Question

我是Qt开发的新手，正在开发启动TCP Server的Qt DLL。当我从另一个应用程序调用dll时，它不会收到任何新的连接套接字。如果我做错了一步，请指导我。

Server.h

extern "C" SERVERSHARED_EXPORT void CallServer();
class SERVERSHARED_EXPORT Server :  public QObject
{
    Q_OBJECT
public:
    Server();
    void CallServer();
    void CallServer1();

    QTcpServer *server;
    QTcpSocket *socket ;
signals:
public slots:
    void myConnection();
    void closingClient();
};

Server.cpp

  Server::Server()
{

}

void CallServer()
{
    Server server_Obj;
    server_Obj.CallServer1();
    while (true)
        ::sleep(1000);
}

void Server::CallServer1()
{
    server = new QTcpServer(this);
    connect(server, SIGNAL(newConnection()),this, SLOT(myConnection()));

    QHostAddress hostadd(ServerIP);

    qDebug() << ServerIP;
    qDebug() << Port;

    if(!server->listen(hostadd,Port.toInt()))        qDebug() << "\nWeb server     could not start";
    else                                             qDebug() <<"\nWeb server is waiting for a connection";

}

void Server::myConnection()
{
    qDebug() << "Detected Connection";
    QByteArray Rdata;
    socket = server->nextPendingConnection();

    qDebug() << "Wait for connect = " << socket->waitForConnected();

    while (socket->waitForReadyRead(10))
    {
        while(socket->bytesAvailable() > 0)
        {
            Rdata.append(socket->readAll());
        }
    }

    qDebug() << "Final Testing is size = " << Rdata.size();
    qDebug() << "Final Testing is" << Rdata;
}

.pro文件

QT       += core
QT       += network
QT      += widgets
QT       -= gui

TARGET = Server
TEMPLATE = lib

DEFINES += SERVER_LIBRARY

SOURCES += server.cpp 
HEADERS += server.h\
        server_global.h

另一个应用程序：

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);


    QLibrary library("Server.dll");
     if (!library.load())
        qDebug() << library.errorString();
     if (library.load())
         qDebug() << "library loaded";

     typedef int(*pf)(void);
     pf cwf = (pf)library.resolve("CallServer");
     if (cwf) {
      int x = cwf();
     } else {
      qDebug() << "Could not show widget from the loaded library";
     }

     qDebug() << "After call";

    return a.exec();
}

Answer 1

看起来它没有工作，因为你在异步（信号/插槽）方式中使用QTcpSocket（你的服务器类）没有事件循环 - 所以它不起作用。您应该以阻塞方式添加事件循环或使用套接字。有关详细信息，请查看 - http://doc.qt.io/qt-5/qtnetwork-blockingfortuneclient-example.html

如何从Qt中的另一个应用程序调用DLL

1 个答案: