Qt的qDebug使用小结

 int num = 20;
 char str[20]="hello world";
 qDebug("如果只写在括号里，是不需要QDebug头文件的 %d %s", num, str);

DEFINES += QT_NO_DEBUG_OUTPUT

#include <QDebug>
class Student
{
public:
    Student(const QString& nm){name = nm;}
    QString getName() const{return name;}
private:
    QString name;
};
QDebug operator<<(QDebug debug, const Student &c)
{
    debug << c.getName();
    return debug;
}
int main(int argc, char *argv[])
{
    Student student("John");
    qDebug() << student;
}

qDebug()<<"Mc info:"<<info.m_id<<info.r_id<<info.display_type<<info.topic<<info.name<<info.sname;

qDebug()<<"Mc info:"<<info;

#include <QDebug>
class Info
{
public:
    QString m_id;
    QString r_id;
    QString display_type;
    QString topic;
    QString name;
    QString sname;
    friend QDebug& operator<<(QDebug out, const Info& info)
    {
        out <<info.m_id<<info.r_id<<info.display_type<<info.topic<<info.name<<info.sname;
        return out;
    }
};