Color.FromKnownColor(KnownColor) Method

Definition

Namespace:

System.Drawing

Assembly:

System.Drawing.Primitives.dll

Source:

Color.cs

Creates a Color structure from the specified predefined color.

public:
 static System::Drawing::Color FromKnownColor(System::Drawing::KnownColor color);

public static System.Drawing.Color FromKnownColor (System.Drawing.KnownColor color);

static member FromKnownColor : System.Drawing.KnownColor -> System.Drawing.Color

Public Shared Function FromKnownColor (color As KnownColor) As Color

Parameters

color

KnownColor

An element of the KnownColor enumeration.

Returns

Color

The Color that this method creates.

Examples

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 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 lightness 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 lightness of the redShade.

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 );
   }
}

public 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.
    KnownColor[]  colorMatches = new KnownColor[15];
     
    // Number of matches found.
    int  count = 0;   
          
    // Iterate through the KnownColor enums until 15 matches are found.
    for (KnownColor enumValue = 0;
        enumValue <= KnownColor.YellowGreen && count < 15; enumValue++)
    {
        someColor = Color.FromKnownColor(enumValue);
        if (someColor.GetBrightness() == redShade.GetBrightness())
            colorMatches[count++] = enumValue;
    }
             
    // Display the redShade color and its argb value.
    SolidBrush  myBrush1 = new SolidBrush(redShade);
    Font        myFont = new 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, x + 120, 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, x + 120, y);
    }
}

Public Sub KnownColorBrightnessExample1(ByVal e As PaintEventArgs)
    Dim g As Graphics = e.Graphics

    ' Color structures. One is used for temporary storage. The other
    ' is a constant used for comparisons.
    Dim someColor As Color = Color.FromArgb(0)
    Dim redShade As Color = Color.FromArgb(255, 200, 0, 100)

    ' Array to store KnownColor values that match the brightness of the
    ' redShade color.
    Dim colorMatches(15) As KnownColor

    ' Number of matches found.
    Dim count As Integer = 0

    ' iterate through the KnownColor enums until 15 matches are found.
    Dim enumValue As KnownColor
    For enumValue = 0 To KnownColor.YellowGreen
        someColor = Color.FromKnownColor(enumValue)
        If (someColor.GetBrightness()) = (redShade.GetBrightness()) Then
            colorMatches(count) = enumValue
            count += 1
            If count > 15 Then
                Exit For
            End If
        End If
    Next enumValue

    ' Display the redShade color and its argb value.
    Dim myBrush1 As New SolidBrush(redShade)
    Dim myFont As New Font("Arial", 12)
    Dim x As Integer = 20
    Dim y As Integer = 20
    someColor = redShade
    g.FillRectangle(myBrush1, x, y, 100, 30)
    g.DrawString(someColor.ToString(), myFont, Brushes.Black, _
    x + 120, y)

    ' Iterate through the matches that were found and display each
    ' color that corresponds with the enum value in the array.
    ' Display the name of the KnownColor.
    Dim i As Integer
    For i = 0 To count - 1
        y += 40
        someColor = Color.FromKnownColor(colorMatches(i))
        myBrush1.Color = someColor
        g.FillRectangle(myBrush1, x, y, 100, 30)
        g.DrawString(someColor.ToString(), myFont, Brushes.Black, _
        x + 120, y)
    Next i
End Sub

Remarks

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