;
			Color textColor = DockColorTable.TabNormalForeColor;

			bool selected = t.SelectedIndex == index;
			bool hovering = t.HoverIndex == index && selected == false;
			if (selected == true)
			{
				// Update the earlier specified Colors to match that
				// the tab is focused instead of normal.

				tabColorStart = DockColorTable.TabFocusBackColorStart;
				tabColorEnd = DockColorTable.TabFocusBackColorEnd;
				tabBorderColor = DockColorTable.TabFocusBorderColor;
				textColor = DockColorTable.TabFocusForeColor;
			}

			if (hovering == true)
			{
				// Update the earlier specified Colors to match that
				// the tab is hovered over instead of normal.

				tabColorStart = DockColorTable.TabHoverBackColorStart;
				tabColorEnd = DockColorTable.TabHoverBackColorEnd;
				tabBorderColor = DockColorTable.TabHoverBorderColor;
				textColor = DockColorTable.TabHoverForeColor;
			}

			// Now that our Colors has been setup, we will start 
			// drawing the tab.

			Rectangle rect = new Rectangle(new Point((int)tabArea.X,
				(int)tabArea.Y), new Size((int)tabArea.Size.Width - 1,
				(int)tabArea.Size.Height - 4));

			LinearGradientBrush brush = new LinearGradientBrush
				(rect, tabColorStart, tabColorEnd, 90f);

			g.FillRoundedRectangle(brush, rect, (int)DockColorTable.
				TabRadius, RectangleEdgeFilter.BottomLeft |
				RectangleEdgeFilter.BottomRight);

			g.DrawRoundedRectangle(BrushStack.GetPen(tabBorderColor),
				rect, (int)DockColorTable.TabRadius,
				RectangleEdgeFilter.BottomLeft | RectangleEdgeFilter.
				BottomRight);

			if ((tabPage.ImageIndex >= 0) && (t.ImageList != null) &&
				(t.ImageList.Images[tabPage.ImageIndex] != null))
			{
				int leftMargin = 8;
				int rightMargin = 2;

				Image image = t.ImageList.Images[tabPage.ImageIndex];
				Rectangle imageBounds = new Rectangle(recBounds.X +
					leftMargin, recBounds.Y + 1,
					image.Width, image.Height);

				float adjust = (float)(leftMargin + image.Width +
					rightMargin);

				imageBounds.Y += (recBounds.Height - image.Height) / 2;
				tabArea.X += adjust;
				tabArea.Width -= adjust;

				g.DrawImage(image, imageBounds);
			}

			Brush textBrush = BrushStack.GetBrush(textColor);
			g.DrawString(tabPage.Text, t.Font, textBrush,
				tabTextArea, t.StringFormat);
		}

		#endregion

		#region Glyph

		/// <summary>
		/// Draws the Glyph as if the cursor was hovering over it.
		/// </summary>
		/// <param name="g">Graphics to draw with.</param>
		public virtual void GlyphDrawHover(Glyph glyph, Graphics g)
		{
			Color penColor = DockColorTable.GlyphNormalBorderColor;
			Color fillColorStart = DockColorTable.GlyphNormalFillColorStart;
			Color fillColorEnd = DockColorTable.GlyphNormalFillColorEnd;
			int radius = 2;

			if (glyph.DockCaption.Focused == true)
			{
				penColor = DockColorTable.GlyphHoverBorderColor;
				fillColorStart = DockColorTable.GlyphHoverFillColorStart;
				fillColorEnd = DockColorTable.GlyphHoverFillColorEnd;
			}

			LinearGradientBrush brush = new LinearGradientBrush(glyph.GlyphRect,
				fillColorStart, fillColorEnd, LinearGradientMode.Vertical);

			g.SmoothingMode = SmoothingMode.HighQuality;
			g.FillRoundedRectangle(brush, glyph.GlyphRect, radius);
			Rectangle borderRect = glyph.GlyphRect;

			borderRect.Width--;
			borderRect.Height--;

			g.DrawRoundedRectangle(BrushStack.GetPen(penColor),
				borderRect, radius);
		}

		/// <summary>
		/// Draws the Glyph as if the mouse had clicked it.
		/// </summary>
		/// <param name="g">Graphics to draw with.</param>
		public virtual void GlyphDrawPressed(Glyph glyph, Graphics g)
		{
			Color penColor = DockColorTable.GlyphPressedBorderColor;
			Color fillColorStart = DockColorTable.GlyphPressedFillColorStart;
			Color fillColorEnd = DockColorTable.GlyphPressedFillColorEnd;
			int radius = 2;

			LinearGradientBrush brush = new LinearGradientBrush(glyph.GlyphRect,
				fillColorStart, fillColorEnd, LinearGradientMode.Vertical);

			g.SmoothingMode = SmoothingMode.HighQuality;
			g.FillRoundedRectangle(brush, glyph.GlyphRect, radius);
			Rectangle borderRect = glyph.GlyphRect;

			borderRect.Width--;
			borderRect.Height--;

			g.DrawRoundedRectangle(BrushStack.GetPen(penColor),
				borderRect, radius);
		}

		#endregion

		#endregion

		#endregion

		/// <summary>
		/// Initializes a new instance of DockRenderer.
		/// </summary>
		public DockRenderer()
		{
			_colorTable = new DockColorTable();
		}
	}
}

Re: Owner drawn TabControl doesn't act as I want it

WebMaster17-Oct-09 21:28

WebMaster

17-Oct-09 21:28

Bump

Re: Owner drawn TabControl doesn't act as I want it

Dave Kreskowiak18-Oct-09 2:33

Dave Kreskowiak

18-Oct-09 2:33

Bumping does you no good around here.

The reason your question is getting voted down is because of the massive code snippets you posted. Most people simply are not going to look through all of that.

I don't see where your code is doing its own transparency or what you expect to see through the background of your control. If you're using Control.Transparent in your code, all you're really doing is telling the control to take on the background properties of the control that contains your control. You will not see the contents of parent containers or other windows and controls through the "transparency".

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008
But no longer in 2009...

Indexing a property that returns an array. [modified]

C^aptainS^eeS^harp16-Oct-09 17:15

C^aptainS^eeS^harp

16-Oct-09 17:15

Consider the following...

byte[] theArray = new byte[2];

byte[] TheArray
{
  get { return theArray; }
}

//and then I do this...

byte a = TheArray[0];

TheArray[1] = 255;

Can anyone explain what happens? I would assume a function call to get would be executed for each = TheArray[i]; Correct? What about TheArray[1] = 255;? If there is no set method it should still work, right? If not, I know it would if it were a method that returned an array. TheArray()[1] = 255; I guess my question is, does the C# compiler optimize this code so function calls are not performed when accessing the array through property and method invocations?

How would the set property method work with the indexer? Is that possible? What is the point in it if it were not. Allowing properties that handle arrays seems illogical, especially in the set method and in that you can index it like in the code sample, but.. and @!$#% WTF | :WTF:

Fall of the Republic[^]

modified on Friday, October 16, 2009 11:24 PM

Re: Indexing a property that returns an array. [modified]

Luc Pattyn16-Oct-09 17:49

Re: Indexing a property that returns an array.

16-Oct-09 17:49

Hi,

the statement a = TheArray[0]; contains three operations:
1. getting an array (TheArray)
2. getting an element (TheArray[0])
3. assigning a value (to a)

the statement TheArray[1]=255; contains three operations:
1. evaluating an expression (255)
2. getting an array (TheArray)
3. setting an element (TheArray[1])

So in both cases it is the array getter that is used, that is why it works.
An array setter property would be used to assign a new array, as in TheArray=new byte[] {1,2,3,4};

If you want a property that works on a specific array element, then:
- the type should be byte, not byte[], as only one element will be operated upon
- the index must be known somehow (by being fixed, or as a parameter); when a parameter is required it no longer is a property, it becomes a method as in byte GetArrayElementAt(int index) or SetArratElementAt(int index, byte val)

There is a way to use an indexer, however that is not a general solution, as it doesn't have an identifier (it uses "this" to refer to the class), see here[^]; so for an int indexer, you can only do it once on a class (however, you can do another indexer with say a string index).

Smile | :)

Luc Pattyn

I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

Local announcement (Antwerp region): Lange Wapper? Neen!

modified on Friday, October 16, 2009 11:55 PM

dojohansen18-Oct-09 0:59

dojohansen

18-Oct-09 0:59

And this is why the Design Guidelines for Class Library Developers advice against using array type properties. Normally encapsulation will require that you clone the array before "giving it" to anyone, and since this can be expensive (if the array is large) it is important to signify the fact to the user of the class by providing a method and not a property.

byte[] bytes;

public byte[] GetBytes()
{
  return (byte[])bytes.Clone();
}

Couple of questions regarding Windows Service in C#

Aryan S16-Oct-09 17:14

Aryan S

16-Oct-09 17:14

Hi,

I am developing a Windows service in C#. I have couple of question on that.

1. Is it possible to set a Start up parameter during installation of the service? I know that I can pass a parameter while calling ServiceController.Start() method. But the service start type is Autometic and I want the service to run everytime with the same parameter.

2. Is it possible to uninstall the service from within. Say if I meet certain criteria in the service work flow, I want to uninstall the service. Is it possible?

Thanks.

Re: Couple of questions regarding Windows Service in C#

Dave Kreskowiak16-Oct-09 18:22

Dave Kreskowiak

16-Oct-09 18:22

Aryan S wrote:
1. Is it possible to set a Start up parameter during installation of the service? I know that I can pass a parameter while calling ServiceController.Start() method. But the service start type is Autometic and I want the service to run everytime with the same parameter.

Store the parameters in the Registry or in a config file somewhere.

Aryan S wrote:
2. Is it possible to uninstall the service from within. Say if I meet certain criteria in the service work flow, I want to uninstall the service. Is it possible?

I've never heard of a service uninstalling itself. Doesn't mean it's not possible though.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008
But no longer in 2009...

Re: Couple of questions regarding Windows Service in C#

PIEBALDconsult17-Oct-09 5:40

PIEBALDconsult

17-Oct-09 5:40

1) Store it somewhere -- I use a database

2) I doubt it; you can't uninstall a running Service

... but maybe you could Start a Process that will stop and uninstall the Service.

Form flickering problem

SimpleData16-Oct-09 9:55

SimpleData

16-Oct-09 9:55

Hi,
My application has a heavy form (meaning with lots of images etc.) and after I minimize it and then maximize it the form flickers for 2-3 seconds. I've tried to set DoubleBuffered property of my form to true and tried all kinds of SetStyle combinations but nothing helped. Is there anyone out there who has any idea how I can solve this problem or workaround it?

Thanks in advance.

Re: Form flickering problem

Luc Pattyn16-Oct-09 10:25