QT 5.0 QDebug compilation error

问题

I am having trouble compiling my code with QDebug, but i really need it.

#include <QCoreApplication>
#include <QtDebug>
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    QDebug() << "hello";
    return a.exec();
}

This is an example of the error i got on this simple test: no matching function for call to 'QDebug::QDebug()'

回答1:

Try this:

qDebug() << "hello";

回答2:

The problem here is that QDebug does not have a default constructor. QDebug() << "hello"; would work if it did have one.

These are the available constructors:

QDebug(QIODevice* device);
QDebug(QString* string);
QDebug(QtMsgType type);
// and the copy constructor of course.

duDE's answer gives you what you're looking for.

来源：https://stackoverflow.com/questions/15364070/qt-5-0-qdebug-compilation-error