关于PostThreadMessage能实现进程间通信吗？

3.发送线程消息:

　　优点:简单,方便

　　缺点:能发送的数据太小

　　用到的函数:

　　　　FindWindow //查找窗口

　　　　GetWindowThreadProcessId //获取指定窗口的进程ID和主线程ID

　　　　PostThreadMessage//发送消息到指定线程


 

　　如果是向主线程发送消息,接收线程消息的进程,可以覆盖虚函数PreTranslateMessage来完成消息的处理


 


 　　ProcessA:

view sourceprint?01 //找窗口句柄  

02 HWND hWnd = ::FindWindow(NULL, "ProcessB");  

03   if (hWnd == NULL)  

04   {  

05       return;  

06   }  

07   

08   //主线程ID  

09   DWORD dwThreadID = 0;  

10   //获取指定窗口主线程ID, 第二个参数是进程ID out 传出值.  

11   dwThreadID = ::GetWindowThreadProcessId(hWnd, NULL);  

12   

13   //向主线程发送线程消息  

14 BOOL bRet = ::PostThreadMessage(dwThreadID, WM_USER + 2, 1, 2);  

15   if (!bRet)  

16   {  

17       AfxMessageBox("发送线程消息失败!");  

18   }


 

　　ProcessB:

view sourceprint?01 BOOL CProcessBDlg::PreTranslateMessage(MSG* pMsg)   

02 {  

03     // TODO: Add your specialized code here and/or call the base class  

04     if(pMsg->message == WM_USER + 2)  

05     {  

06         CString txt;  

07         txt.Format("参数1:%d,参数2:%d", pMsg->wParam, pMsg->lParam);  

08         AfxMessageBox(txt);  

09         return TRUE;  

10     }  

11        

12     return CDialog::PreTranslateMessage(pMsg);  

13 }

A:
#define WM_MYMESSAGE WM_USER+1
case WM_COMMAND:
        {
                switch(LOWORD(wParam))
                {
                case IDC_BUTTON1:
                    GetDlgItemText(hwndDlg,IDC_EDIT1,szEditText,MAX_PATH);
                    //用WM_COPYDATA消息实现
                    //MessageBox(hwndDlg,szEditText,TEXT("B"),MB_OK);
                    /*hwndDestination=FindWindow(NULL,TEXT("IPC_B"));
                    copydatastruct.dwData=NULL;
                    copydatastruct.cbData=sizeof(szEditText);
                    copydatastruct.lpData=szEditText;
                    SendMessage(hwndDestination,WM_COPYDATA,(WPARAM)hwndDlg,(LPARAM)&copydatastruct);*/
                    //用内存映射实现如下

                    if(s_hFileMap!=NULL)
                    {
                        if(GetLastError()==ERROR_ALREADY_EXISTS)
                        {
                            MessageBox(hwndDlg,TEXT("映射对象已经存在！"),TEXT("出错"),MB_ICONINFORMATION);
                        }
                        else
                        {
                            pView=MapViewOfFile(s_hFileMap,FILE_MAP_READ|FILE_MAP_WRITE,0,0,0);
                            if(pView!=NULL)
                            {
                                //pView=szEditText;
                                lstrcpy((LPWSTR)pView,szEditText);
                                UnmapViewOfFile(pView);
                                hwndDestination=FindWindow(NULL,TEXT("IPC_B"));
                                dwThreadID=GetWindowThreadProcessId(hwndDestination,NULL);
                                bRet=PostThreadMessage(dwThreadID,WM_MYMESSAGE,0,0);
                                bError=GetLastError();
                                //bRet=SendMessage(hwndDestination,WM_MYMESSAGE,0,0);
                                if(!bRet)
                                {
                                MessageBox(hwndDlg,TEXT("发送消息失败！"),TEXT("错误"),MB_ICONINFORMATION);
                                }
                            }
                            else
                            {
                                MessageBox(hwndDlg,TEXT("不能映射文件视图!"),TEXT("出错"),MB_ICONINFORMATION);
                            }
                        }
                    }
                    else
                    {
                        MessageBox(hwndDlg,TEXT("不能创建映射"),TEXT("出错"),MB_ICONINFORMATION);
                    }
                    return 0;
                default:
                    break;
                }
        }
        return TRUE;

#define WM_MYMESSAGE WM_USER+1
case WM_MYMESSAGE:
        s_hFileMap=OpenFileMapping(FILE_MAP_READ|FILE_MAP_WRITE,0,TEXT("ShareData"));
        if(s_hFileMap!=NULL)
        {
            pView=MapViewOfFile(s_hFileMap,FILE_MAP_READ|FILE_MAP_WRITE,0,0,0);
            if(pView!=NULL)
            {
                SetDlgItemText(hwndDlg,IDC_EDIT1,(LPCWSTR)pView);
                UnmapViewOfFile(pView);
            }
            else
            {
                MessageBox(hwndDlg,TEXT("不能映射文件视图!"),TEXT("出错"),MB_ICONINFORMATION);
            }
        }
        else
        {
            MessageBox(hwndDlg,TEXT("不能打开映射"),TEXT("出错"),MB_ICONINFORMATION);
        }
        break;