【QT常见错误】 --- 数字与字符相加时，数字并不会发生隐式转换

1. #include <QString>
2. 
3. QtWidgetsApplication1::QtWidgetsApplication1(QWidget *parent)
4.     : QMainWindow(parent)
5. {
6.     ui.setupUi(this);
7. 
8.  QString ret = "";
9.  QString ackSignal = "lines";
10.   int sigNum = 5;
11. 
12. 
13.   ret = "output:" + sigNum +  QString(" ") + ackSignal;
14.   ui.lineEdit->setText(ret);
15. 
16. }

ret = "output:" + QString::number(sigNum) + QString(" ") +  ackSignal;