Color.FromKnownColor Method
Creates a Color structure from the specified pre-defined color.
[Visual Basic] Public Shared Function FromKnownColor( _ ByVal color As KnownColor _ ) As Color [C#] public static Color FromKnownColor( KnownColor color ); [C++] public: static Color FromKnownColor( KnownColor color ); [JScript] public static function FromKnownColor( color : KnownColor ) : Color;
Parameters
- color
- An element of the KnownColor enumeration.
Return Value
The Color structure that this method creates.
Remarks
A pre-defined color is also called a known color and is represented by an element of the KnownColor enumeration.
Example
[Visual Basic, C#] The following 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 KnownColors 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.
[Visual Basic, C#] 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.
[Visual Basic] Public Sub KnownColorBrightnessExample(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 Dim count As Integer = 0 ' number of matches found ' 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 [C#] public void KnownColorBrightnessExample(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]; int count = 0; // number of matches found // 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); } }
[C++, JScript] No example is available for C++ or JScript. To view a Visual Basic or C# example, click the Language Filter button
in the upper-left corner of the page.
Requirements
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family