Qt异常：empty character constant

Qt错误：empty character constant

先看错误代码

void Widget::timerUpdate(){    QTime time = QTime::currentTime();    //获取当前时间    QString text = time.toString("hh:mm");    //转换成字符串    if((time.second() % 2) == 0)        text[2]=' ';    ui->lcdNumber->display(text);}