Hello。

Hello.

Util WP8.1有PhoneApplicationPage控件的SupportedOrientations属性。但在UWP中并不存在这样的财产。为了实现你想要的你应该改变 

Util WP8.1 there was SupportedOrientations property for PhoneApplicationPage control. But in UWP there doesnn't exist such property. For achieve what you want you should change 

DisplayInformation.AutoRotationPreferences

 protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            base.OnNavigatedTo(e);
            switch (AnalyticsInfo.VersionInfo.DeviceFamily)
            {
                case "Windows.Mobile":
                    DisplayInformation.AutoRotationPreferences = DisplayOrientations.Portrait;
                    break;
                case "Windows.Desktop":
                    DisplayInformation.AutoRotationPreferences = DisplayOrientations.Landscape;
                    break;
            }
        }