捕获鼠标单击Form上的任何位置(不使用IMessageFilter)

Question

MouseDown当鼠标位于子控件上时,不会调用该事件.我试过KeyPreview = true;但它没有帮助(虽然它适用于KeyDown- 键盘点击).

我正在寻找类似的东西KeyPreview,但对于鼠标事件.

IMessageFilter如果有更简单的话,我宁愿不使用和处理WinAPI消息.替代方案(另外,IMessageFilter设置应用程序范围.我只想要Form -wide.)迭代所有子控件,订阅每个,都有自己的缺点.

Answer 1

您仍然可以使用MessageFilter并只过滤ActiveForm:

private class MouseDownFilter : IMessageFilter {
  public event EventHandler FormClicked;
  private int WM_LBUTTONDOWN = 0x201;
  private Form form = null;

  [DllImport("user32.dll")]
  public static extern bool IsChild(IntPtr hWndParent, IntPtr hWnd);

  public MouseDownFilter(Form f) {
    form = f;
  }

  public bool PreFilterMessage(ref Message m) {
    if (m.Msg == WM_LBUTTONDOWN) {
      if (Form.ActiveForm != null && Form.ActiveForm.Equals(form)) {
        OnFormClicked();
      }
    }
    return false;
  }

  protected void OnFormClicked() {
    if (FormClicked != null) {
      FormClicked(form, EventArgs.Empty);
    }
  }
}

然后在您的表单中,附上它:

public Form1() {
  InitializeComponent();
  MouseDownFilter mouseFilter = new MouseDownFilter(this);
  mouseFilter.FormClicked += mouseFilter_FormClicked;
  Application.AddMessageFilter(mouseFilter);
}

void mouseFilter_FormClicked(object sender, EventArgs e) {
  // do something...
}