This documentation is archived and is not being maintained.

Color.FromArgb Method (Int32, Int32, Int32, Int32)

Creates a Color structure from the four ARGB component (alpha, red, green, and blue) values. Although this method allows a 32-bit value to be passed for each component, the value of each component is limited to 8 bits.

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

public static Color FromArgb(
	int alpha,
	int red,
	int green,
	int blue
)

Parameters

alpha
Type: System.Int32

The alpha component. Valid values are 0 through 255.

red
Type: System.Int32

The red component. Valid values are 0 through 255.

green
Type: System.Int32

The green component. Valid values are 0 through 255.

blue
Type: System.Int32

The blue component. Valid values are 0 through 255.

Return Value

Type: System.Drawing.Color
The Color that this method creates.

ExceptionCondition
ArgumentException

alpha, red, green, or blue is less than 0 or greater than 255.

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:

  • Creates three brushes, each a different color. Each Color structure that is used to create a brush is created from four component values (alpha, red, green, blue).

  • Uses an imaginary triangle to position three circles.

  • Paints three overlapping circles, each centered on one vertex of the triangle, using a different brush for each circle.

public void FromArgb1(PaintEventArgs e)
{
    Graphics     g = e.Graphics;

    // Transparent red, green, and blue brushes.
    SolidBrush trnsRedBrush = new SolidBrush(Color.FromArgb(120, 255, 0, 0));
    SolidBrush trnsGreenBrush = new SolidBrush(Color.FromArgb(120, 0, 255, 0));
    SolidBrush trnsBlueBrush = new SolidBrush(Color.FromArgb(120, 0, 0, 255));

    // Base and height of the triangle that is used to position the 
    // circles. Each vertex of the triangle is at the center of one of the 
    // 3 circles. The base is equal to the diameter of the circles. 
    float   triBase = 100;
    float   triHeight = (float)Math.Sqrt(3*(triBase*triBase)/4);

    // Coordinates of first circle's bounding rectangle. 
    float   x1 = 40;
    float   y1 = 40;

    // Fill 3 over-lapping circles. Each circle is a different color.
    g.FillEllipse(trnsRedBrush, x1, y1, 2*triHeight, 2*triHeight);
    g.FillEllipse(trnsGreenBrush, x1 + triBase/2, y1 + triHeight,
        2*triHeight, 2*triHeight);
    g.FillEllipse(trnsBlueBrush, x1 + triBase, y1, 2*triHeight, 2*triHeight);
}

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
Show: