廢話不多說，直接上代碼：
構造函數：

MyWidget(QWidget *parent = nullptr) {// 設置窗口屬性：支持透明背景setAttribute(Qt::WA_TranslucentBackground);// 移除窗口邊框setWindowFlags(Qt::FramelessWindowHint);}

closeEvent函數：

    void closeEvent(QCloseEvent *event) override {if (!isClosing) {event->ignore();auto effect = new QGraphicsOpacityEffect(this);effect->setOpacity(1.0); // 設置初始透明度為完全不透明this->setGraphicsEffect(effect);auto timeLine = new QTimeLine(500, this); // 動畫時長1000msconnect(timeLine, &QTimeLine::valueChanged, this, [=](qreal value) {// 根據進度計算漸變參數//qDebug()<<"Value: "<<value;QLinearGradient gradient(0, this->height(), 0, 0);gradient.setColorAt(0, QColor(255,255,255, 0));   // 底部透明gradient.setColorAt(value, QColor(255,255,255, 0));   // 底部透明gradient.setColorAt(1, QColor(255,255,255, 255)); // 頂部不透明// 應用漸變遮罩并設置整體透明度effect->setOpacityMask(gradient);effect->setOpacity(1 - value);});connect(timeLine, &QTimeLine::finished, this, [this]() {isClosing = true;close(); // 動畫完成后關閉窗口});timeLine->start();} else {event->accept();}}

再來個槽函數綁定一下關閉窗口退出：

private slots:void on_pushButton_1_clicked(){QApplication::quit();}private:bool isClosing = false; // 標志位，控制是否正在關閉

效果如下：
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