Color::A Property

 

Gets the alpha component value of this Color structure.

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

public:
property unsigned char A {
	unsigned char get();
}

Property Value

Type: System::Byte

The alpha component value of this Color.

The color of each pixel is represented as a 32-bit number: 8 bits each for alpha, red, green, and blue (ARGB). The alpha component specifies the transparency of the color: 0 is fully transparent, and 255 is fully opaque. Likewise, an A value of 255 represents an opaque color. An A value from 1 through 254 represents a semitransparent color. The color becomes more opaque as A approaches 255.

The following code example demonstrates the A, R, G, and B properties of a Color, and the Implicit(Size to SizeF) member.

This example is designed to be used with a Windows Form. Paste the code into the form and call the ShowPropertiesOfSlateBlue method from the form's Paint event-handling method, passing e as PaintEventArgs.

void ShowPropertiesOfSlateBlue( PaintEventArgs^ e )
{
   Color slateBlue = Color::FromName( "SlateBlue" );
   Byte g = slateBlue.G;
   Byte b = slateBlue.B;
   Byte r = slateBlue.R;
   Byte a = slateBlue.A;
   array<Object^>^temp0 = {a,r,g,b};
   String^ text = String::Format( "Slate Blue has these ARGB values: Alpha:{0}, "
   "red:{1}, green: {2}, blue {3}", temp0 );
   e->Graphics->DrawString( text, gcnew System::Drawing::Font( this->Font,FontStyle::Italic ), gcnew SolidBrush( slateBlue ), RectangleF(PointF(0.0F,0.0F),this->Size) );
}

.NET Framework
Available since 1.1
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