Region.Dispose 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

释放此 Region 使用的所有资源。

public:
 virtual void Dispose();

public void Dispose ();

abstract member Dispose : unit -> unit
override this.Dispose : unit -> unit

Public Sub Dispose ()

实现

Dispose()

示例

下面的代码示例演示构造 Region 函数和 Exclude 和 Dispose 方法。

此示例旨在与 Windows 窗体 一起使用。 将代码粘贴到窗体中，并在处理窗体的 Paint 事件时调用 FillRegionExcludingPath 方法，作为 ePaintEventArgs传递。

private:
   void FillRegionExcludingPath( PaintEventArgs^ e )
   {
      // Create the region using a rectangle.
      System::Drawing::Region^ myRegion = gcnew System::Drawing::Region( Rectangle(20,20,100,100) );

      // Create the GraphicsPath.
      System::Drawing::Drawing2D::GraphicsPath^ path = gcnew System::Drawing::Drawing2D::GraphicsPath;

      // Add a circle to the graphics path.
      path->AddEllipse( 50, 50, 25, 25 );

      // Exclude the circle from the region.
      myRegion->Exclude( path );

      // Retrieve a Graphics object from the form.
      Graphics^ formGraphics = e->Graphics;

      // Fill the region in blue.
      formGraphics->FillRegion( Brushes::Blue, myRegion );

      // Dispose of the path and region objects.
      delete path;
      delete myRegion;
   }

private void FillRegionExcludingPath(PaintEventArgs e)
{

    // Create the region using a rectangle.
    Region myRegion = new Region(new Rectangle(20, 20, 100, 100));

    // Create the GraphicsPath.
    System.Drawing.Drawing2D.GraphicsPath path = 
        new System.Drawing.Drawing2D.GraphicsPath();

    // Add a circle to the graphics path.
    path.AddEllipse(50, 50, 25, 25);

    // Exclude the circle from the region.
    myRegion.Exclude(path);

    // Retrieve a Graphics object from the form.
    Graphics formGraphics = e.Graphics;

    // Fill the region in blue.
    formGraphics.FillRegion(Brushes.Blue, myRegion);

    // Dispose of the path and region objects.
    path.Dispose();
    myRegion.Dispose();
}

Private Sub FillRegionExcludingPath(ByVal e As PaintEventArgs)

    ' Create the region using a rectangle.
    Dim myRegion As New Region(New Rectangle(20, 20, 100, 100))

    ' Create the GraphicsPath.
    Dim path As New System.Drawing.Drawing2D.GraphicsPath

    ' Add a circle to the graphics path.
    path.AddEllipse(50, 50, 25, 25)

    ' Exclude the circle from the region.
    myRegion.Exclude(path)

    ' Retrieve a Graphics object from the form.
    Dim formGraphics As Graphics = e.Graphics

    ' Fill the region in blue.
    formGraphics.FillRegion(Brushes.Blue, myRegion)

    ' Dispose of the path and region objects.
    path.Dispose()
    myRegion.Dispose()

End Sub

注解

调用 Dispose 允许重新分配用于 Region 其他目的的资源。

在完成使用 Dispose 后，应调用 Region。 Dispose 方法使 Region 处于不可用状态。 调用 Dispose后，必须释放对 Region 的所有引用，以便垃圾回收器可以回收 占用的内存 Region 。 有关详细信息，请参阅清理非托管资源和实现 Dispose 方法。

注意

每次释放对 Dispose 的最后一个引用前，均应调用 Region。 否则，在垃圾回收器调用 Region 对象的 Finalize 方法之前，该对象正在使用的资源不会被释放。