C# 2.0 中怎么监视剪贴板的动作????

Question

C# 2.0 中怎么监视剪贴板的动作,比如当将数据放入剪贴板时执行我的代码,对剪贴板中的数据进行查看,是否是指定的格式.

Answer 1

[DllImport("User32.dll")]
        protected static extern int SetClipboardViewer(int hWndNewViewer);        [DllImport("User32.dll", CharSet=CharSet.Auto)]
        public static extern bool ChangeClipboardChain(IntPtr hWndRemove, IntPtr hWndNewNext);        [DllImport("user32.dll", CharSet=CharSet.Auto)]
            public static extern int SendMessage(IntPtr hwnd, int wMsg, IntPtr wParam, IntPtr lParam);
    IntPtr nextClipboardViewer;
    
        protected override void WndProc(ref System.Windows.Forms.Message m)
        {
            // defined in winuser.h
            const int WM_DRAWCLIPBOARD = 0x308;
            const int WM_CHANGECBCHAIN = 0x030D;            switch(m.Msg)
            {
                case WM_DRAWCLIPBOARD:
                    DisplayClipboardData();
                    SendMessage(nextClipboardViewer, m.Msg, m.WParam, m.LParam);
                    break;                case WM_CHANGECBCHAIN:
                    if (m.WParam == nextClipboardViewer)
                        nextClipboardViewer = m.LParam;
                    else
                        SendMessage(nextClipboardViewer, m.Msg, m.WParam, m.LParam);
                    break;                default:
                    base.WndProc(ref m);
                    break;
            }    
            }
    
                private void Form1_Closed(object sender, System.EventArgs e)
        {
            ChangeClipboardChain(this.Handle,NextClipHwnd);
            //从观察链中删除本观察窗口
            SendMessage(NextClipHwnd,WM_CHANGECBCHAIN,this.Handle,NextClipHwnd);
            //将WM_DRAWCLIPBOARD消息传递到下一个观察链中的窗口        
            }
    
        void DisplayClipboardData()        
        {
            try
            {
                IDataObject iData = new DataObject();  
                iData = Clipboard.GetDataObject();                if (iData.GetDataPresent(DataFormats.Rtf)) 
                    richTextBox1.Rtf = (string)iData.GetData(DataFormats.Rtf);
                else if (iData.GetDataPresent(DataFormats.Text))
                    richTextBox1.Text = (string)iData.GetData(DataFormats.Text);
                else
                    richTextBox1.Text = "[Clipboard data is not RTF or ASCII Text]";
            }
            catch(Exception e)
            {
                MessageBox.Show(e.ToString());
            }
            }