为什么上述代码中connect(button, &QPushButton::doubleClicked, this, &MainWindow::onButtonDoubleClicked);这里的 &QPushButton::doubleClicked报错

抱歉，我在之前的回答中犯了一个错误QPushButton没有提供`doubleClicked`信号，所以不能直接使用`doubleClicked`信号来连接槽函数。

要实现双击按钮进入其他界面的功能，可以使用`clicked`信号和计时器来模拟双击事件。下面是修正后的代码示例：

MainWindow.h：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QPushButton>
#include <QGridLayout>
#include <QTimer>

class MainWindow : public QMainWindow
{
    Q_OBJECT

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

private slots:
    void onButtonPressed();
    void onButtonReleased();
    void onButtonMouseMove();
    void onButtonClicked();

private:
    void setupUI();
    void setBackground();
    void createButtons();

    QWidget *centralWidget;
    QGridLayout *gridLayout;
    QTimer *longPressTimer;
    QPoint lastMousePos;
    bool isDoubleClick;
};

#endif // MAINWINDOW_H

MainWindow.cpp：

#include "mainwindow.h"
#include <QPalette>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    setupUI();
    setBackground();
    createButtons();

    longPressTimer = new QTimer(this);
    longPressTimer->setInterval(1000);
    connect(longPressTimer, &QTimer::timeout, this, &MainWindow::onButtonMouseMove);
}

MainWindow::~MainWindow()
{
}

void MainWindow::setupUI()
{
    centralWidget = new QWidget(this);
    gridLayout = new QGridLayout(centralWidget);
    setCentralWidget(centralWidget);
}

void MainWindow::setBackground()
{
    QPalette palette;
    palette.setBrush(this->backgroundRole(), QBrush(QImage("background.jpg")));
    this->setPalette(palette);
}

void MainWindow::createButtons()
{
    for (int i = 0; i < 7; i++) {
        QPushButton *button = new QPushButton(centralWidget);
        button->setIcon(QIcon("icon.png"));
        button->setIconSize(QSize(100, 100));
        button->setStyleSheet("background-color: transparent; border: none;");
        gridLayout->addWidget(button, i / 3, i % 3);

        connect(button, &QPushButton::pressed, this, &MainWindow::onButtonPressed);
        connect(button, &QPushButton::released, this, &MainWindow::onButtonReleased);
        connect(button, &QPushButton::clicked, this, &MainWindow::onButtonClicked);
    }
}

void MainWindow::onButtonPressed()
{
    QPushButton *button = qobject_cast<QPushButton*>(sender());
    lastMousePos = button->mapToGlobal(QPoint(0, 0));
    longPressTimer->start();
}

void MainWindow::onButtonReleased()
{
    if (!isDoubleClick) {
        longPressTimer->stop();
    }
}

void MainWindow::onButtonMouseMove()
{
    QPushButton *button = qobject_cast<QPushButton*>(sender());
    if (longPressTimer->isActive()) {
        QPoint currentMousePos = QCursor::pos();
        int dx = currentMousePos.x() - lastMousePos.x();
        int dy = currentMousePos.y() - lastMousePos.y();
        int newX = button->x() + dx;
        int newY = button->y() + dy;
        button->move(newX, newY);
        lastMousePos = currentMousePos;
    }
}

void MainWindow::onButtonClicked()
{
    QPushButton *button = qobject_cast<QPushButton*>(sender());
    if (longPressTimer->isActive()) {
        longPressTimer->stop();
        isDoubleClick = true;
        // 执行双击后进入其他界面的逻辑处理
    } else {
        isDoubleClick = false;
    }
}

这样，我们通过在`onButtonClicked`槽函数中设置一个标志位`isDoubleClick`来判断是否进行双击操作。在单击按钮时，如果计时器未启动，则将`isDoubleClick`设置为`false`，如果计时器已经启动，则停止计时器，并将`isDoubleClick`设置为`true`，以实现模拟双击事件。然后根据`isDoubleClick`的值来执行相应的双击后进入其他界面的逻辑处理。

希望这次能够帮助到您！如有其他问题，请随时提问。