(转）Qt使用connect函数时向slot传递参数

设想这样一种场景：共有5个button，button1~button5，点击button1时输出“button 1 clicked”，点击button2时输出“button 2 clicked”，该如何实现呢？ 
最粗暴的实现是写5个slot，然后将button与slot分别connect，但这明显会增加许多重复代码，不是一种好的实现。 
一种比较好的方式是使用QSignalMapper，它可以接收无参数的signal，然后重新发射出有参数的signal，这些参数的类型可以是int、QString、QWidget *或QObject *：

QSignalMapper *signalMapper = new QSignalMapper(this);

connect(button1, SIGNAL(triggered()), signalMapper, SLOT(map()));
connect(button2, SIGNAL(triggered()), signalMapper, SLOT(map()));
connect(button3, SIGNAL(triggered()), signalMapper, SLOT(map()));
connect(button4, SIGNAL(triggered()), signalMapper, SLOT(map()));
connect(button5, SIGNAL(triggered()), signalMapper, SLOT(map()));

signalMapper->setMapping(button1, 1);
signalMapper->setMapping(button2, 2);
signalMapper->setMapping(button3, 3);
signalMapper->setMapping(button4, 4);
signalMapper->setMapping(button5, 5);

connect(signalMapper, SIGNAL(mapped(int)), this, SLOT(printMsg(int)));

转自：https://blog.csdn.net/imred/article/details/72940365

参考：https://stackoverflow.com/questions/5153157/passing-an-argument-to-a-slot