麻烦大家帮忙看下，为什么我的程序里时钟显示不变化，不能动态显示时间呢？
class MyMainWindow : public QWidget
{
public:
MyMainWindow();
private:
QLabel *c_label;
QLabel *d_label;
QLabel *t_label;
QLabel *n_label;
QLabel *c_line;
QLabel *d_line;
QLabel *t_line;
QLabel *n_line;
};
MyMainWindow::MyMainWindow()
{
setMinimumSize(320,240);
setMaximumSize(320,240);
QDate date=QDate::currentDate();
QTime time=QTime::currentTime();
QTimer *timer = new QTime(t_line);
c_label=new QLabel(this);
d_label=new QLabel(this);
t_label=new QLabel(this);
n_label=new QLabel(this);
c_label->setGeometry(40,20,60,40);
c_label->setText("class:");
c_label->setAlignment(Qt::AlignCenter);
c_label->setFont(QFont("Time",16));
d_label->setGeometry(40,70,60,40);
d_label->setText("data:");
d_label->setAlignment(Qt::AlignCenter);
d_label->setFont(QFont("Time",16));
t_label->setGeometry(40,120,60,40);
t_label->setText("time:");
t_label->setAlignment(Qt::AlignCenter);
t_label->setFont(QFont("Time",16));
n_label->setGeometry(40,170,60,40);
n_label->setText("num:");
n_label->setAlignment(Qt::AlignCenter);
n_label->setFont(QFont("Time",16));
c_line=new QLabel("4301",this);
d_line=new QLabel(date.toString(),this);
t_line=new QLabel(time.toString(),this);
n_line=new QLabel(this);
c_line->setGeometry(110,20,170,40);
c_line->setFont(QFont("Time",16));
d_line->setGeometry(110,70,170,40);
d_line->setFont(QFont("Time",16));
t_line->setGeometry(110,120,170,40);
t_line->setFont(QFont("Time",16));
t_line->setText(time.toString("hh:mm:ss"));
connect(timer,SIGNAL(timeout()),t_line,SLOT(update()));
timer->start(1000);
n_line->setGeometry(110,170,170,40);
n_line->setFont(QFont("Time",16));
};
int main(int argc, char **argv)
{
QApplication app(argc, argv);
MyMainWindow mymainwindow;
mymainwindow.show();
return app.exec();
};
