在Qt开发过程中，有时候我们要显示一个有阴影的对话框，这时一般采用自定义实现，然而最近在开发时软件时，Win11上显示正常，Win10或其他Win11电脑显示不正常，存在兼容性问题吗？

下面是具体的源码

#ifndef POPUPPEPANEL_H
#define POPUPPEPANEL_H

#include <QWidget>


class QPushButton;


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

protected:
    void paintEvent(QPaintEvent *event) override;

private:
    void initView();


private:
    QPushButton *m_btnAi{nullptr};
    QPushButton *m_btnDoc{nullptr};
    QPushButton *m_btnLink{nullptr};
    QPushButton *m_btnExcel{nullptr};

};

#endif // POPUPPEPANEL_H

#include "popuppanel.h"
#include <QPainter>
#include <QVBoxLayout>
#include <QSpacerItem>
#include <QtMath>
#include <QApplication>
#include <QDateTime>
#include <QPushButton>
#include <QPainterPath>

#define PRINTTIME QDateTime::currentDateTime().toString("yyyy.MM.dd hh:mm:ss.zzz");


PopupPanel::PopupPanel(QWidget *parent) :
    QWidget(parent)
{
    setAttribute(Qt::WA_TranslucentBackground, true);
    initView();
}

void PopupPanel::paintEvent(QPaintEvent *event)
{
    Q_UNUSED(event);
    //绘制阴影
    QPainter painter(this);
    QPainterPath path;
    path.setFillRule(Qt::WindingFill);
    path.addRoundedRect(5, 5, this->width() - 5 * 2, this->height() - 5 * 2, 3, 3);
    painter.setRenderHint(QPainter::Antialiasing, true);
    painter.fillPath(path, QBrush(Qt::white));

    QColor color("#BBBBBB");
    for (int i = 0; i < 5; i++)
    {
        QPainterPath path;
        path.setFillRule(Qt::WindingFill);
        path.addRoundedRect(5 - i, 5 - i, this->width() - (5 - i) * 2, this->height() - (5 - i) * 2, 3 + i, 3 + i);
        color.setAlpha(80 - qSqrt(i) * 40);
        painter.setPen(color);
        painter.drawPath(path);
    }
}



void PopupPanel::initView()
{
    QVBoxLayout *vLayoutMain = new QVBoxLayout();
    vLayoutMain->setSpacing(12);//4
    vLayoutMain->setContentsMargins(5, 12, 5, 12);
    vLayoutMain->setObjectName(QString::fromUtf8("vLayoutMain"));

    QSize size(110, 28);
    m_btnAi = new QPushButton(this);
    m_btnAi->setMinimumSize(size);
    m_btnAi->setMaximumSize(size);

    m_btnDoc = new QPushButton(this);
    m_btnDoc->setMinimumSize(size);
    m_btnDoc->setMaximumSize(size);

    m_btnLink = new QPushButton(this);
    m_btnLink->setMinimumSize(size);
    m_btnLink->setMaximumSize(size);

    m_btnExcel = new QPushButton(this);
    m_btnExcel->setMinimumSize(size);
    m_btnExcel->setMaximumSize(size);

    vLayoutMain->addWidget(m_btnAi);
    vLayoutMain->addWidget(m_btnDoc);
    vLayoutMain->addWidget(m_btnLink);
    vLayoutMain->addWidget(m_btnExcel);
    this->setLayout(vLayoutMain);

    //灰底
    QString strButtonStyle = QString("QPushButton{background-color:transparent;border-radius:0px;"
                                "background-image: url(:/image/%1);background-origin:content;background-position:left;"
                                "background-repeat: no-repeat;text-align:center;padding-left:12px;border:none;}"
                                "QPushButton:hover{background-color:#F2F2F2;}"
                                "QPushButton:pressed{background-color:#D5E7FE;}"
                               );

    m_btnAi->setStyleSheet(strButtonStyle.arg("ai.png"));
    m_btnDoc->setStyleSheet(strButtonStyle.arg("ding_doc.png"));
    m_btnLink->setStyleSheet(strButtonStyle.arg("link.png"));
    m_btnExcel->setStyleSheet(strButtonStyle.arg("excel.png"));

    QFont font = qApp->font();
    font.setPixelSize(14);
    m_btnAi->setFont(font);
    m_btnDoc->setFont(font);
    m_btnLink->setFont(font);
    m_btnExcel->setFont(font);

    m_btnAi->setText("Ai");
    m_btnDoc->setText("Doc");
    m_btnLink->setText("Link");
    m_btnExcel->setText("Excel");
}

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>
#include "popuppanel.h"

QT_BEGIN_NAMESPACE
namespace Ui { class Dialog; }
QT_END_NAMESPACE

class Dialog : public QDialog
{
    Q_OBJECT

public:
    Dialog(QWidget *parent = nullptr);
    ~Dialog();
    void initData();

public slots:
    void slotShowDialog();

private:
    Ui::Dialog *ui;
    PopupPanel *m_popupPanel{nullptr};
};
#endif // DIALOG_H

#include "dialog.h"
#include "ui_dialog.h"
#include <QDebug>

Dialog::Dialog(QWidget *parent)
    : QDialog(parent)
    , ui(new Ui::Dialog)
{
    ui->setupUi(this);
    initData();
}

Dialog::~Dialog()
{
    delete ui;
}

void Dialog::initData()
{
    QString strButtonStyle = QString("QPushButton{background-color:transparent;border-radius:0px;"
                                "background-image: url(:/image/show_move_control_normal.png);background-origin:content;background-position:left;"
                                "background-repeat: no-repeat;text-align:left;padding-left:12px;border:none;}"
                                "QPushButton:hover{background-color:#F2F2F2;background-image: url(:/image/show_move_control_hover.png);}"
                                "QPushButton:pressed{background-color:#D5E7FE;background-image: url(:/image/show_move_control_normal.png);}"
                               );

    //显示阴影对话框
    m_popupPanel = new PopupPanel(this);
    m_popupPanel->setObjectName(QString("m_popupPanel"));
    m_popupPanel->setMaximumSize(QSize(120, 150));
    m_popupPanel->setMinimumSize(QSize(120, 150));
    m_popupPanel->setWindowFlags(Qt::FramelessWindowHint | Qt::Popup);
    m_popupPanel->hide();
    connect(ui->pushButton, SIGNAL(clicked()), this, SLOT(slotShowDialog()));
}

void Dialog::slotShowDialog()
{
    qDebug() << "slotShowDialog=============================" << ui->pushButton->pos();
    QPoint point = mapToGlobal(ui->pushButton->pos());
    qDebug() << "slotShowDialog======================point=======" << point;
    m_popupPanel->move(point.x() - 130, point.y() - 160);
    m_popupPanel->show();
    qDebug() << "slotShowDialog=============================" << m_popupPanel->pos();
}

#include "dialog.h"

#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QFont defaultFont = qApp->font();
    defaultFont.setFamily("Microsoft YaHei");
    qApp->setFont(defaultFont);
    Dialog w;
    w.show();
    return a.exec();
}

运行点击Button按钮

这是在Win11上显示的效果

这是在Win10上显示的效果，很明显示，右边和底部有黑色线

同样一份代码为什么不同系统有不同效果呢？

原来有的系统是默认带了这个阴影效果，得把它去掉，即设置属性时，多加一个Qt::NoDropShadowWindowHint

在Dialog::initData()函数里，把

m_popupPanel->setWindowFlags(Qt::FramelessWindowHint | Qt::Popup);

改成

m_popupPanel->setWindowFlags(Qt::FramelessWindowHint | Qt::NoDropShadowWindowHint | Qt::Popup);

运行效果如下：

 现在在Win10上没有黑边效果了