void Demo::on_pushButton_clicked(){
QGridLayout * mainLayout= new QGridLayout(ui->groupBox);
QLineEdit *tl; QPushButton *tb;
for(int i=0;i<3;i++)
{
tl=new QLineEdit(ui->groupBox);
QString str("防区%1");
tb=new QPushButton(str.arg(i),ui->groupBox);
// tb=new QPushButton(tr("防区%1").arg(i),ui->groupBox);
//可以在此连接button的事件处理信号槽
------这个地方怎么给每个组件添加信号和槽呢?
mainLayout->addWidget(tl, i, 0);
mainLayout->addWidget(tb, i, 1);
}
ui->groupBox->setLayout(mainLayout);}