Color.FromKnownColor(KnownColor) 方法

定义

基于指定的预定义颜色创建 Color 结构。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

参数

color
KnownColor

KnownColor 枚举的元素。An element of the KnownColor enumeration.

返回

此方法创建的 ColorThe Color that this method creates.

示例

下面的代码示例旨在与 Windows 窗体一起使用,并且它需要 PaintEventArgs e,它是 Paint 事件处理程序的参数。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. 该代码执行下列操作:The code performs the following actions:

  • 创建要用于比较的 Color 结构 redShade的实例。Creates an instance of a Color structure, redShade, to be used for comparisons.

  • 循环访问 KnownColor 枚举元素,查找亮度与 redShade相同的所有已知颜色。Iterates through the KnownColor enumeration elements to find all known colors that have the same lightness as redShade. 如果找到了15个匹配项或循环计数器的值大于最后一个 KnownColor 元素,则将终止迭代。The iterations are terminated when 15 matches are found or the value of the loop counter is greater than the last KnownColor element.

  • 在每次迭代过程中,会保存 KnownColor 元素(如果它匹配数组中的条件)。During each iteration, saves the KnownColor element - if it matches the criteria - in an array.

  • 使用画笔绘制矩形。Uses a brush to paint rectangles.

第一个矩形绘制 redShade表示的颜色。The first rectangle is painted the color represented by redShade. 其他每个矩形都绘制一个与 redShade亮度相匹配的 KnownColorEach 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

注解

预定义的颜色也称为已知颜色,由 KnownColor 枚举的元素表示。A predefined color is also called a known color and is represented by an element of the KnownColor enumeration.

适用于