Question

我想在用户定义的面板OnPaint方法中检索更新矩形，但需要此面板的句柄。我徘徊如何获得当前控件的句柄。代码如下：

class MyPanel : Panel
{
  [DllImport("User32.dll")]
  public static extern bool GetUpdateRect(IntPtr hWnd, out Rectangle lpRect, bool bErase);

  protected override void OnPaint(PaintEventArgs e)
  {
    Rectangle updateRect;
    IntPtr hWnd = IntPtr.Zero;
    // hWnd = ?; I wonder how to get handle of this panel
    GetUpdateRect(hWnd, out updateRect, false);

    base.OnPaint(e);
    // following drawing code is omited
  }
}

Answer 1

简易解决方案（因为<form method="GET" action="."></form>已从MyPanel继承而来Control）：

HWND

复杂，但一般情况解决方案（protected override void OnPaint(PaintEventArgs e) { ... // Panel is inherited from Control which has HWND IntPtr hWnd = this.Handle; }可以是任何类，而不是必然 a MyPanel）：

Control

如何在用户定义的控件类中处理当前控件

1 个答案: