DisplayInformation exception in WinUI3 preview4

[arivoir]

Since preview 4 the following code is throwing an exception

Windows.Graphics.Display.DisplayInformation.GetForCurrentView().RawPixelsPerViewPixel

Element not found. (0x80070490)
at WinRT.ExceptionHelpers.ThrowExceptionForHR(Int32 hr)

Is this a bug, or is there any way round?

[marb2000]

DisplayInformation.GetForCurrentView() is no longer supported in WinUI 3 in Desktop. You should use XamlRoot's RasterizationScale

[maxkatz6]

Will those unsupported classes removed from public API?

[marb2000]

Some APIs belong to WinUI and Reunion projects (e.g. Microsoft.*), others belong to the UWP Platform that ships with the Windows 10 OS. For example, the Windows.Graphics.Display.DisplayInformation works well in UWP apps. We can't remove these APIs. But we do plan to remove the WinUI APIs that don't work from the supported versions (e.g. Reunion 0.5). For example, given Reunion 0.5 will support only WinUI 3 in Desktop, we should remove the Dispatcher,CoreDispatcher, Current, and CoreWindow properties from the Microsoft.UI.Xaml.Window class. Does this make sense to you?

[sigmarsson]

@marb2000 How shall I access the current view if DisplayInformation.GetForCurrentView() is deprecated ?

[BorzillaR]

@marb2000, is there suggested replacement for DisplayInformation.ScreenHeightInRawPixels property? I did not find it in this document.

[krschau]

@sigmarsson The answer depends on what you needed the current view for. For the TitleBar in your example, does this help?
https://docs.microsoft.com/en-us/windows/winui/api/microsoft.ui.xaml.window.settitlebar?view=winui-3.0

More generally, hopefully the answer can be found in this list:
https://docs.microsoft.com/en-us/windows/apps/desktop/modernize/desktop-to-uwp-supported-api#classes-with-getforcurrentview-methods

If you're having concerns and this doesn't address them, please open a new issue.

[krschau]

@BorzillaR If you want to get monitor info to replace ScreenHeightInRawPixels, you can try using MonitorFromWindow to get the HMONITOR and plug that into GetMonitorInfoW.

If this doesn't work for what you need, please open a new issue and we'll get it sorted out.