c++ - 在另一个线程(不是主线程)中创建窗口

Question

我有一个函数:

HWND createMainWindow(P2p_Socket_Machine * toSend){

    HWND hMainWnd = CreateWindow( 
        L"Class",/*(LPCWSTR) nameOfConference.c_str()*/L"Chat",  WS_OVERLAPPED | WS_MINIMIZEBOX | WS_SYSMENU, 
    CW_USEDEFAULT, 0, 600,400, 
    (HWND)NULL, (HMENU)NULL, 
    /*(HINSTANCE)hlnstance*/NULL, NULL 
    ); 

    if (!hMainWnd) { 
        MessageBox(NULL, L"Cannot create main window", L"Error", MB_OK); 
        return 0; 
    }

    CreateWindowA("LISTBOX",NULL, WS_CHILD|WS_VISIBLE|WS_BORDER|WS_VSCROLL|LBS_NOTIFY|LBS_MULTIPLESEL,310,30,255,275,hMainWnd,(HMENU)List_Box,NULL,NULL);

    CreateWindowExA(NULL,"BUTTON", "Refresh", WS_TABSTOP|WS_VISIBLE|WS_CHILD|BS_DEFPUSHBUTTON,385,310,100,24,hMainWnd,(HMENU)Button_Refresh, NULL ,NULL);

    CreateWindowExA(NULL,"BUTTON", "Send", WS_TABSTOP|WS_VISIBLE|WS_CHILD|BS_DEFPUSHBUTTON,385,334,100,24,hMainWnd,(HMENU)Button_Send, NULL ,NULL);

    CreateWindowExA(NULL,"BUTTON", "New", WS_TABSTOP|WS_VISIBLE|WS_CHILD|BS_DEFPUSHBUTTON,385,354,100,24,hMainWnd,(HMENU)Button_New, NULL ,NULL);

    CreateWindowA("EDIT",0,WS_BORDER|WS_VISIBLE|WS_CHILD|ES_LEFT|ES_MULTILINE|WS_VSCROLL|WS_DISABLED,
    10,30,265,275,hMainWnd,(HMENU)Text_Box_Get,NULL,NULL);

    CreateWindowA("EDIT",0,WS_BORDER|WS_VISIBLE|WS_CHILD|ES_LEFT|ES_MULTILINE|WS_VSCROLL,
    10,320,265,45,hMainWnd,(HMENU)Text_Box_Send,NULL,NULL);

    SetWindowLongPtr(hMainWnd,GWLP_USERDATA,(LONG_PTR)toSend);

    ShowWindow(hMainWnd, SW_SHOW); 
    //UpdateWindow(hMainWnd);

    return hMainWnd;

}

这是我程序的主要部分:

int WINAPI WinMain(HINSTANCE hlnstance, HINSTANCE hPrevInstance, LPSTR IpCmdLine, int 
nCmdShow) 
{
WNDCLASSEX wc; 
    wc.cbSize = sizeof(wc); 
    wc.style = CS_HREDRAW | CS_VREDRAW; 
    wc.lpfnWndProc = MyFunc; 
    wc.cbClsExtra = 0; 
    wc.cbWndExtra = 0; 
    wc.hInstance = hlnstance; 
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION); 
    wc.hCursor = LoadCursor(NULL, IDC_ARROW); 
    wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wc.lpszMenuName = NULL; 
    wc.lpszClassName = L"Class"; 
    wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
HWND toSend = createMainWindow(P2pSocket);

//some code

hThread = CreateThread(NULL, 0, ClientThread, 
            Message2, 0, &dwThreadId);

        if (hThread == NULL)
        {
            cout<<"Create thread filed";
            exit(10);
        }


    while (GetMessage(&msg, NULL, 0, 0)) { 

        TranslateMessage(&msg); 
        DispatchMessage(&msg);

    }

    return msg.wParam;   

当我在程序的主要部分调用函数 createMainWindow() 时 它可以正常工作，但是当我运行它时 我的线程(ClientThread)不起作用。我读过我应该只在主线程中创建窗口。是真的吗？如果是这样，那么从另一个 thead 调用此函数以在主线程中完成的最简单方法是什么？

---

谢谢大家。现在我知道问题所在，但我仍然坚持解决方案。 我的客户端线程代码是:

while(1){

    vector<HWND> AllHandlers;

    pair<string,string> Answer = Pointer->receiveMsgByUdp();

    if(!Pointer->isMyLocalAddress(Answer.first)){

        int type = messageUdpContentType(Answer.second);

        switch(type){

        case 0 :

            Pointer->sendMsgToIpUdp(Answer.first,"<?xml version='1.0'?><accepted/>");
            AllHandlers = getAllHandlersOfElementsOnWindowsByIdentityCode(Pointer->getAllHandlers(),List_Box);
            for(vector<HWND>::iterator j = AllHandlers.begin();j!=AllHandlers.end();j++)
                if(SendMessageA(*j, LB_FINDSTRINGEXACT, 0, (LPARAM)Answer.first.c_str())==LB_ERR)
                    SendMessageA(*j, LB_ADDSTRING, 0, (LPARAM)Answer.first.c_str());

            break;

        case 1 :
            AllHandlers = getAllHandlersOfElementsOnWindowsByIdentityCode(Pointer->getAllHandlers(),List_Box);
            for(vector<HWND>::iterator j = AllHandlers.begin();j!=AllHandlers.end();j++)
                if(SendMessageA(*j, LB_FINDSTRINGEXACT, 0, (LPARAM)Answer.first.c_str())==LB_ERR)
                    SendMessageA(*j, LB_ADDSTRING, 0, (LPARAM)Answer.first.c_str());

            break;

        case 2 :
            AllHandlers = getAllHandlersOfElementsOnWindowsByIdentityCode(Pointer->getAllHandlers(),List_Box);
            for(vector<HWND>::iterator j = AllHandlers.begin();j!=AllHandlers.end();j++)
                if((i = SendMessageA(*j, LB_FINDSTRINGEXACT, 0, (LPARAM)Answer.first.c_str()))!=LB_ERR)
                    SendMessageA(*j,LB_DELETESTRING, 0, (LPARAM)Answer.first.c_str());

            break;

        case 3 :

            userReply = MessageBoxW(NULL, L"Принять приглашение на конференцию?",
                    L"", MB_YESNO | MB_ICONQUESTION); 
            if (userReply==IDYES){

                //todo: Проверка на создание встречи, в которой уже состоишь
                string nameOfConf = fetchNameOfInviteConf(Answer.second);
                Pointer->createConference(nameOfConf);
                HWND toSendTo = createMainWindow(Pointer);
                Pointer->setHandlerInfo(nameOfConf,toSendTo);               
                Pointer->addNewMemberToConference_ServerType(nameOfConf,Answer.first);
                string toSend = string("<?xml version='1.0'?><inviteAccepted>") + nameOfConf + string("</inviteAccepted>");
                Pointer->sendMsgToIpUdp(Answer.first,toSend);

            }
            break;

        case 4 :

            string nameOfConf = fetchNameOfInviteAcceptConf(Answer.second);

            toSend.clear();
            Participants.clear();
            Participants = Pointer->getCurrentParticipants(nameOfConf);
            toSend+="<?xml version='1.0'?>";
            toSend+="<conference>";
            toSend+="<nameOfConference>";
            toSend+=nameOfConf;
            toSend+="</nameOfConference>";
            for(vector<string>::iterator i = Participants.begin();i!=Participants.end();i++){
                toSend+="<participant>" + *i + "</participant>";
            }
            toSend+="</conference>";



            Pointer->addNewMemberToConference_ClientType(nameOfConf,Answer.first);

            Pointer->sendToIpTcp(Answer.first,toSend);

            break;

    }

函数 receiveMsgByUdp() 停止该线程，直到收到消息。我为缺乏知识而道歉，但我可以使用什么功能或其他东西来解决这个问题。我应该将我的方法 receiveMsgByUdp() 重写为异步的还是如何调用函数 createMainWindow() 在主线程上运行？关于最后一个变体:我如何在纯 winapi 中执行此操作，我找不到任何简单的示例。有人可以给代码片段。再次感谢)

Answer 1

您确实可以在主 UI 线程以外的线程中创建窗口。但是，这些窗口将与创建它们的线程具有亲和性，您将需要在创建窗口的每个线程中运行消息泵。

因此，虽然您可以按照您的要求做事，但 Win32 的真正设计目的是在一个进程中与同一个线程具有亲缘关系的所有窗口一起工作。创建多个 UI 线程实际上没有任何好处。你将成功地做的就是让你的生活异常复杂且不必要地复杂。