1.普通消息框,无互动
QMessageBox::information(this, QString::fromLocal8Bit("警告"),QString::fromLocal8Bit("已经是第一张了!"));
2.确认框,确认/取消
QMessageBox::StandardButton box;
box = QMessageBox::question(this, "提示", "确实要删除吗?", QMessageBox::Yes|QMessageBox::No);
if(box==QMessageBox::No)return;