qt 子窗口某函数发送信号到父窗口，使父窗口关闭子窗口，c++示例

以下是一个简单的示例，演示如何在Qt中实现子窗口某函数向父窗口发送信号，使父窗口关闭子窗口：

MyChildWindow.h:

#ifndef MYCHILDWINDOW_H
#define MYCHILDWINDOW_H

#include <QWidget>

class QPushButton;

class MyChildWindow : public QWidget
{
    Q_OBJECT
public:
    explicit MyChildWindow(QWidget *parent = nullptr);

signals:
    void closeWindow();

private slots:
    void closeWindowButtonClicked();

private:
    QPushButton *closeWindowButton;
};

#endif // MYCHILDWINDOW_H

MyChildWindow.cpp:

#include "MyChildWindow.h"
#include <QPushButton>
#include <QVBoxLayout>

MyChildWindow::MyChildWindow(QWidget *parent) : QWidget(parent)
{
    closeWindowButton = new QPushButton("Close Window", this);
    connect(closeWindowButton, &QPushButton::clicked, this, &MyChildWindow::closeWindowButtonClicked);

    QVBoxLayout *layout = new QVBoxLayout(this);
    layout->addWidget(closeWindowButton);
    setLayout(layout);
}

void MyChildWindow::closeWindowButtonClicked()
{
    emit closeWindow();
}

MainWindow.h:

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

class MyChildWindow;

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void openChildWindow();
    void closeChildWindow();

private:
    MyChildWindow *childWindow;
};

#endif // MAINWINDOW_H

MainWindow.cpp:

#include "MainWindow.h"
#include "MyChildWindow.h"
#include <QVBoxLayout>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    childWindow = nullptr;

    QPushButton *openButton = new QPushButton("Open Child Window", this);
    connect(openButton, &QPushButton::clicked, this, &MainWindow::openChildWindow);

    QVBoxLayout *layout = new QVBoxLayout(this);
    layout->addWidget(openButton);
    QWidget *centralWidget = new QWidget(this);
    centralWidget->setLayout(layout);
    setCentralWidget(centralWidget);
}

MainWindow::~MainWindow()
{
    if (childWindow != nullptr)
    {
        delete childWindow;
    }
}

void MainWindow::openChildWindow()
{
    if (childWindow == nullptr)
    {
        childWindow = new MyChildWindow(this);
        connect(childWindow, &MyChildWindow::closeWindow, this, &MainWindow::closeChildWindow);
        childWindow->show();
    }
}

void MainWindow::closeChildWindow()
{
    if (childWindow != nullptr)
    {
        childWindow->close();
        delete childWindow;
        childWindow = nullptr;
    }
}

在这个示例中，`MyChildWindow`类表示子窗口，它包含一个名为"closeWindowButton"的按钮，当用户单击该按钮时，它会触发一个名为"closeWindow"的信号。该信号被定义为`void closeWindow()`，它表示要关闭窗口。

`MainWindow`类表示父窗口，它包含一个名为"openButton"的按钮，当用户单击该按钮时，它将创建`MyChildWindow`对象，并将其连接到该对象的"closeWindow"信号的`closeChildWindow`槽函数。当子窗口触发"closeWindow"信号时，`MainWindow`的`closeChildWindow`槽函数将被调用，它将关闭子窗口并删除子窗口对象。