My Blog Links
Site Links
- d20 RolePlaying Tools
- Custom Controls Workspace
- MSDN
- SmartClient Dev Center
- C# Dev Center
- WinForms.NET
- Wonder of WinForms
- P/Invoke.NET
- Code Project Articles
Currently Reading
Blogroll
- C# FAQ
- Chris Sells
- Cyrus' Blather
- Dave Winer
- Dilbert Comic
- Don Box
- Duncan Mackenzie
- Eric Gunnerson
- James Avery
- Justin Rogers
- MSDN Blog list
- Neil Gaiman
- Robert Scoble
- The Wayward WebLog
- WIL WHEATON dot NET
Archives
- February 2004
- March 2004
- April 2004
- May 2004
- June 2004
- July 2004
- August 2004
- September 2004
- October 2004
- November 2004
- December 2004
- November 2005
Tools
Tuesday, March 02, 2004
Drawing Composite Image...
You know some things are just harder than they should be. I was trying to draw an Image so that it would paint with the selection color, as needed. That way, if the item was selected, its background would composite draw with the selection. You've probably seen this type of functionality in all sorts of WinForms controls. Since a picture is worth a 1000 words, here goes:
My control had an ImageList attached. On the ImageList, the TransparentColor was set to white. So, I thought if I used ImageList.Draw, it would paint it correctly given the TransparentColor. That way when an item was selected, the image would paint with the selection color for the bits of the image that had the transparent color.
Well, needless to say, that didn't work. I had to call the right incarnation of Graphics.DrawImage (mainly one that took an ImageAttributes as a parameter). By setting the right ColorKey in the ImageAttributes, it finally painted correctly. Here's the code:
My control had an ImageList attached. On the ImageList, the TransparentColor was set to white. So, I thought if I used ImageList.Draw, it would paint it correctly given the TransparentColor. That way when an item was selected, the image would paint with the selection color for the bits of the image that had the transparent color.
Well, needless to say, that didn't work. I had to call the right incarnation of Graphics.DrawImage (mainly one that took an ImageAttributes as a parameter). By setting the right ColorKey in the ImageAttributes, it finally painted correctly. Here's the code:
Color lowerColor = Color.FromArgb(250,250,250);
Color upperColor = Color.FromArgb(255,255,255);
ImageAttributes imageAttr = new ImageAttributes();
imageAttr.SetColorKey(lowerColor, upperColor, ColorAdjustType.Default);
g.DrawImage(imageList.Images[imageIndex], rect, 0, 0,
imageList.ImageSize.Width, imageList.ImageSize.Height,
GraphicsUnit.Pixel, imageAttr );
Comments:
Post a Comment