Qt - 获取屏幕分辨率

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原文链接： https://blog.csdn.net/qq_39453936/article/details/120665562

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获取多个显示屏幕的分辨率

• 获取屏幕缩放后的逻辑分辨率

  BOOL CALLBACK EnumMonitor(HMONITOR handle, HDC hdc, LPRECT rect, LPARAM param) {
         
      std::vector<MONITORINFO> *list = (std::vector<MONITORINFO>*)param;
      MONITORINFO mi;
      mi.cbSize = sizeof(mi);
      GetMonitorInfo(handle, &mi);
      qebug()<<"is MONITORINFOF_PRIMARY:" << mi.dwFlags;
      list->push_back(mi);
      return true;
  }
  
  int main(int argc, char *argv[])
  {
         
  	int numbers = GetSystemMetrics(SM_CMONITORS);
  	std::vector<MONITORINFO> monitor_list;
  	EnumDisplayMonitors(NULL, NULL, EnumMonitor, (LPARAM)&monitor_list);
  	for (size_t i = 0; i < monitor_list.size(); ++i) {
         
  	    qebug()<<"width:"<<(monitor_list[i].rcMonitor.right - monitor_list[i].rcMonitor.left);
  	    qebug()<<"height:"<<(monitor_list[i].rcMonitor.bottom - monitor_list[i].rcMonitor.top);
  	}
  }
  

• 获取当前屏幕的物理分辨率

  RECT GetScreenRect(int screen) {
         
      DISPLAY_DEVICEW device;
      device.cb = sizeof(device);
      BOOL result = EnumDisplayDevicesW(NULL, screen, &device, 0);
  
      DEVMODEW device_mode;
      device_mode.dmSize = sizeof(device_mode);
      device_mode.dmDriverExtra = 0;
      result = EnumDisplaySettingsExW(device.DeviceName, ENUM_CURRENT_SETTINGS, &device_mode, 0);
  
      int x = device_mode.dmPosition.x;
      int y = device_mode.dmPosition.y;
      int width = device_mode.dmPelsWidth;
      int height = device_mode.dmPelsHeight;
  
      return {
          x, y, x + width, y + height };
  }
  
  int main(int argc, char *argv[])
  {
         
  	int numbers = GetSystemMetrics(SM_CMONITORS);
  	for (int i = 0; i < numbers; ++i) {
         
          auto size = GetScreenRect(i);
          qebug()<<"width:"<<(size.right - size.left);
          qebug()<<"height:"<<(size.bottom - size.top);
  	}
  }
  

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获取主屏幕分辨率

注意：需要在QApplication构造后调用

//获取屏幕缩放后的逻辑分辨率，也可以通过GetSystemMetrics(SM_CXSCREEN);GetSystemMetrics(SM_CYSCREEN) 获取
 	auto hMonitor = MonitorFromWindow(GetDesktopWindow(), MONITOR_DEFAULTTONEAREST);
    MONITORINFOEX miex;
    miex.cbSize = sizeof(miex);
    GetMonitorInfo(hMonitor, &miex);
    qreal cxLogical = (miex.rcMonitor.right - miex.rcMonitor.left);
    qreal cyLogical = (miex.rcMonitor.bottom - miex.rcMonitor.top);

// 获取当前屏幕的物理分辨率
    DEVMODE dm;
    dm.dmSize = sizeof(dm);
    dm.dmDriverExtra = 0;
    EnumDisplaySettings(miex.szDevice, ENUM_CURRENT_SETTINGS, &dm);
    qreal cxPhysical = dm.dmPelsWidth;
    qreal cyPhysical = dm.dmPelsHeight;

//获取缩放比例
    qreal xdpi = cxPhysical/cxLogical;
    qreal ydpi = cyPhysical/cyLogical;
    qreal dpi = (xdpi+ydpi)/2;

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Qt获取多个屏幕分辨率

//获取可用桌面大小  
QRect deskRect =  QApplication::desktop()->availableGeometry();  
//获取设备屏幕大小  
QRect screenRect =  QApplication::desktop()->screenGeometry();  
//获取系统设置的屏幕个数（屏幕拷贝方式该值为1，只有设置成扩展时才返回多个）  
int g_nScreenCount = desktopWidget->screenCount();  

//获取该主机显示器列表（屏幕拷贝方式该值为1，只有设置成扩展时才返回多个）  
QList<QScreen *> list_screen = QGuiApplication::screens();
for (int i = 0; i < list_screen.size(); i++)
{
     
   QRect rect = list_screen.at(i)->geometry();
   int desktop_width = rect.width();
   int desktop_height = rect.height();
   qDebug() << desktop_width <<desktop_height;
}

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参考文章：https://blog.csdn.net/yp18792574062/article/details/88365965
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