C#实现的Windows剪贴板监视器功能实例【附demo源码下载】

#region Definitions
//Constants for API Calls...
private const int WM_DRAWCLIPBOARD = 0x308;
private const int WM_CHANGECBCHAIN = 0x30D;
//Handle for next clipboard viewer...
private IntPtr mNextClipBoardViewerHWnd;
//API declarations...
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static public extern IntPtr SetClipboardViewer(IntPtr hWndNewViewer);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static public extern bool ChangeClipboardChain(IntPtr HWnd, IntPtr HWndNext);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
public static extern int SendMessage(IntPtr hWnd, int msg, int wParam, int lParam);
#endregion

#region Message Process
//Override WndProc to get messages...
protected override void WndProc(ref Message m)
{
  switch (m.Msg)
  {
    case WM_DRAWCLIPBOARD:
      {
        //The clipboard has changed...
        //##########################################################################
        // Process Clipboard Here :)........................
        //##########################################################################
        SendMessage(mNextClipBoardViewerHWnd, m.Msg, m.WParam.ToInt32(), m.LParam.ToInt32());
        //显示剪贴板中的文本信息
        if (Clipboard.ContainsText())
        {
          label1.Text = Clipboard.GetText();
        }
        //显示剪贴板中的图片信息
        if (Clipboard.ContainsImage())
        {
          pictureBox1.Image = Clipboard.GetImage();
          pictureBox1.Update();
        }
        break;
      }
    case WM_CHANGECBCHAIN:
      {
        //Another clipboard viewer has removed itself...
        if (m.WParam == (IntPtr)mNextClipBoardViewerHWnd)
        {
          mNextClipBoardViewerHWnd = m.LParam;
        }
        else
        {
          SendMessage(mNextClipBoardViewerHWnd, m.Msg, m.WParam.ToInt32(), m.LParam.ToInt32());
        }
        break;
      }
  }
  base.WndProc(ref m);
}
#endregion