WinForm中的几个小技巧

屏蔽窗体右上角关闭按钮
一、重写OnClosing
protected override void OnClosing(CancelEventArgs e)
{
    if(this.Visible)
    {
        e.Cancel=true;
　　　//

　　  // WHATE TODO 

　　  //
    }
}

二、重写WndProc

protected override void WndProc(ref Message m)

{

const int WM_SYSCOMMAND = 0x0112;

const int SC_CLOSE = 0xF060;

if (m.Msg == WM_SYSCOMMAND && (int) m.WParam == SC_CLOSE)

{

// User clicked close button

this.WindowState = FormWindowState.Minimized;

return;

}

base.WndProc(ref m);

}
更多方法详见：
http://topic.csdn.net/u/20091220/21/5228d0d6-26aa-48b8-81aa-293f7c7339f8.html?94449
http://topic.csdn.net/u/20090419/18/970d8ad9-ed9a-4bd9-a623-81d23106545b.html

 

屏蔽CTRL-V

在WinForm中的TextBox控件没有办法屏蔽CTRL-V的剪贴板粘贴动作，如果需要一个输入框，但是不希望用户粘贴剪贴板的内容，可以改用RichTextBox控件，并且在KeyDown中屏蔽掉CTRL-V键，例子：

private void richTextBox1_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)

{

if(e.Control && e.KeyCode==Keys.V)

e.Handled = true;

}


应用程序单例运行
  #region 单实例运行
       
        /// <summary>
        /// 单实例运行
        /// </summary>
        /// <param name="frm">所要运行的主窗体</param>
        public static void SingleRun(Form frm)
        {
            System.Threading.Mutex mutex = new System.Threading.Mutex(false,"SINGLE_INSTANCE_MUTEX");
            if (!mutex.WaitOne(0, false))
            {
                mutex.Close();
                mutex = null;
            }
            if (mutex != null)
            {
                Application.Run(frm);
            }
            else
            {
                MessageBox.Show("应用程序已启动","信息提示",MessageBoxButtons.OK,MessageBoxIcon.Information);
            }
        }
        #endregion



将控件转换成圆形

        #region 将控件转换为圆形
  [System.Runtime.InteropServices.DllImport("gdi32")]
  private static extern IntPtr BeginPath(IntPtr hdc);
  [System.Runtime.InteropServices.DllImport("gdi32")]
  private static extern int SetBkMode(IntPtr hdc,int nBkMode);  
  const int TRANSPARENT=1;
  [System.Runtime.InteropServices.DllImport("gdi32")]     
  private static extern IntPtr EndPath(IntPtr hdc);
  [System.Runtime.InteropServices.DllImport("gdi32")]
  private static extern IntPtr PathToRegion(IntPtr hdc);
  [System.Runtime.InteropServices.DllImport("gdi32")]
  private static extern int Ellipse(IntPtr hdc,int x1,int y1,int x2,int y2);
  [System.Runtime.InteropServices.DllImport("user32")]
  private static extern IntPtr SetWindowRgn(IntPtr hwnd,IntPtr hRgn,bool bRedraw);
  [System.Runtime.InteropServices.DllImport("user32")]
  private static extern IntPtr GetDC(IntPtr hwnd);
  /// <summary>
  /// 将控件转为圆形
  /// </summary>
  /// <param name="control">控件名</param> 
  public static void MakeControlToCircle(Control[] control)
  {
   IntPtr dc;
   IntPtr region;
   for(int i=0;i<control.Length;i++)
   {
    dc=GetDC(control[i].Handle);
    BeginPath(dc);
    SetBkMode(dc,TRANSPARENT);
    Ellipse(dc,0,0,control[i].Width-3,control[i].Height-2);
    EndPath(dc);
    region=PathToRegion(dc);
    SetWindowRgn(control[i].Handle,region,false);
   }   
  }
        #endregion 


在同一应用程序中同一窗体只打开一个
        /// <summary>
        /// 在同一应用程序中同一窗体只打开一个
        /// </summary>
        /// <param name="frmOpen">要打开的窗体实例</param>
        /// <returns></returns>
        public static void OpenSeamForm(Form frmOpen)
        {
            foreach (Form frm in Application.OpenForms)
            {
                if (frm.Text == frmOpen.Text)
                {
                    frm.Visible = true;
                    frm.WindowState = FormWindowState.Normal;
                    frm.Activate();
                    return;
                }
            }
            frmOpen.Show();
        }