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Color::FromKnownColor Method (KnownColor)

.NET Framework (current version)
 

Creates a Color structure from the specified predefined color.

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

C#
C++
F#
VB
Copy 
public:
static Color FromKnownColor(
	KnownColor color
)

Parameters

color
Type: System.Drawing::KnownColor

An element of the KnownColor enumeration.

Return Value

Type: System.Drawing::Color

The Color that this method creates.

A predefined color is also called a known color and is represented by an element of the KnownColor enumeration.

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

  • Creates an instance of a Color structure, redShade, to be used for comparisons.

  • Iterates through the KnownColor enumeration elements to find all known colors that have the same brightness as redShade. The iterations are terminated when 15 matches are found or the value of the loop counter is greater than the last KnownColor element.

  • During each iteration, saves the KnownColor element—if it matches the criteria—in an array.

  • Uses a brush to paint rectangles.

The first rectangle is painted the color represented by redShade. Each of the other rectangles is painted a KnownColor that matches the brightness of the redShade.

C#
C++
VB
Copy 
void KnownColorBrightnessExample1( PaintEventArgs^ e )
{
   Graphics^ g = e->Graphics;

   // Color structures. One is a variable used for temporary storage. The other
   // is a constant used for comparisons.
   Color someColor = Color::FromArgb( 0 );
   Color redShade = Color::FromArgb( 255, 200, 0, 100 );

   // Array to store KnownColor values that match the brightness of the
   // redShade color.
   array<KnownColor>^colorMatches = gcnew array<KnownColor>(15);

   // Number of matches found.
   int count = 0;

   // Iterate through the KnownColor enums until 15 matches are found.
   for ( KnownColor enumValue = (KnownColor)0; enumValue <= KnownColor::YellowGreen && count < 15; enumValue = enumValue + (KnownColor)1 )
   {
      someColor = Color::FromKnownColor( enumValue );
      if ( someColor.GetBrightness() == redShade.GetBrightness() )
               colorMatches[ count++ ] = enumValue;
   }

   // Display the redShade color and its argb value.
   SolidBrush^ myBrush1 = gcnew SolidBrush( redShade );
   System::Drawing::Font^ myFont = gcnew System::Drawing::Font( "Arial",12 );
   int x = 20;
   int y = 20;
   someColor = redShade;
   g->FillRectangle( myBrush1, x, y, 100, 30 );
   g->DrawString( someColor.ToString(), myFont, Brushes::Black, (float)x + 120, (float)y );

   // Iterate through the matches that were found and display each color that
   // Corresponds with the enum value in the array. also display the name of
   // The KnownColor.
   for ( int i = 0; i < count; i++ )
   {
      y += 40;
      someColor = Color::FromKnownColor( colorMatches[ i ] );
      myBrush1->Color = someColor;
      g->FillRectangle( myBrush1, x, y, 100, 30 );
      g->DrawString( someColor.ToString(), myFont, Brushes::Black, (float)x + 120, (float)y );
   }
}

.NET Framework
Available since 1.1
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