QT 发送signal但是无法到达SLOT函数，修改下程序就可以，望大牛解答为什么？

[童心童颜]

main函数部分代码如下：
Message_Handler * pMsgHandler = new Message_Handler();
QThread *pMsgHandlerThread = new QThread;
pMsgHandler->moveToThread(pMsgHandlerThread);
QObject::connect(pMsgHandlerThread, SIGNAL(started()), pMsgHandler, SLOT(handleMessage()));
pMsgHandlerThread->start(QThread::NormalPriority);

QObject::connect(pServerStatusGui, SIGNAL(signalSendClientSetupInitNetMsg()),pMsgHandler, SLOT(sendClientSetupInitNetMsg()),Qt::AutoConnection);


如果我发送signalSendClientSetupInitNetMsg（），那么QT无法找到slot sendClientSetupInitNetMsg（）


如果程序修改成
Message_Handler * pMsgHandler = new Message_Handler();
//QThread *pMsgHandlerThread = new QThread;
// pMsgHandler->moveToThread(pMsgHandlerThread);
// QObject::connect(pMsgHandlerThread, SIGNAL(started()), pMsgHandler, SLOT(handleMessage()));
// pMsgHandlerThread->start(QThread::NormalPriority);

QObject::connect(pServerStatusGui, SIGNAL(signalSendClientSetupInitNetMsg()),pMsgHandler, SLOT(sendClientSetupInitNetMsg()),Qt::AutoConnection);

如果我发送signalSendClientSetupInitNetMsg（），那么QT能够找到slot sendClientSetupInitNetMsg（）

想问下这个是怎么回事啊？

[Creator_莫言]

信号和槽也是基于事件循环的，如果你想给主线程给子线程发送信号，那子线程就要开启事件循环，否则是收不到的

[童心童颜]

了解了，多谢，线程的run函数被重写了，也是个无限循环，看来只能想想别的方法了。

[donwmufromdying]

子线程的run里放个exec();

[yaozhiyong110]

前一个因为你 pMsgHandler->moveToThread(pMsgHandlerThread); 对象属性移到子线程了 所以槽函数在子线程执行 因为你子线程没有event loop 所以没接收信号... ps: Qt 助手里去参考 Qt::ConnectionType

[yaozhiyong110]

Qt::AutoConnection (default) If the signal is emitted from a different thread than the receiving object, the signal is queued, behaving as Qt::QueuedConnection. Otherwise, the slot is invoked directly, behaving as Qt::DirectConnection. The type of connection is determined when the signal is emitted. Qt::QueuedConnection The slot is invoked when control returns to the event loop of the receiver's thread. The slot is executed in the receiver's thread.