C#

shanmugam81 wrote:

proc.WaitforExit(50000);

Application.ThreadException += ThreadExceptionHandler;
Application.Run(new Form1());
Application.ThreadException -= ThreadExceptionHandler;

Application.ThreadException += ThreadExceptionHandler;
try{
   Application.Run(new Form1());
}
finally{
   Application.ThreadException -= ThreadExceptionHandler;
}

public class RestrictedTextBox : TextBox
{
    private const int WM_PASTE = 0x0302;

    protected override void WndProc(ref Message m)
    {
        if (m.Msg == WM_PASTE)
        {
            if (!IsPasteValid())
            {
                m.Result = IntPtr.Zero;
                return;
            }
        }
        base.WndProc(ref m);
    }

    private bool IsPasteValid()
    {
        bool rtn = false;
        IDataObject obj = Clipboard.GetDataObject();
        string pasteString = (string)obj.GetData(typeof(string));
        // Do checks on pasteString here and set rtn to true if OK.
        return rtn;
    }
}