dbzhang800:Qt4的表现是正常的,Qt5应该要编译报错的,但是很不幸,官方做了各种尝试,想让Qt5报错(也就是要禁止楼主在Qt5这么使用信号),但是都失败了。In Qt 5 we had to change signals from protected to public. This is unfortunate since this mean anyone can emit the signals. .. (2018-12-14 20:44)