信号与槽练习

通过信号与槽练习，实现按回车键进入下一文本框编辑

void Widget::next()

{

QLineEdit *lineEdit = (QLineEdit *)sender();

if (lineEdit == ui->lineEdit1) {

ui->lineEdit2->setFocus();

} else if (lineEdit == ui->lineEdit2) {

ui->lineEdit3->setFocus();

} else if (lineEdit == ui->lineEdit3) {

ui->lineEdit1->setFocus();

}

}