判断一个线程是否执行结束以及获取线程退出码

判断一个线程是否执行结束：
HANDLE g_hThread = NULL;

DWORD dw = WaitForSingleObject(g_hThread, 0);

if(dw == WAIT_TIMEOUT)   //线程正在运行
{
TerminateThread(g_hThread, dwExitCode);   //不建议强制结束

if(g_hThread != NULL)
{
CloseHandle(g_hThread);   //关闭线程句柄，可能线程已结束，但句柄还没释放
g_hThread = NULL;
}
DWORD dwThreadId = 0;//新建一个线程
g_hThread = CreateThread(NULL, 0, ThreadFunc, 0, 0, &dwThreadId);
}