Qt：setDefault切换焦点

约定不等于承诺〃 2023-01-12 11:44 159阅读 0赞

Widget::Widget(QWidget *parent)
        : QWidget(parent)
    {
        button = new QPushButton("OK");
        button->setDefault(true);  //默认按钮:当按下enter键时，会默认选中[点击]button
        button->setParent(this);
        connect(button, SIGNAL(clicked()), this, SLOT(slotButtonClicked()));
    }
    void Widget::slotButtonClicked()
    {
        static int i = 0;  //局部静态变量
        qDebug() << "slotButtonClicked" << i++;
    }

![172984839434f5e03ab4cc3f28bd36cd285.jpg][]

一般情况下，焦点在主窗口上，但是如果我们需要处理子窗口，需要设置

#include "widget.h"
    #include <QPainter>
    #include <QDebug>
    #include <QVBoxLayout>
    Widget::Widget(QWidget *parent)
        : QWidget(parent)
    {
        QVBoxLayout *layout = new QVBoxLayout(this);
        QPushButton *button2, *button3;
        button = new QPushButton("OK");
        layout->addWidget(button);
        layout->addWidget(button2 = new QPushButton("cancel"));
        layout->addWidget(button3 = new QPushButton("quit"));
        button->setDefault(true);  //默认按钮:当按下enter键时，会默认选中[点击]button
        button2->setDefault(true);   //根据上下箭头切换焦点[V]，默认焦点为第一个设置的setDefault
        button3->setDefault(true);
        connect(button, SIGNAL(clicked()), this, SLOT(slotButtonClicked()));
        connect(button2, SIGNAL(clicked()), this, SLOT(slotButtonClicked()));
        connect(button3, SIGNAL(clicked()), this, SLOT(slotButtonClicked()));
    }
    void Widget::slotButtonClicked()
    {
        QPushButton *button = (QPushButton *)sender();
        qDebug() << button->text();
    }

![d1944ac86979824ca035b54c9ad97034795.jpg][]

[172984839434f5e03ab4cc3f28bd36cd285.jpg]: /images/20221119/44c747b6cebc47f7aacd2023a335890d.png
[d1944ac86979824ca035b54c9ad97034795.jpg]: /images/20221119/c6383ed94ff34ba8ac45dcd152572730.png