急急急！我想写个播放器用的大华的库

 internal static class DHWraps
    {

 [DllImport(@"dhvecplay.dll", EntryPoint = "DH_Play264_OpenFile", CallingConvention = CallingConvention.StdCall)]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool DH_Play264_OpenFile(int nPort, string sFileName);

}

窗体

  private void tsmiOpenFile_Click(object sender, EventArgs e)
        {
            try
            {
                OpenFileDialog fileDialog = new OpenFileDialog();
                fileDialog.ShowDialog();
                string filePath = fileDialog.FileName;
                DHWraps.DH_Play264_OpenFile(0, filePath);

                lblTolelTime.Text = DHWraps.DH_Play264_GetFileTime(0).ToString();         

  }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }

        }

为什么程序执行到红色部分则终止了，也没有返回值。程序卡了