如何释放线程中创建的QUdpSocket对象
很多时候需要在QThread的run中new一个QUdpSocket来收发数据.这时,这个socket对象的释放就成了一个麻烦的问题.
如果在thread的析构中直接delete这个socket对象,则会出现如下异常:
QSocketNotifier: socket notifiers cannot be disabled from another thread
ASSERT failure in QCoreApplication::sendEvent: “Cannot send events to objects owned by a different thread. Current thread 560cb8. Receiver ” (of type ‘QNativeSocketEngine’) was created in thread a617748″, file kernel/qcoreapplication.cpp, line 349Invalid parameter passed to C runtime function.Invalid parameter passed to C runtime function.
以下是解决方案:
1.在线程中定义一个线程释放的标识
2.在run()中用while来判断这个标识,以便于结束socket对象.
3.在thread的析构中,设定标识,并使用quit()和wait().
代码如下:
UdpSocketThread::UdpSocketThread(QObject *parent) :
QThread(parent){this->socket = 0;this->needStop = false;}
UdpSocketThread::~UdpSocketThread(){this->needStop = true;quit();wait();}
void UdpSocketThread::run(){socket = new QUdpSocket;connect(socket,SIGNAL(readyRead()),this,SLOT(readPendingDatagrams()));socket->bind(2234);exec();while(this->needStop){if(this->socket){delete this->socket;this->socket = 0;}break;}}
这个线程对象的释放比较有代表性,应该可以解决很多类似的问题.另外,方法可能还有其他的,这里只是举了一种而已.其实,问题的关键就是:线程中创建的对象就必须在线程中释放.
PS:
经shiroki的指正,其实QT有更好的机制来释放对象.那就是deleteLater(). 于是,事情就显得非常简单,请看代码:
UdpSocketThread::UdpSocketThread(QObject *parent) :
QThread(parent){socket = 0;}
UdpSocketThread::~UdpSocketThread(){this->socket->deleteLater();quit();wait();}
void UdpSocketThread::run(){socket = new QUdpSocket;connect(socket,SIGNAL(readyRead()),this,SLOT(readPendingDatagrams()));socket->bind(2234);exec();
}
本文转自：http://qt.csdn.net/articles.aspx?pointid=743&pointid2=7
