Color.ToArgb 方法

定义

命名空间:

System.Drawing

程序集:

System.Drawing.Primitives.dll

Source:

Color.cs

获取此 Color 结构的 32 位 ARGB 值。

public:
 int ToArgb();

public int ToArgb ();

member this.ToArgb : unit -> int

Public Function ToArgb () As Integer

返回

Int32

此 Color 的 32 位 ARGB 值。

示例

下面的代码示例旨在与 Windows 窗体 一起使用，它需要 PaintEventArgse，这是事件处理程序的参数Paint。 此代码执行以下操作：

• 循环访问 KnownColor 枚举元素以查找具有非零绿色分量和零值红色分量且不是系统颜色的所有已知颜色。

• 在每次迭代期间，如果 KnownColor 元素与条件匹配，则保存在数组中。

• 使用画笔绘制矩形。

每个矩形都绘制一个与第一个项目 KnownColor 符号中所述的条件匹配的 。 KnownColor还会显示 的名称及其组件值。

此示例显示某些已知颜色、颜色的名称及其四个分量值。 方法 ToArgb 用作显示组件值的初步步骤。

void ToArgbToStringExample1( PaintEventArgs^ e )
{
   Graphics^ g = e->Graphics;

   // Color structure used for temporary storage.
   Color someColor = Color::FromArgb( 0 );

   // Array to store KnownColor values that match the criteria.
   array<KnownColor>^colorMatches = gcnew array<KnownColor>(167);

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

   // Iterate through the KnownColor enums to find all corresponding colors
   // that have a nonzero green component and zero-value red component and
   // that are not system colors.
   for ( KnownColor enumValue = (KnownColor)0; enumValue <= KnownColor::YellowGreen; enumValue = enumValue + (KnownColor)1 )
   {
      someColor = Color::FromKnownColor( enumValue );
      if ( someColor.G != 0 && someColor.R == 0 &&  !someColor.IsSystemColor )
               colorMatches[ count++ ] = enumValue;
   }
   SolidBrush^ myBrush1 = gcnew SolidBrush( someColor );
   System::Drawing::Font^ myFont = gcnew System::Drawing::Font( "Arial",9 );
   int x = 40;
   int y = 40;

   // 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 and the ARGB components.
   for ( int i = 0; i < count; i++ )
   {
      // Display the color.
      someColor = Color::FromKnownColor( colorMatches[ i ] );
      myBrush1->Color = someColor;
      g->FillRectangle( myBrush1, x, y, 50, 30 );

      // Display KnownColor name and the four component values. To display the
      // component values:  Use the ToArgb method to get the 32-bit ARGB value
      // of someColor, which was created from a KnownColor. Then create a
      // Color structure from the 32-bit ARGB value and set someColor equal to
      // this new Color structure. Then use the ToString method to convert it to
      // a string.
      g->DrawString( someColor.ToString(), myFont, Brushes::Black, (float)x + 55, (float)y );
      someColor = Color::FromArgb( someColor.ToArgb() );
      g->DrawString( someColor.ToString(), myFont, Brushes::Black, (float)x + 55, (float)y + 15 );
      y += 40;
   }
}

      public void ToArgbToStringExample1(PaintEventArgs e)
      {
          Graphics     g = e.Graphics;
                   
          // Color structure used for temporary storage.
          Color   someColor = Color.FromArgb(0);
                   
          // Array to store KnownColor values that match the criteria.
          KnownColor[]  colorMatches = new KnownColor[167];
          
          // Number of matches found.
          int  count = 0; 

          // Iterate through the KnownColor enums to find all corresponding colors
          // that have a nonzero green component and zero-value red component and
          // that are not system colors.
          for (KnownColor enumValue = 0;
              enumValue <= KnownColor.YellowGreen; enumValue++)
          {
              someColor = Color.FromKnownColor(enumValue);
              if (someColor.G != 0 && someColor.R == 0 && !someColor.IsSystemColor)
                  colorMatches[count++] = enumValue;
          }
          SolidBrush  myBrush1 = new SolidBrush(someColor);
          Font        myFont = new Font("Arial", 9);
          int         x = 40;
          int         y = 40;
                   
          // 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 and the ARGB components.
          for (int i = 0; i < count; i++)
          {
                   
              // Display the color.
              someColor = Color.FromKnownColor(colorMatches[i]);
              myBrush1.Color = someColor;
              g.FillRectangle(myBrush1, x, y, 50, 30);
                   
              // Display KnownColor name and the four component values. To display the
              // component values:  Use the ToArgb method to get the 32-bit ARGB value
              // of someColor, which was created from a KnownColor. Then create a
              // Color structure from the 32-bit ARGB value and set someColor equal to
              // this new Color structure. Then use the ToString method to convert it to
              // a string.
              g.DrawString(someColor.ToString(), myFont, Brushes.Black, x + 55, y);
              someColor = Color.FromArgb(someColor.ToArgb());
              g.DrawString(someColor.ToString(), myFont, Brushes.Black, x + 55, y + 15);
              y += 40;
          }
      }

Public Sub ToArgbToStringExample1(ByVal e As PaintEventArgs)
    Dim g As Graphics = e.Graphics

    ' Color structure used for temporary storage.
    Dim someColor As Color = Color.FromArgb(0)

    ' Array to store KnownColor values that match the criteria.
    Dim colorMatches(167) As KnownColor

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

    ' Iterate through KnownColor enums to find all corresponding colors
    ' that have a non-zero green component and zero-valued red
    ' component and that are not system colors.
    Dim enumValue As KnownColor
    For enumValue = 0 To KnownColor.YellowGreen
        someColor = Color.FromKnownColor(enumValue)
        If someColor.G <> 0 And someColor.R = 0 And _
        Not someColor.IsSystemColor Then
            colorMatches(count) = enumValue
            count += 1
        End If
    Next enumValue
    Dim myBrush1 As New SolidBrush(someColor)
    Dim myFont As New Font("Arial", 9)
    Dim x As Integer = 40
    Dim y As Integer = 40

    ' Iterate through the matches found and display each color that
    ' corresponds with the enum value in the array. Also display the
    ' name of the KnownColor and the ARGB components.
    Dim i As Integer
    For i = 0 To count - 1

        ' Display the color.
        someColor = Color.FromKnownColor(colorMatches(i))
        myBrush1.Color = someColor
        g.FillRectangle(myBrush1, x, y, 50, 30)

        ' Display KnownColor name and four component values. To display
        ' component values:  Use the ToArgb method to get the 32-bit
        ' ARGB value of someColor (created from a KnownColor). Create
        ' a Color structure from the 32-bit ARGB value and set someColor
        ' equal to this new Color structure. Then use the ToString method
        ' to convert it to a string.
        g.DrawString(someColor.ToString(), myFont, Brushes.Black, _
        x + 55, y)
        someColor = Color.FromArgb(someColor.ToArgb())
        g.DrawString(someColor.ToString(), myFont, Brushes.Black, _
        x + 55, y + 15)
        y += 40
    Next i
End Sub

注解

32 位 ARGB 值的字节顺序为 AARRGGBB。 由 AA 表示的最有效字节 (MSB) 是 alpha 分量值。 分别由 RR、GG 和 BB 表示的第二个、第三个和第四个字节是红色、绿色和蓝色的颜色分量