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Qt: qobject_cast<QPushButton*>(sender()) 简化信号与槽的编写

Qt,qobject_cast,sender,简化,信号与槽2016-08-07

当你觉得写代码是一件重复性极高的工作时,这时你就应该考虑换个方式来实现了。

提高代码效率,减少代码量。

代码片:

void Widget::onClicked()
 {
    QPushButton* button = qobject_cast<QPushButton*>(sender());
    QRadioButton* radio = qobject_cast<QRadioButton*>(sender());

    if (button)
    {
        QString text = button->text();
        ui->label_2->setText(text);
    }
    else if(radio)
    {
        QString text = radio->text();
        ui->label_2->setText(text);
    }
 }

实例:

1、在Qt creator中拖拽出如下界面:


2、添加槽函数。

private slots:
    void onClicked();

3、添加信号与槽的关联。

    connect(ui->pushButton,SIGNAL(clicked(bool)),this,SLOT(onClicked()));
    connect(ui->pushButton_2,SIGNAL(clicked(bool)),this,SLOT(onClicked()));
    connect(ui->pushButton_3,SIGNAL(clicked(bool)),this,SLOT(onClicked()));
    connect(ui->pushButton_4,SIGNAL(clicked(bool)),this,SLOT(onClicked()));

    connect(ui->radioButton,SIGNAL(clicked(bool)),SLOT(onClicked()));
    connect(ui->radioButton_2,SIGNAL(clicked(bool)),SLOT(onClicked()));
    connect(ui->radioButton_3,SIGNAL(clicked(bool)),SLOT(onClicked()));
    connect(ui->radioButton_4,SIGNAL(clicked(bool)),SLOT(onClicked()));

4、实现槽函数。

void Widget::onClicked()
 {
    QPushButton* button = qobject_cast<QPushButton*>(sender());
    QRadioButton* radio = qobject_cast<QRadioButton*>(sender());

    if (button)
    {
        QString text = button->text();
        ui->label_2->setText(text);
    }
    else if(radio)
    {
        QString text = radio->text();
        ui->label_2->setText(text);
    }
 }

5、运行截图:



当然了,这里我只是举个例子,在实际的应用中大家可以扩展其功能的。