Qt+opencv, 出错(Fatal IO error 11)（XInitThreads）

程序运行时，有3种情况：

                                正常;

                                直接报错1;

                                直接报错2。

报错1：

            [xcb] Unknown request in queue while dequeuing

            [xcb] Most likely this is a multi-threaded client and XInitThreads has not been called

            [xcb] Aborting, sorry about that.

            most likely this is a multi-threaded client and XInitThreads.............

报错2：

            Fatal IO error 11 (资源暂时不可用) on X server :0

            Fatal IO Error: 11 (resource temporarily unavailable)

程序很简单，就是主线程不停的从网络摄像头获取图像，显示。

                                次线程从主线程请求图像，处理，显示处理图像，再次请求。

两个线程中都会调用opencv显示图像，导致绘图冲突，应该把绘图操作都放到主线程中处理。

所有的界面操作都应该放在主线程中！