Graphics.FromHwnd(IntPtr) 方法

public:
 static System::Drawing::Graphics ^ FromHwnd(IntPtr hwnd);

public static System.Drawing.Graphics FromHwnd(IntPtr hwnd);

static member FromHwnd : nativeint -> System.Drawing.Graphics

Public Shared Function FromHwnd (hwnd As IntPtr) As Graphics

參數

傳回

此方法會回傳指定的視窗 handle 的新值 Graphics 。

範例

以下程式碼範例是為 Windows Forms 設計的，並需要 PaintEventArgse，這是 Paint 事件處理程序的參數，以及 thisForm，即本例的 Form。 此程式碼會執行下列動作：

• 建立一個新的內部指標變數 hwnd ，並將其設為範例表單的 handle。

• 從把手創造新的 Graphics 。

• 用紅色筆畫一個矩形到新東西 Graphics 。

• 處理新的 Graphics.

public:
   void FromHwndHwnd( PaintEventArgs^ /*e*/ )
   {
      // Get handle to form.
      IntPtr hwnd = this->Handle;

      // Create new graphics object using handle to window.
      Graphics^ newGraphics = Graphics::FromHwnd( hwnd );

      // Draw rectangle to screen.
      newGraphics->DrawRectangle( gcnew Pen( Color::Red,3.0f ), 0, 0, 200, 100 );

      // Dispose of new graphics.
      delete newGraphics;
   }

private void FromHwndHwnd(PaintEventArgs e)
{

    // Get handle to form.
    IntPtr hwnd = this.Handle;

    // Create new graphics object using handle to window.
    Graphics newGraphics = Graphics.FromHwnd(hwnd);

    // Draw rectangle to screen.
    newGraphics.DrawRectangle(new Pen(Color.Red, 3), 0, 0, 200, 100);

    // Dispose of new graphics.
    newGraphics.Dispose();
}

Private Sub FromHwndHwnd(ByVal e As PaintEventArgs)

    ' Get handle to form.
    Dim hwnd As IntPtr = Me.Handle


    ' Create new graphics object using handle to window.
    Dim newGraphics As Graphics = Graphics.FromHwnd(hwnd)

    ' Draw rectangle to screen.
    newGraphics.DrawRectangle(New Pen(Color.Red, 3), 0, 0, 200, 100)

    ' Dispose of new graphics.
    newGraphics.Dispose()
End Sub

備註

你應該總是呼叫該 Dispose 方法來釋放 Graphics 該 FromHwnd 方法所產生的相關資源。