C#调用C++封装的DLL类库的毁掉函数时，系统崩掉vshost32已停止工作

悬赏园豆：20 [已关闭问题] 关闭于 2014-07-31 16:07

C++写的DLL类库，C#调用回调函数时发生错误，程序崩掉：vshost32已停止工作

/// <summary>
    ///用户登录回调
    /// </summary>
    /// <param name="nError">    nError: 登陆服务器错误值.0为登陆成功,其他为错误值</param>
    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    public delegate void OnUserLoginCallBack(bool bl, uint nError);

/// <summary>
        /// 注册用户登录回调
        /// </summary>
        /// <param name="onuserLogin"></param>
        [DllImport("VideoCommunicationDll.dll", EntryPoint = "OnLoginCallBack", CallingConvention = CallingConvention.Cdecl)]
        public static extern void OnLoginCallBack(OnUserLoginCallBack onuserLogin);

C#的调用如下：

//回调函数
public static void onUserLoginCallBack(bool bl, uint nError){
            //Console.WriteLine("onUserLoginCallBack-----" + bl.ToString());
            //bll = bl;
            Console.WriteLine(bl);
        }

//登录按钮
private void button1_Click(object sender, EventArgs e)
        {
            bool a = UnSafeJhq.InitDll();

            
            OnUserLoginCallBack lc = new OnUserLoginCallBack(onUserLoginCallBack);
            UnSafeJhq.OnLoginCallBack(lc);//执行到这里报错
           
            UnSafeJhq.UserLoginEx(textBox1.Text, textBox2.Text, textBox3.Text, 1);
            
            
            
            this.Visible = false;
            //this.Close();
            Form form1 = new Form1();
            Form1.userid = textBox2.Text;
            form1.ShowDialog();
        }