CSemaphore semaphoreWrite(2,2);

/*CSemaphore (LONG lInitialCount=1,LONG lMaxCount=1,LPCTSTR pstrName=NULL,LPSECURITY_ATTRIBUTES lpsaAttributes=NULL);  lInitialCount:信号量对象的初始计数值，即可访问线程数目的初始值；   lMaxCount：信号量对象计数值的最大值，该参数决定了同一时刻  lMaxCount>=lInitialCount才行，否则报错！  可访问由信号量保护的资源的线程最大数目； 后两个参数在同一进程中使用一般为NULL，不作过多讨论；*/CSemaphore semaphoreWrite(2,2); //资源最多访问线程2个，当前可访问线程数2个 char g_Array[10]; //添加三个线程函数： UINT WriteA(LPVOID pParam){CEdit *pEdit=(CEdit*)pParam;pEdit->SetWindowText("");WaitForSingleObject(semaphoreWrite.m_hObject,INFINITE);CString str;for(int i=0;i<10;i++){        pEdit->GetWindowText(str);g_Array[i]='A';str=str+g_Array[i];pEdit->SetWindowText(str);Sleep(1000);}ReleaseSemaphore(semaphoreWrite.m_hObject,1,NULL);return 0;}UINT WriteB(LPVOID pParam){CEdit *pEdit=(CEdit*)pParam;pEdit->SetWindowText("");WaitForSingleObject(semaphoreWrite.m_hObject,INFINITE);CString str;for(int i=0;i<10;i++){        pEdit->GetWindowText(str);g_Array[i]='B';str=str+g_Array[i];pEdit->SetWindowText(str);Sleep(1000);}ReleaseSemaphore(semaphoreWrite.m_hObject,1,NULL);return 0;}UINT WriteC(LPVOID pParam){CEdit *pEdit=(CEdit*)pParam;pEdit->SetWindowText("");WaitForSingleObject(semaphoreWrite.m_hObject,INFINITE);for(int i=0;i<10;i++){g_Array[i]='C';pEdit->SetWindowText(g_Array);Sleep(1000);}ReleaseSemaphore(semaphoreWrite.m_hObject,1,NULL);return 0;}void CMultiThread10Dlg::OnStart() {CWinThread *pWriteA=AfxBeginThread(WriteA,&m_ctrlA,THREAD_PRIORITY_NORMAL,0,CREATE_SUSPENDED);pWriteA->ResumeThread();CWinThread *pWriteB=AfxBeginThread(WriteB,&m_ctrlB,THREAD_PRIORITY_NORMAL,0,CREATE_SUSPENDED);pWriteB->ResumeThread();CWinThread *pWriteC=AfxBeginThread(WriteC,&m_ctrlC,THREAD_PRIORITY_NORMAL,0,CREATE_SUSPENDED); pWriteC->ResumeThread();}