How can I simulate a DeviceLost event with Win2D?

Question

I have a CanvasControl in a UWP app and I've noticed when I leave my Surface alone for a while and it goes to sleep automatically, the CanvasControl no longer works after resuming. The previously drawn bitmap is now blank.

I tried to simulate Suspend/Resume in Visual Studio 2015, but that doesn't seem to cause a problem. It resumes fine.

I have a feeling it has to do with the CanvasDevice.DeviceLost event, and although I manage that with the CanvasControl.CreateResources event, I can't find a way to easily test it.

I tried the following:

// This throws an exception. Not allowed to do this.
myCanvas.Device.RaiseDeviceLost(); 

// and this doesn't report a device lost, but myCanvas becomes unusable.
myCanvas.Device.Dispose();

Is there a way to programmatically invoke a CanvasDevice.DeviceLost event? How can I fake it?

Answer 1

It's not possible to trigger a device lost event with an API, but there is a command line tool you can use:

DXCap.exe -forcetdr

The version of DXCap you need is part of the Graphics Tools for Windows 10 package, for Win10 build 10586 or later: https://msdn.microsoft.com/en-us/library/mt125501.aspx#InstallGraphicsTools

After installing the VSGD, you can find DXCap in the windows\system32 directory.

Unfortunately it looks like this option is not (yet) documented, but from the command line:

  -forcetdr          Don't capture or replay, but simply force a GPU Timeout
                     Detection and Recovery event, then exit.