小弟在MFC多文档下编写的多线程编码,想运行OnThreadResume() 这个函数线程挂起,OnThreadSuspend()开始线程,但为什么调用了OnThreadResume()函数,在调用OnThreadSuspend() 会报错呢,线程的句柄是NULL呢?求解答啊
UINT CDrawView::DrawLine(LPVOID pParam)
{
PARAM m_pParam=(PARAM)pParam;
CBrush m_Brush;
CWnd m_Wnd;
CDC m_Dc;
//根据线程ID产生对应颜色的画刷
if(m_pParam->m_nID==0)
{
m_Brush.CreateSolidBrush(RGB(255,0,0));
}else if(m_pParam->m_nID==1){
m_Brush.CreateSolidBrush(RGB(0,255,0));
}else{
m_Brush.CreateSolidBrush(RGB(0,0,255));
}
//根据窗口句柄,得到CDC
m_Wnd.Attach(m_pParam->m_hWnd);
m_Dc=m_Wnd.GetDC();
CBrush *m_pOldBrush=(CBrush)m_Dc->SelectObject(&m_Brush);
//重复画矩形,每次前进一个像素
for(int i=1;i<300;i++)
{
m_Dc->Rectangle(10,35+m_pParam->m_nID*50,10+i,55+m_pParam->m_nID*50);
Sleep(100);//让线程暂停100ms,是为了可以明显的看到三个线程是同时执行的
}
//(至少我的肉眼看来是这样的,实际并非如此)
m_Dc->SelectObject(m_pOldBrush);
m_Wnd.Detach();
return 0;
}
void CDrawView::OnThreadResume()
{
// TODO: Add your command handler code here
CString szContent = "确定要开启线程?";
PARAM *m_pParam[THREAD_NUM]={NULL,NULL,NULL};//传入线种入口函数的参数,初始化为空
CWinThread *m_pThread[THREAD_NUM];
for(int i=0;i<THREAD_NUM;i++){
m_pThread[i]=NULL;
m_pParam[i]=new PARAM;
memset((void*)m_pParam[i],0,sizeof(PARAM));//将为入口函数参数分配
//的内存全部置0值
//写入线程ID和窗口句柄
m_pParam[i]->m_nID=i;
m_pParam[i]->m_hWnd=GetSafeHwnd();
//启动线程
//if(IDYES == MessageBox(szContent,NULL,MB_YESNO))
m_pThread[i]=AfxBeginThread(DrawLine,(LPVOID)(m_pParam[i]),THREAD_PRIORITY_NORMAL,0,CREATE_SUSPENDED);
ASSERT(m_pThread[i]);
m_pThread[i]->m_bAutoDelete = FALSE;
//m_pThread[i]->ResumeThread();
//Sleep(10000);
}
}
void CDrawView::OnThreadSuspend()
{
// TODO: Add your command handler code here
for (int i = 0; i < THREAD_NUM; i ++)
{
if (m_pThread[i] == NULL)
{
AfxMessageBox("错误");
}
m_pThread[i]->ResumeThread();
}
}