关于异步委托

Question

//开始录像
SendMessage(hwndc, WM_CAP_FILE_SET_CAPTURE_FILEA, 0, SaveVideoFileDialog.FileName);
SendMessage(hwndc, WM_CAP_SEQUENCE, 0, 0);
//停止录像
SendMessage(hwndc, WM_CAP_STOP, 0, 0);
异步委托如何实现？
谢谢。

Answer 1

      AsyncOperation asyncOperation;
      asyncOperation = AsyncOperationManager.CreateOperation(null);
      asyncOperation.Post(
          delegate
          {
              SendMessage(hwndc, WM_CAP_FILE_SET_CAPTURE_FILEA, 0, SaveVideoFileDialog.FileName); 
              SendMessage(hwndc, WM_CAP_SEQUENCE, 0, 0); 
          }, null
          );      asyncOperation.Post(
          delegate
          {
              SendMessage(hwndc, WM_CAP_STOP, 0, 0); 
          }, null
          );

Answer 2

        /// <summary>
        /// 开始录像
         /// </summary>
        /// <param name="path">保存路径</param>
        private void VideoBegin(string path)
        {
            SaveVideoFileDialog = new SaveFileDialog();
            SaveVideoFileDialog.FileName = DateTime.Now.ToString("yyyyMMddhhmmss");
            SaveVideoFileDialog.Filter = "*.avi|*.avi";
            if (SaveVideoFileDialog.ShowDialog() == DialogResult.OK)
            {
                asyncOperation = AsyncOperationManager.CreateOperation(null);
                asyncOperation.Post(
                delegate
                {
                    SendMessage(hwndc, WM_CAP_FILE_SET_CAPTURE_FILEA, 0, SaveVideoFileDialog.FileName);
                    SendMessage(hwndc, WM_CAP_SEQUENCE, 0, 0);
                }, null);            }
        }
        private void btnSaveVideo_Click(object sender, EventArgs e)
        {
            try
            {
                asyncOperation.Post(
                 delegate
                 {
                     SendMessage(hwndc, WM_CAP_STOP, 0, 0);
                 }, null
                 );            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
我想是我理解错了，还是卡。接着需要怎么做？麻烦高手们。自己太菜。
如需代码，可发邮箱上来。我发过去。谢谢。