MFC(多线程与聊天程序,孙鑫C++第十五讲笔记整理)

#include
#include//这里分两步&＃xff0c;会出现一些问题 #include using namespace std;DWORD WINAPI ThreadProc1(LPVOID lpParameter // thread data);DWORD WINAPI ThreadProc2(LPVOID lpParameter // thread data);int index&＃61;0;
int tickets&＃61;100;HANDLE hMutex;
int main()
{HANDLE hThread1&＃61;CreateThread(NULL,0,ThreadProc1,NULL,0,NULL);HANDLE hThread2&＃61;CreateThread(NULL,0,ThreadProc2,NULL,0,NULL);CloseHandle(hThread1);CloseHandle(hThread2);//hMutex&＃61;CreateMutex(NULL,FALSE,NULL);//创建了一个互斥对象&＃xff0c;第二个参数为FALSE说明当前线程没有拥有该互斥对象hMutex&＃61;CreateMutex(NULL,TRUE,NULL);Sleep(2000);return 0;
}
DWORD WINAPI ThreadProc1(LPVOID lpParameter // thread data)
{while(TRUE){WaitForSingleObject(hMutex,INFINITE);//获取了该互斥对象&＃xff0c;INFINITE是无限时间if(tickets>0){cout<<"the Thread1 sell ticket "<}DWORD WINAPI ThreadProc2(LPVOID lpParameter )
{while(TRUE){WaitForSingleObject(hMutex,INFINITE);//获取了该互斥对象&＃xff0c;INFINITE是无限时间if(tickets>0){cout<<"the Thread2 sell ticket "<}


此时的主线程Main是占着茅坑不拉屎&＃xff0c;因为互斥对象中ID计数是1&＃xff0c;下面两个线程不能拥有互斥对象。

要想解决这个问题&＃xff0c;只能在主线程中使用 ReleaseMutex方法&＃xff0c;而不能是在线程1&＃xff0c;线程2中的WaitForSingleObject前面使用ReleaseMutex&＃xff0c;谁拥有的&＃xff0c;谁去释放。

#include
#include//这里分两步&＃xff0c;会出现一些问题 #include using namespace std;DWORD WINAPI ThreadProc1(LPVOID lpParameter // thread data);DWORD WINAPI ThreadProc2(LPVOID lpParameter // thread data);int index&＃61;0;
int tickets&＃61;100;HANDLE hMutex;
int main()
{HANDLE hThread1&＃61;CreateThread(NULL,0,ThreadProc1,NULL,0,NULL);HANDLE hThread2&＃61;CreateThread(NULL,0,ThreadProc2,NULL,0,NULL);CloseHandle(hThread1);CloseHandle(hThread2);//hMutex&＃61;CreateMutex(NULL,FALSE,NULL);//创建了一个互斥对象&＃xff0c;第二个参数为FALSE说明当前线程没有拥有该互斥对象hMutex&＃61;CreateMutex(NULL,TRUE,NULL);WaitForSingleObject(hMutex,INFINITE);ReleaseMutex(hMutex);ReleaseMutex(hMutex);Sleep(2000);return 0;
}
DWORD WINAPI ThreadProc1(LPVOID lpParameter // thread data)
{WaitForSingleObject(hMutex,INFINITE);cout<<"Thread1"<}DWORD WINAPI ThreadProc2(LPVOID lpParameter )
{WaitForSingleObject(hMutex,INFINITE);cout<<"Thread2"<}

答案是&＃xff1a;

如果一个线程在结束前没有释放互斥对象&＃xff0c;则操作系统会帮它释放。上面就是最好的解释。

知道返回值&＃xff0c;可以知道上一个线程的互斥是怎么释放的。

创建一个命名的互斥对象&＃xff0c;可以实现“单例模型”设计方法。

#include
#include//这里分两步&＃xff0c;会出现一些问题 #include using namespace std;DWORD WINAPI ThreadProc1(LPVOID lpParameter // thread data);DWORD WINAPI ThreadProc2(LPVOID lpParameter // thread data);int index&＃61;0;
int tickets&＃61;100;HANDLE hMutex;
int main()
{HANDLE hThread1&＃61;CreateThread(NULL,0,ThreadProc1,NULL,0,NULL);HANDLE hThread2&＃61;CreateThread(NULL,0,ThreadProc2,NULL,0,NULL);CloseHandle(hThread1);CloseHandle(hThread2);//hMutex&＃61;CreateMutex(NULL,FALSE,NULL);//创建了一个互斥对象&＃xff0c;第二个参数为FALSE说明当前线程没有拥有该互斥对象//hMutex&＃61;CreateMutex(NULL,TRUE,NULL);hMutex&＃61;CreateMutex(NULL,TRUE,"tickets");if(ERROR_ALREADY_EXISTS&＃61;&＃61;GetLastError()){cout<<"only one Instance can run!"<}
DWORD WINAPI ThreadProc1(LPVOID lpParameter // thread data)
{WaitForSingleObject(hMutex,INFINITE);cout<<"Thread1"<}DWORD WINAPI ThreadProc2(LPVOID lpParameter )
{WaitForSingleObject(hMutex,INFINITE);cout<<"Thread2"<}


下面是一个简单的聊天程序&＃xff1a;

AfxSocketInit用来加载XX库文件&＃xff0c;相当于WIN32中的WSAStartup函数&＃xff1a;

这个函数用在CXXApp中的InitInstance中最合适 包含Afxsock.h 添加到StdAfx.h头文件中

BOOL CChatApp::InitInstance()
{if(!AfxSocketInit()){AfxMessageBox("加载失败");return FALSE;}。。。。

添加成员函数&＃xff1a;

BOOL CChatDlg::InitSocket()
{m_socket&＃61;socket(AF_INET,SOCK_DGRAM,0);if(INVALID_SOCKET &＃61;&＃61;m_socket){AfxMessageBox("套接字创建失败");return FALSE;}SOCKADDR_IN addrserver;addrserver.sin_addr.S_un.S_addr&＃61;htonl(INADDR_ANY);addrserver.sin_family&＃61;AF_INET;addrserver.sin_port&＃61;htons(6000);int revle;revle&＃61;bind(m_socket,(SOCKADDR*)&addrserver,sizeof(SOCKADDR));if(SOCKET_ERROR&＃61;&＃61;revle){closesocket(m_socket);AfxMessageBox("绑定失败");return FALSE;}return TRUE;
}

添加成语变量 结构体&＃xff1a;

struct RECVPARAM
{SOCKET sockparam;HWND hwnd;
};

在OnInitDialog中&＃xff1a;

InitSocket();RECVPARAM *precvparam&＃61;new RECVPARAM;precvparam->sockparam&＃61;m_socket;precvparam->hwnd&＃61;m_hWnd;HANDLE hThread1&＃61;CreateThread(NULL,0,Recvfun,(LPVOID)precvparam,0,NULL);CloseHandle(hThread1);

添加一个成员函数&＃xff08;静态成员函数&＃xff09;&＃xff0c;其实这里使用一个全局的函数更好

static DWORD WINAPI Recvfun(LPVOID lpParameter);//线程函数

DWORD WINAPI CChatDlg::Recvfun(LPVOID lpParameter)
{SOCKET sock&＃61;((RECVPARAM*)lpParameter)->sockparam;HWND hwnd&＃61;((RECVPARAM*)lpParameter)->hwnd;SOCKADDR_IN addrclient;int len&＃61;sizeof(SOCKADDR);char recvBuffer[100];char sendBuffer[100];char tempBuffer[200];int reval;while(TRUE){reval&＃61;recvfrom(sock,recvBuffer,100,0,(SOCKADDR*)&addrclient,&len);if(SOCKET_ERROR &＃61;&＃61;reval)break;sprintf(tempBuffer,"%s 说 %s",inet_ntoa(addrclient.sin_addr),recvBuffer);::PostMessage(hwnd,WM_RECVDATA,0,(LPARAM)tempBuffer);}return 0;
}

头文件&＃xff1a;

#define WM_RECVDATA WM_USER&＃43;1

protected:HICON m_hIcon;// Generated message map functions//{{AFX_MSG(CChatDlg)virtual BOOL OnInitDialog();afx_msg void OnSysCommand(UINT nID, LPARAM lParam);afx_msg void OnPaint();afx_msg HCURSOR OnQueryDragIcon();//}}AFX_MSGafx_msg void OnRecvData(WPARAM wParam,LPARAM lParam);

BEGIN_MESSAGE_MAP(CChatDlg, CDialog)//{{AFX_MSG_MAP(CChatDlg)ON_WM_SYSCOMMAND()ON_WM_PAINT()ON_WM_QUERYDRAGICON()//}}AFX_MSG_MAPON_MESSAGE(WM_RECVDATA,OnRecvData)
END_MESSAGE_MAP()

void CChatDlg::OnRecvData(WPARAM wParam,LPARAM lParam)
{CString str&＃61;(char*)lParam;CString strtemp;GetDlgItemText(ID_JIESHOU,strtemp);str&＃43;&＃61;"\r\n";str&＃43;&＃61;strtemp;SetDlgItemText(ID_JIESHOU,str);}

void CChatDlg::OnSend()
{// TODO: Add your control notification handler code hereDWORD dwIp;((CIPAddressCtrl*)GetDlgItem(ID_IPADDRESS))->GetAddress(dwIp);SOCKADDR_IN addrto;addrto.sin_addr.S_un.S_addr&＃61;htonl(dwIp);addrto.sin_family&＃61;AF_INET;addrto.sin_port&＃61;htons(6000);CString strsend;GetDlgItemText(ID_FASONG,strsend);sendto(m_socket,strsend,strsend.GetLength()&＃43;1,0,(SOCKADDR*)&addrto,sizeof(SOCKADDR));SetDlgItemText(ID_FASONG,"");
}