Question

我想在我的MFC DLL中使用QT XML。我想使用它来使QXmlQuery选择我的xml文件中的节点。我创建了这样的标题。问题是如果我在for循环中调用select方法，程序会因为访问冲突而在第二次迭代中崩溃。问题出现是因为QCoreApplication没有正确退出。我该怎么办

#define NOMINMAX 

#pragma once
#include <windows.h>
#include <vector>
#include <iostream>
#include <string>

#include <QtCore/QObject>
#include <QtCore/QFile>
#include <QtXml/QDomDocument>
#include <QtXml/QDomElement>
#include <QtCore/QCoreApplication>
#include <QtXmlPatterns/QXmlQuery>
#include <QtCore/QBuffer>
#include <QtXmlPatterns/QXmlSerializer>
#include <QtCore/QTimer>
#include <QtWidgets/QApplication>
#include "Utilities.h"
#include "GeneralConfigs.h"

namespace DBMS_ENGINE{
class SelectEngine: public QObject
{
    Q_OBJECT
public:
    explicit SelectEngine();
    DWORD DBMS_ENGINE::SelectEngine::Select(QString tablePath){
        DWORD result=0;
        using namespace std;
        int argc=1;
        char *argv[]={"1","2"};
        QTimer t;
        a=new QCoreApplication(argc,argv);
        connect(a,SIGNAL(a->aboutToQuit()),a,SLOT(quit()));
        QFile sourceDocument;
        sourceDocument.setFileName(tablePath);
        sourceDocument.open(QIODevice::ReadOnly);
        QByteArray outArray;
        QBuffer buffer(&outArray);
        buffer.open(QIODevice::ReadWrite);
        QXmlQuery query;
        query.bindVariable("inputDocument", &sourceDocument);
        QString QueryString;
        QueryString=QString("declare variable $inputDocument external; \n             doc($inputDocument)/root/key");
        query.setQuery(QueryString);
        QString result1;
        query.evaluateTo(&result1);

    }//end of methos
    private:
    QCoreApplication *a;
    private slots:
        void quit(){
            QCoreApplication::quit();
            a->exit();
            qApp->quit();
            QCoreApplication::exit();

        }//end of method
};//end of class
}//end of namespace

QCoreApplication无法正确退出

0 个答案: