MessageBox(NULL,"GOOD","OK",MB_OK | MB_SYSTEMMODAL);
可以参照对应的API：
https://msdn.microsoft.com/en-us/library/windows/desktop/ms645505(v=vs.85).aspx
http://blog.csdn.net/muyeyu/article/details/50618468
MessageBox模态对话框[转]
原文：http://www.cnblogs.com/micq/p/6828997.html
