QObject::connect 在运行时失败，同时将线程的完成信号链接到映射器的 delateLater-slot

Question

我在我的项目中使用 C++ 和 Qt4.5.2（目标系统的要求）。需要一个附加 arguments/parameter 提供的工作线程，所以我做了以下操作（简而言之，删除错误 handling/output）：

bool _bRetVal = false;
COpgThread* _pParseThread = new COpgThread(); // COpgThread is subclassed from QThread to access the protected msleep-function
COpgWorker* _pParseWorker = new COpgWorker(); // COpgWorker is subclassed from QObject to provide: slots (process) and signals (finished, progress, error) for a COpgThread-instance
QSignalMapper* _pParseMapper = new QSignalMapper();
COpgParam _pParseParam = new COpgParam(m_sParseFile, m_sRegExpFile); // COpgParam is subclassed from QObject to handle user data for mapping

_pParseWorker->moveToThread(_pParseThread);
//#1 hookup error-signal from worker to errorParsing-function in this object
_bRetVal = QObject::connect(_pParseWorker, SIGNAL(error(int const)), this, SLOT(errorParsing(int const)));

//#2..3 hookup thread's started-signal to process-slot in the worker (via signal mapper for parameters/arguments)
_bRetVal = QObject::connect(_pParseThread, SIGNAL(started()), _pParseMapper, SLOT(map()));
_pParseMapper->setMapping(_pParseThread, _pParseParam);
_bRetVal = QObject::connect(_pParseMapper, SIGNAL(mapped(QObject*)), _pParseWorker, SLOT(process(QObject*)));

//#4 hookup progress-signal from worker to progessParsing-function in this object    
_bRetVal = QObject::connect(_pParseWorker, SIGNAL(progress(int const)), this, SLOT(progressParsing(int const)));

//#5 hookup finished-signal from worker to completedParsing-function in this object
_bRetVal = QObject::connect(_pParseWorker, SIGNAL(finished(int const)), this, SLOT(completedParsing(int const)));

//#6 when worker emits finished-signal, signal thread to quit (shutdown)
_bRetVal = QObject::connect(_pParseWorker, SIGNAL(finished(int const)), _pParseThread, SLOT(quit()));
//#7 when worker emits finished-signal, mark worker to be deleted
_bRetVal = QObject::connect(_pParseWorker, SIGNAL(finished(int const)), _pParseWorker, SLOT(deleteLater()));
//++++ this connect fails at runtime ++++
    //#8 when thread emits finished-signal, mark mapper to be deleted
    _bRetVal = QObject::connect(_pParseThread, SIGNAL(finished(int const)), _pParseMapper, SLOT(deleteLater()));
//+++++++++++++++++++++++++++++++++++++++
//#9 when thread emits finished-signal, mark thread to be deleted
_bRetVal = QObject::connect(_pParseThread, SIGNAL(finished(int const)), _pParseThread, SLOT(deleteLater()));
_pParseThread->start();

整个代码编译没有任何错误，但是第8个连接在运行时失败了。我想，当我创建 QSignalMapper 的实例时......它必须在某个时候或其他时候被删除。也许这是浪费的代码。我对 Qt 不是很熟悉。

有什么建议吗？

提前致谢。

Answer 1

but the 8th connect fails at runtime.

一条错误消息被打印到标准输出 - 它打印了什么？

顺便说一句：QProcess::finished() 信号是 SIGNAL(finished(int)) - 这可能是你的问题。

QObject::connect 在运行时失败，同时将线程的完成信号链接到映射器的 delateLater-slot

QObject::connect fails at runtime, while linking thread's finished-signal to mapper's delateLater-slot

c++

qt

slot

qt-signals

qsignalmapper