QTcpSocket如何返回QString
QTcpSocket如何返回QString
提问于 2018-07-12 16:59:31
我有一个服务: GWT客户端调用QT QTcpSocket函数，向设备发出请求并获得响应(它不能是唯一的响应。我应该等他们所有的人)。
根据QT文档，我不能使用waitForReadyRead()函数，因为我使用的是Windows平台。
注意:此函数在Windows上可能会随机失败。如果您的软件将在Windows上运行，请考虑使用事件循环和readyRead()信号。http://doc.qt.io/qt-5/qabstractsocket.html#waitForReadyRead
我现在只有一个决定：
伪代码：
QString MainQTFunc() {
create new thread;
while (!thread.isStopped()) {
sleep(x);
}
return QString variable from thread to GWT client;
}
New Thread {
run() {
make a TcpRequest to the device...
}
boolean isStopped() {
if(we got the response!!!) {
return true;
}
}
}是这样做的最佳解决方案吗？我不明白如何在得到结果后简单地发送QString变量。难道真的不可能实现功能强大的QT吗？
现在我有(没有任何线程)：
// The function should to return QString to the GWT client
QString MainWindow::TcpConnect(QByteArray data) {
_pSocket = new QTcpSocket( this );
connect( _pSocket, SIGNAL(readyRead()), SLOT(readTcpData()) );
connect( _pSocket, SIGNAL(connected()), SLOT(connected()) );
connect( _pSocket, SIGNAL(disconnected()), SLOT(disconnected()) );
dataGlobal = data;
_pSocket->connectToHost("IP", port);
//waiting here for all responses and sendinig the last response
return responseHexGlobal;
}
void MainWindow::connected() {
qDebug() << "connected. " << QDateTime::currentDateTime();
_pSocket->write( dataGlobal );
}
void MainWindow::disconnected() {
qDebug() << "disconnected. " << QDateTime::currentDateTime();
}
void MainWindow::readTcpData()
{
QByteArray data = _pSocket->readAll();
QByteArray as_hex_string = data.toHex();
QString response = QString(as_hex_string);
if(some condition here...) {
responseHexGlobal = response;
_pSocket->disconnectFromHost();
}
} 回答 1
Stack Overflow用户
发布于 2018-07-26 09:03:56
这是我找到的最好的解决方案。它能用，但我不喜欢它
QString JSPrinter::connectTcp(QByteArray data) {
QTimer timer;
timer.setSingleShot(true);
QEventLoop loop;
_pSocket = new QTcpSocket( this ); // <-- needs to be a member variable: QTcpSocket * _pSocket;
connect( _pSocket, SIGNAL(readyRead()), SLOT(readTcpData()) );
connect( _pSocket, SIGNAL(connected()), SLOT(connected()) );
connect( _pSocket, SIGNAL(disconnected()), SLOT(disconnected()) );
connect( &timer, SIGNAL(timeout()), &loop, SLOT(quit()) );
loop.connect( this, SIGNAL(exitLoop()), SLOT(quit()) );
dataGlobal = data;
_pSocket->connectToHost(ip_, port_);
timer.start(75000);
loop.exec();
if(timer.isActive())
logger()->info("ok");
else
logger()->info("timeout");
return responseHexGlobal;
}
void JSPrinter::connected() {
qDebug() << "connected. " << QDateTime::currentDateTime();
_pSocket->write( dataGlobal );
}
void JSPrinter::disconnected() {
qDebug() << "disconnected. " << QDateTime::currentDateTime();
}
void JSPrinter::readTcpData() {
QByteArray data = _pSocket->readAll();
QByteArray as_hex_string = data.toHex();
std::string stdString(as_hex_string.constData(), as_hex_string.length());
qDebug() << "readTcpData response " << QDateTime::currentDateTime() << QString::fromStdString(stdString);
// doing something...
if(condition) {
responseHexGlobal = received;
qDebug() << "responseHexGlobal " << responseHexGlobal;
emit exitLoop();
_pSocket->disconnectFromHost();
} else {
emit exitLoop();
_pSocket->disconnectFromHost();
return;
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/51301353
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