通过QScreen来测试dpi变化事件通过

Qss.cpp

@@ -161,6 +161,10 @@ void QssTtitleBar::mouseMoveEvent( QMouseEvent * ev )
     QPoint globalPt = ev->globalPos();
     QPoint movePt = globalPt - m_pressedPos;//FrameglobalPos
     parentWidget()->move(movePt);//globalPos
+    QssMainWindow *parent = static_cast<QssMainWindow*>(parentWidget());
+    if(nullptr != parent){
+        parent->DetectDpiChange();
+    }
     return ;
 }
 
@@ -242,10 +246,15 @@ void QssMainWindow::OnMaxOrRestore(bool max)
     }
 }
 
+void QssMainWindow::DpiChange(qreal dpi)
+{
+    qDebug()<<"change dpi of QssMainWindow"<<dpi;
+
+}
+
 
 QssMainWindow::QssMainWindow(QWidget *parent/* = 0*/, Qt::WindowFlags flags/* = 0*/,float scale)
 : QMainWindow(parent, flags),
-  ICallDPIChanged(),
   m_mousePressedInBoundy(false),
   m_bLeftPress(false)
 {
@@ -288,6 +297,14 @@ QssMainWindow::QssMainWindow(QWidget *parent/* = 0*/, Qt::WindowFlags flags/* =
     mShadowMask->setStyleSheet("QWidget{background-color:rgba(1,1,1,0.3);}");
     mShadowMask->hide();
 
+    int screenNum =  qApp->desktop()->screenNumber(this);
+    qDebug()<<"current screen number is "<<screenNum;
+    mCurrentScreen = qApp->screens().at(screenNum);
+    if(nullptr != mCurrentScreen){
+        connect(mCurrentScreen,
+                SIGNAL(physicalDotsPerInchChanged(qreal)),
+                this,SLOT(DpiChange(qreal)));
+    }
     return;
 }
 
@@ -301,6 +318,17 @@ QWidget *QssMainWindow::TitleBar()
     return m_titleBar;
 }
 
+void QssMainWindow::DetectDpiChange()
+{
+    int screenNum =  qApp->desktop()->screenNumber(this);
+    auto currentScreen = qApp->screens().at(screenNum);
+
+    if(currentScreen != mCurrentScreen){
+        qDebug()<<"dpi change,reason screen changed";
+        mCurrentScreen = currentScreen;
+    }
+}
+
 void QssMainWindow::ShowMask()
 {
     mShadowMask->setGeometry(0, 0, this->width(),this->height());    //遮罩窗口位置
@@ -586,7 +614,6 @@ bool QssMainWindow::eventFilter(QObject * obj, QEvent * ev){
     }
     else if (obj == m_titleBar)
     {
-//        QCoreApplication::sendEvent(this,new QEvent(QEvent::Type::Resize));
         if (ev->type() == QEvent::Enter)
         {
             m_left = false;
@@ -632,26 +659,6 @@ bool QssMainWindow::eventFilter(QObject * obj, QEvent * ev){
 }
 
 
-bool QssMainWindow::nativeEvent(const QByteArray &eventType, void *message, long *result)
-{
-
-    MSG* pMsg = reinterpret_cast<MSG*>(message);
-    switch (pMsg->message)
-    {
-        case WM_DPICHANGED:
-        {
-            qDebug()<<"DPI CHANGED";
-            /*DWORD dpi = LOWORD(pMsg->wParam);
-            //WId id = WINDOW_WINID;
-            //if (DPIHelper()->DPIChanged(dpi, id))
-            {
-                ScaleChanged(DPIHelper()->GetDPIScale(id));
-                RefrushSheet(this, id);
-            }*/
-        }
-    }
-    return false;
-}
 
 void QssMainWindow::ScaleChanged(float scale)
 {
@@ -1801,25 +1808,16 @@ void QSSASyncProcess::Run(void *)
 uint16_t CurrentDPI(QWidget* widget,int monitor)
 {
     float dpi = 1.0;
-    int screenNum =  qApp->desktop()->screenNumber(widget); //this 表示当前的窗口 QWidget类型
+    int screenNum =  qApp->desktop()->screenNumber(widget);
+    qDebug()<<"current screen number is "<<screenNum;
     auto screens = qApp->screens();
-    qDebug()<<"screenNum"<<screenNum<<screens.size();
-    if(screenNum >= 0){
-        QScreen* screen = qApp->screens().at(monitor);
-        dpi = screen->physicalDotsPerInch();
-        qDebug()<<screen->physicalDotsPerInch()<<screen->physicalDotsPerInchX()<<screen->physicalDotsPerInchY();
-        qDebug()<<screen->logicalDotsPerInch()<<screen->logicalDotsPerInchX()<<screen->logicalDotsPerInchY();
+    for(int i = 0;i < screens.size();i++){
+        if(screenNum >= 0){
+            QScreen* screen = qApp->screens().at(i);
+            dpi = screen->physicalDotsPerInch();
+            qDebug()<<screen->physicalDotsPerInch()<<screen->physicalDotsPerInchX()<<screen->physicalDotsPerInchY();
+            qDebug()<<screen->logicalDotsPerInch()<<screen->logicalDotsPerInchX()<<screen->logicalDotsPerInchY();
+        }
     }
-
-    int currentScreenWidth = QApplication::desktop()->width();
-    int currentScreenHeight = QApplication::desktop()->height();
-//或者
-    QDesktopWidget* desktopWidget = QApplication::desktop();
-    //获取可用桌面大小
-    QRect deskRect = desktopWidget->availableGeometry();
-    //获取设备屏幕大小
-    QRect screenRect = desktopWidget->screenGeometry();
-    auto screenX = screenRect.width();
-    auto screenY = screenRect.height();
     return dpi;
 }