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I am attempting to "blurr" a windows 10 user control when an adorner is placed over it.

More exactly, I have a datagrid control in a wpf user window. When a cell in the datagrid is selected, an editing adorner is created over the datagrid control.

I have a WindowsFormsHost nested inside a WPF ScrollViewer, for some reason, after applying clipping it seems that the WIndowsFormsHost is not filling up all of the available spaces, ie: the control has been overclipped.

Here's how it looks like-- note that there are a lot of white space, which really should be filled with blue color.

Here's my code in totality:

I am trying to make a taskbar app with WPF and I need to be able to react to windows being created and destroyed. In winforms, one way of doing this is to override the WndProc procedure to be able to receive and process Windows messages and I am trying to do the same in WPF.

After searching around and fiddling with the code for a week, I just can't get the thing to work.

I only get some messages when the app first starts up and I may get some messages only when opening a new explorer window although the message itself is never the "window created" message. Apart from that, the WndProc function is never called no matter how many windows I open, switch to or close.

I tried following the answers from Getting Wndproc events to work with WPF?, from How to handle WndProc messages in WPF? , several other websites from search results as well as the "MVVM-Compliant way" described in this blog post which is also referenced in one of the answers on stackoverflow.

By all accounts, this should work but it just doesn't. I tried it on two different computers, both running Windows 10 and the behavior is the same. WndPorc is just not called.

Here is some of the code I tried to use as well as a link to the zipped VS project:

Update

Microsoft acknowledged the issue:

Gepost door Microsoft op 13/10/2017 om 11:38

Thank you for reporting this. We are aware of this issue and are fixing it in a future version of .NET. There is also a related issue that is being released in a servicing fix that will drastically reduce the possibility of hitting this problem. This will be serviced relatively soon.

Problem

Our WPF application is being used on tablets using touch (no stylus) and we are experiencing issues after the installation of .NET Framework 4.7. Two scenarios can occur after using the application for a while: either the application freezes completely and has to be restarted or all touch functionality in Popup or Window elements is disabled. There is quite a difference between the two but I believe the cause is the same.

Scenario 1: full freeze

• The application becomes fully unresponsive, the application must be closed using the Task Manager
• Touch nor mouse can be used
• Sometimes the following error is thrown before the application hangs:

Index was outside the bounds of the array.

This is the stacktrace:

There are dozens of simular Questions to this topic on StackOverflow already and I browsed a lot without finding a suitable answer, that would apply to my problem.

I have a WPF Window in a MVVM pattern, which has quite a lot of buttons that open other windows. I'd like to have most of my windows appear in relation to my buttons (I have a toolbar in the top right corner of my MainWindow and want most of the smaller windows to appear right below my buttons), or at least on the same screen as my MainWindow.

At first, I thought this wasn't such a big deal and there were plenty of blogs and questions on google to this topic, yet all of them won't work on my project.

I am using the MVVM pattern, which means:

• I can't use Mouse.GetPosition(ButtonName) on my Buttons, as the ViewModel doesn't know their names
• I can't use Mouse.GetPosition(sender) in a Click-Event, as most Buttons use commands.
• I also apparently can't use PointToScreen in my view's code behind, as it will cause an exception (this visual object is not connected to a \"PresentationSource\")
• I could use Mouse.GetPosition(this) on a MouseMove-Event in my view's code behind and hand it down to my ViewModel, which will update a Property, that I can use in my Commands when creating the window, but I don't like the idea of having to update a property permanently. Also without PointToScreen I can't set the point in relation to my screen.
• I can't use any WinForms references, as this would cause conflicts in my current project

• Additional to Buttons, I also host a UserControl with Hyperlinks in my MainWindow, which open additional windows, that should be in relation to the hyperlinks.

• there are quite a few different answers to a question here, but none of them did work for me.

• As my ViewModel doesn't know the XAML elements I can't simply access by point notation as suggested here

• My ViewModel doesn't know a WorkingArea, so I couldn't even get my window to appear on the same screen as my MainWindow as demonstrated here
• As most of the other answers, this one seems like it won't work in a ViewModel

I've spent quite some time on a problem, that rather seemed trivial at first, already. Since most questions I've viewed so far seem to target windows without MVVM, what would be the proper approach in a ViewModel to set the location of a window to either my mouse coordinates or the coordinates of a clicked button?

edit: MouseDownEvent as requested in Comments: Xaml:

I am calling HwndSource.AddHook() to get the messages to be handled in my WPF window. I wonder whether I need to call HwndSource.RemoveHook() when the window is destroyed - this window is not the MainWindow. If so, what is the right place for calling it (Closing())?. It seems the Hooks are removed when the window is destroyed.

I'm trying to trace WPF operations by ETW provider embedded into PresentationSource. When I traced real application I was bit by changing already triggered operation Id from Post to Start phase.

At the source code I found that Id is relied on address of the object which might be changed during GC operation: https://referencesource.microsoft.com/#windowsbase/Base/System/Windows/Threading/DispatcherOperation.cs,dff34e59b0cffd1e

Does anybody know how to track by ETW such object relocation?

I want to know if I have completed an input word on a wpf textbox, but TextChanged event will fire even if I am typing in IME input. Therefore, I try to distinguish WM_IME_CHAR from WM_CHAR message (like I did in c++ windows form). I can get window message for a WPF window using this method, but how can I get the message specifically for a textbox inside WPF window?

Here is my XAML: