Qt信号/槽和C++λ表达式

class MyWidget : public QWidget {
    Q_OBJECT

public:
    MyWidget(QWidget *parent = nullptr);

signals:
    void mySignal();

public slots:
    void mySlot();
};

MyWidget::MyWidget(QWidget *parent) : QWidget(parent) {
    connect(this, &MyWidget::mySignal, this, &MyWidget::mySlot);
}

#include <QApplication>
#include <QPushButton>
#include <QMessageBox>

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);

    QPushButton button("Click Me");

    // 使用 lambda 表达式连接信号和槽
    QObject::connect(&button, &QPushButton::clicked, [&]() {
        QMessageBox::information(nullptr, "Lambda", "Button clicked!");
    });

    button.show();
    return app.exec();
}

#include <QApplication>
#include <QPushButton>
#include <QLineEdit>
#include <QVBoxLayout>
#include <QWidget>

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);

    QWidget window;
    QVBoxLayout layout(&window);

    QLineEdit lineEdit;
    QPushButton button("Show Text");

    layout.addWidget(&lineEdit);
    layout.addWidget(&button);

    // 捕获 lineEdit 变量
    QObject::connect(&button, &QPushButton::clicked, [&]() {
        QString text = lineEdit.text();
        QMessageBox::information(nullptr, "Lambda", "Text: " + text);
    });

    window.show();
    return app.exec();
}