Region.MakeEmpty 方法

定义

命名空间:

System.Drawing

程序集:

System.Drawing.Common.dll

包:

System.Drawing.Common v8.0.0

Source:

Region.cs

将此 Region 初始化为一个空内部。

public:
 void MakeEmpty();

public void MakeEmpty ();

member this.MakeEmpty : unit -> unit

Public Sub MakeEmpty ()

示例

下面的代码示例演示如何使用 Region 构造函数和 MakeEmpty 方法。 此示例旨在与 Windows 窗体 一起使用。 Create窗体，并将以下代码粘贴到窗体中。 FillEmptyRegion在窗体的事件Paint处理方法中调用 方法，作为 ePaintEventArgs传递。

private:
   void FillEmptyRegion( PaintEventArgs^ e )
   {
      // Create a region from a rectangle.
      Rectangle originalRectangle = Rectangle(40,40,40,50);
      System::Drawing::Region^ smallRegion = gcnew System::Drawing::Region( originalRectangle );

      // Call MakeEmpty.
      smallRegion->MakeEmpty();

      // Fill the region in red and draw the original rectangle
      // in black. Note there is nothing filled in.
      e->Graphics->FillRegion( Brushes::Red, smallRegion );
      e->Graphics->DrawRectangle( Pens::Black, originalRectangle );
   }

private void FillEmptyRegion(PaintEventArgs e)
{

    // Create a region from a rectangle.
    Rectangle originalRectangle = new Rectangle(40, 40, 40, 50);
    Region smallRegion = new Region(originalRectangle);

    // Call MakeEmpty.
    smallRegion.MakeEmpty();

    // Fill the region in red and draw the original rectangle
    // in black. Note there is nothing filled in.
    e.Graphics.FillRegion(Brushes.Red, smallRegion);
    e.Graphics.DrawRectangle(Pens.Black, originalRectangle);
}

Private Sub FillEmptyRegion(ByVal e As PaintEventArgs)

    ' Create a region from a rectangle.
    Dim originalRectangle As New Rectangle(40, 40, 40, 50)
    Dim smallRegion As New Region(originalRectangle)

    ' Call MakeEmpty.
    smallRegion.MakeEmpty()

    ' Fill the region in red and draw the original rectangle
    ' in black. Note there is nothing filled in.
    e.Graphics.FillRegion(Brushes.Red, smallRegion)
    e.Graphics.DrawRectangle(Pens.Black, originalRectangle)

End Sub