Grey images in TreeView

[Fabio Cannizzo via .NET 247]

The TreeNode of my TreeView have a property that identify if the node as active or inactive.

I would like the Image associated with the particular inactive nodes to appear greyed.

My idea was to load two copies of each image in the ImageList, one normal and one greyed, but I do not know how to create a greyed bitmap from a normal bitmap.

Can anybody help?

Thanks,
Fabio

 

[Frank Eller]

Hi Fabio,

I do not know how to create a greyed
bitmap from a normal bitmap.

Use:
Photoshop
Corel Photopaint
PaintShop Pro
....
any Graphics program can do it.

You can of course also use .NET :

using System;
using System.Drawing;
using System.Drawing.Imaging;

....

public static Bitmap CreateGrayscaledBitmap( Image image )
{
// Create new Bitmap with size of the original bitmap
Bitmap bitmap = new Bitmap( image.Width, image.Height );

// create a matrix to convert the colors
ColorMatrix colorMatrix = new ColorMatrix( new float[][] {
new float[] {0.3F, 0.3F, 0.3F, 0, 0},
new float[] {0.59F, 0.59F, 0.59F, 0, 0},
new float[] {0.11F, 0.11F, 0.11F, 0, 0},
new float[] {0, 0, 0, 1, 0},
new float[] {0, 0, 0, 0, 1}
} );

ImageAttributes imageAttributes = new ImageAttributes();
imageAttributes.SetColorMatrix( colorMatrix );
Graphics g = Graphics.FromImage( bitmap );
g.DrawImage( image, new Rectangle( 0, 0, image.Width, image.Height ),
0, 0, image.Width, image.Height, GraphicsUnit.Pixel,
imageAttributes );
g.Dispose();

return bitmap;
}

Regards,

Frank Eller
www.frankeller.de

 

[Tim Wilson]

As an alternative to using a ColorMatrix, you could also use the static
DrawImageDisabled method of the ControlPaint class.

--
Tim Wilson
..Net Compact Framework MVP

Hi Fabio,

I do not know how to create a greyed
bitmap from a normal bitmap.

Use:
Photoshop
Corel Photopaint
PaintShop Pro
...
any Graphics program can do it.

You can of course also use .NET :

using System;
using System.Drawing;
using System.Drawing.Imaging;

...

public static Bitmap CreateGrayscaledBitmap( Image image )
{
// Create new Bitmap with size of the original bitmap
Bitmap bitmap = new Bitmap( image.Width, image.Height );

// create a matrix to convert the colors
ColorMatrix colorMatrix = new ColorMatrix( new float[][] {
new float[] {0.3F, 0.3F, 0.3F, 0, 0},
new float[] {0.59F, 0.59F, 0.59F, 0, 0},
new float[] {0.11F, 0.11F, 0.11F, 0, 0},
new float[] {0, 0, 0, 1, 0},
new float[] {0, 0, 0, 0, 1}
} );

ImageAttributes imageAttributes = new ImageAttributes();
imageAttributes.SetColorMatrix( colorMatrix );
Graphics g = Graphics.FromImage( bitmap );
g.DrawImage( image, new Rectangle( 0, 0, image.Width, image.Height ),
0, 0, image.Width, image.Height, GraphicsUnit.Pixel,
imageAttributes );
g.Dispose();

return bitmap;
}

Regards,

Frank Eller
www.frankeller.de