Last Updated: 06 Jun 2016 13:21 by ADMIN
The thrown error is that the element that should be set as FocusedElement cannot be found.

Available in LIB version 2016.2.606, it will be also available in the 2016 R2 SP1 release.
Last Updated: 20 Jan 2020 07:21 by ADMIN
Release LIB 2020.1.120 (1/20/2020)



I've found a new bug regarding per-monitor DPI awareness in the latest WPF controls build (2020.1.115).

Applications start fine on the modern Windows 10 systems (1607 or later) but crash on previous Windows versions.

The conditions to reproduce:

  • The application is launched on Windows version older than Windows 10 1607/Windows Server 2016. I've reproduced it on Windows 8.1/Windows Server 2012 R2, but I suppose it also affects Windows 10 1507/1511, and probably Windows 8/Windows Server 2012.
  • Application manifest contains:
<dpiAware xmlns="">true/PM</dpiAware>

Here is the stack trace:

System.EntryPointNotFoundException: Unable to find an entry point named 'GetDpiForSystem' in DLL 'User32.dll'.

   at Telerik.Windows.Controls.InternalWindow.Standard.NativeMethods.GetDpiForSystem()

   at Telerik.Windows.Controls.InternalWindow.Standard.DpiHelper.GetSystemScaleFactor()

   at Telerik.Windows.Controls.InternalWindow.Standard.DpiHelper.CalculateScaleFactor(IntPtr hwnd)

   at Telerik.Windows.Controls.InternalWindow.Standard.DpiHelper.GetPerMonitorDPIAwareScaleFactor(IntPtr hwnd)

   at Telerik.Windows.Controls.InternalWindow.ChromelessWindowHelper.<Initialize>b__81_0(Object sender, EventArgs args)

   at System.Windows.Window.OnSourceInitialized(EventArgs e)

   at System.Windows.Window.CreateSourceWindow(Boolean duringShow)

   at System.Windows.Window.CreateSourceWindowDuringShow()

   at System.Windows.Window.SafeCreateWindowDuringShow()

   at System.Windows.Window.ShowHelper(Object booleanBox)

   at System.Windows.Window.Show()

   at Telerik.Windows.Controls.InternalWindow.WindowWithNoChromeWindowHost.Open(Boolean isModal)

   at Telerik.Windows.Controls.WindowBase.ShowWindow(Boolean isModal)

   at Telerik.Windows.Controls.RadWindow.Show()

   at TelerikWpfCrash.App.OnStartup(StartupEventArgs e) in C:\Users\fedarovich\source\repos\Test\TelerikWpfCrash\TelerikWpfCrash\App.xaml.cs:line 20

The issue happens because the code calls the WinAPI functions not available on these OS versions (for example, GetDpiForSystem, but maybe there are more). 

I've attached a small example to reproduce this issue. It is for .Net Core 3.1, but the same issue exists in .Net Framework too.

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