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Bitmap.MakeTransparent Method (Color)

Makes the specified color transparent for this Bitmap.

Namespace:  System.Drawing
Assembly:  System.Drawing (in System.Drawing.dll)

public void MakeTransparent(
	Color transparentColor
)

Parameters

transparentColor
Type: System.Drawing.Color

The Color structure that represents the color to make transparent.

ExceptionCondition
InvalidOperationException

The image format of the Bitmap is an icon format.

Exception

The operation failed.

When you call [M:System.Drawing.Bitmap.MakeTransparent(System.Drawing.Color]), the bitmap will be converted to the Format32bppArgb format, as this format supports an alpha channel.

The following code example is designed for use with Windows Forms, and it requires PaintEventArgs e, which is a parameter of the Paint event handler. The code performs the following actions:

  • Gets the color of a pixel in a Bitmap.

  • Makes that color transparent for the bitmap.

  • Draws the Bitmap to the screen.

private void MakeTransparent_Example2(PaintEventArgs e)
{

    // Create a Bitmap object from an image file.
    Bitmap myBitmap = new Bitmap("Grapes.gif");

    // Draw myBitmap to the screen.
    e.Graphics.DrawImage(
        myBitmap, 0, 0, myBitmap.Width, myBitmap.Height);

    // Get the color of a background pixel.
    Color backColor = myBitmap.GetPixel(1, 1);

    // Make backColor transparent for myBitmap.
    myBitmap.MakeTransparent(backColor);

    // Draw the transparent bitmap to the screen.
    e.Graphics.DrawImage(
        myBitmap, myBitmap.Width, 0, myBitmap.Width, myBitmap.Height);
}

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
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