I have an issue about Windows Mobile thread scheduling: I have an application (C#) that detects incoming calls on the telephone. It is said that the operating system is "fully multitasking and multithreaded".
Still, I can detect an incoming call, but after the call is detected, the system application, showing that there is a call incoming, takes over the focus.My application doesn't get to execute itself until the system window (with the call) is deactivated. (something happens with the call).
Is there anything I can set so that my thread (application) executes even when the system window is focused?
All solutions you can come up with for this are based on one thing: a hack. Windows Mobile is not meant to be customized as you wish - Windows CE is. You cannot override the default Windows Mobile phonecall UI, but you can put your own app above it with the correct API calls. However, it will flicker and it will look like s...t.
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I have Win32 desktop bridge application that uses background task to receive push notifications from WNS. I use UWP background task APIs over C++-WinRT
I'd like to be able to receive push notifications even when OS is in sleep so that it wakes up and the app handles push notification. By default OS does not wake up. It did only after manually changing settings value in System->Battery->See which apps are affecting your battery life->Click my app ->Uncheck Let Windows decide option (by default it is always checked) and check Allow the app to run background taks. Now I'd like to do this is manual work on code for better user experience.
RequestAccessKindAsync API allows to let user to change above setting value by showing popup notification to the user and I could do it without any problem in UWP C# sample app. But same code does not show pop notification from my desktop bridge over C++-WinRT. It simply returns false value for below code
auto result = co_await BackgroundExecutionManager::RequestAccessKindAsync(BackgroundAccessRequestKind::AlwaysAllowed,
L"App needs to use background to catch push notifications while device is in sleep");
Can anyone confirm that RequestAccessKindAsync API works from desktop bridge? If not then how I can make sure OS and the app will always be able to wake up from sleep when it receives push notification?
UPD: Raised request to enable this API from desktop brige here
This is a missing feature. When we designed this API a couple of releases ago we didn't consider desktop bridge apps would be calling it - but clearly there is a use case for supporting this. I have notified the team about this gap, but I'd also encourage you to log a feature request here: https://wpdev.uservoice.com/
Two possible workarounds:
(1) you could add a dummy/empty UWP foreground app to your desktop bridge app. You can then launch this on startup and request the background access from there. This will be a bit ugly, but you could make it look like a splash screen :-)
(2) you can instruct the user to go into the Settings app to set your app to always allowed. You can help them do that with a deep link to the battery save settings, but they will still need to manually flip the switch.
We're writing a cross-platform C# "Xamarin" application; right now we're just targeting the iPad. The application has two features relevant to this question:
The app requires that the user authenticate to the app (in addition to logging onto the iPad)
The app connects to a remote device over Bluetooth
So the question becomes, what happens when the user switches to another app, which results in our app's OnSleep() being called. In OnSleep() we could immediately disconnect Bluetooth and log out the user, but that seems like poor usability, especially if they are just quickly checking some alarm that triggered or an instant message that came in.
For the sake of usability, we're thinking to have a 1-minute timeout; if the user does in fact pop out and quickly pop back into the app, we'd like things to simply continue on without any loss of communication or re-authentication.
If, in OnSleep(), I set up a timer using Xamarin.Forms.Device.StartTimer(), that timer does not fire while the app is "asleep".
What does it take to have a small background task/thread/process execute, even while the app is asleep? Something that simply waits 1 minute, and then shuts down the Bluetooth communication and sets a flag indicating re-authentication is needed?
I've created a service that runs as the Local System user. This service launches and monitors a Silverlight Out-of-browser application using native interop and the CreateProcessAsUser() method (to run it as the currently logged-in user, rather than Local System). I'm able to get a handle on the spawned Process and do things like Kill() it, however, I've become aware that the service is unable to get a handle to the main window of the child application because the child application is running as a different user. I'm running on Windows 7.
My end goal is to respond properly to when the Process stops responding (i.e. Process.Responding == false) so that I can kill the application and restart it. However, Process.Responding requires a handle to the main window of the process (Process.MainWindowHandle, to be exact), however, in this scenario, Process.MainWindowHandle always returns 0.
I'm stumped here. Is there any way for one user to get a window handle to a process running as another user in Win 7?
Thanks in advance for any and all help.
No, that's not possible. Windows Services are completely isolated from user-mode applications for security reasons. If you could get the handle to a window, you could manipulate and otherwise interact with that window, leaving open a huge security vulnerability.
More information is available here:
How can a Windows Service start a process when a Timer event is raised?
How can I run an EXE program from a Windows Service using C#?
windows service (allow service to interact with desktop)
Need suggestion on replacing Windows Service by invisible WinForm Application
Strictly speaking, what you're using the Windows Service for in the first place is bad design. It shouldn't be creating or launching any user-mode processes, or interacting with the user in any way. Remember that services run even when there is no user logged in! Thus, they shouldn't be starting applications.
A better solution is a simple background application, set to launch automatically when the user logs in. This background application could then launch the Silverlight application, monitor its state, and interact with it as necessary, because both would be running under the context of the same local user account. The effect is similar to a service, but without any of the drawbacks of isolation. The easiest way to do this in Visual Studio is to create a WinForms application (or possibly a WPF application, I have less experience in that area) that simply doesn't show any forms/windows.
I have a C# Windows Forms interactive app and a related C# windows service.
On the particular machines where these are deployed, the login and app startup are automatic. The interactive app always starts well before the service. The app has a status indicator to show when it has connected to the service, but these machines are slow and it takes 45-60 seconds for my service to finally get started. During this time, there is nothing happening on the screen.
I should point out that my service starts quickly... it's the dependent (and other) services that are taking some time to start.
I would like to have some sort of indication of the windows startup progress displayed while the application is waiting for the service. I was thinking of showing a progress bar showing something like started_automatic_services/automatic_services. Is there some other more appropriate method?
One possibility would be to use a WMI event query to monitor the services starting up, which would allow you at least to give an idea of progress
Starting services:
Service 1 started
Service 2 started etc.
The MSDN sample Subscribing to and Consuming Management Events should be enough to get you going, as it specifically illustrates querying services for state changes.
Why not use a tray icon? An image that represents a 'broken' or uninitialized connection to your service would be the initial one used, and once the service comes up you can change that to a 'normal' or 'all is well' icon. Some AV software clients do that.
You could also use the same icon with an overlay, maybe a small hourglass on the lower right corner or something like that, and then remove it.
Maybe showing a progress bar every single time the user boots could be rather intrusive and annoying.
I am developing a C# application (.Net 3.5, Win Forms) which is run on a server, and is accessed by Users using remote desktop. The application keeps freezing on seemingly random occasions on the remote machine (i.e. all GUI components turn to white, task manager reports the application to be not responding), but not when run locally (I'm not entirely sure about that, but failed to reproduce the freeze on my machine).
Has anyone experienced such behavior in his apps that are accessed remotely? What debugging strategy would you suggest? Do I need to consider something special when developing Win Forms applications that are accessed by remote desktop?
EDIT: some notes about the application and the freeze: The application does not recover from the freeze. Also, the freeze does not happen (or did not happen yet) during user interaction, but in between log ins to the remote machine. The application monitors a CFD solver, so it's doing things even when no one is using it.
UPDATE:
We did infact implement detailed logging, writing every function call to a file with a timestamp. Unfortunately, the results were not very conclusive. I.e. the last function call logged always returned correctly. Also, there were some background timers still running, even though the application appeared frozne (GUI completely white etc.). After some trouble we managed to have a look at a crashdump in WinDBG. On the system thread we found a call to OnUserPreferenceChanged() and further up to Invoke.WaitOne(). We can't say for sure yet, but it seems to be the issue decribed in these articles. As a quick fix, I installed a dummy handler to the event mentioned. I'll report how this works out.
UPDATE 2:
As it turns out, a Log In to a remote machine fires several OnUserPreferenceChanged() events. So it was indeed the suspected issue. The fix turned out to be not so easy though. I would have expected that an IllegalCrossReferenceException is thrown everytime a background thread tries to modify a control that was created on the system thread. This does not seem to be the case. I named my system thread and before each access to a control I asserted that the current thread name is the system thread's name. In various places this assertion failed (e.g. in a callback from a timer), but no exception was thrown. After using proper delegation at these places, the freezes stopped. The application runs nonstop for some weeks now and my users are happy again ;)
I do not think the freeze has anything to do with remote desktop. Adding logging was a good suggestion. I have a few suggestions, but without knowing the details of you application I can't get too specific.
The simplest suggestion I have is to check the memory useage and CPU usage in task manager when the freeze occurs.
If adding detailed logging is not an option, add just enough logging to know WHEN the application freezes. This could simply be a thread in the application which writes a timestamp to a file once a minute. Then you can see if there is any pattern in when it freezes, such as after a user has logged off, or when some of the data which you are monitoring changes, or at a certain time each day, or after being online for a certain amount of time.
A final and very hacky solution is to write a small watch dog application. This application's only job is to periodically check on the main application to make sure it is still responsive. How you dow this various drastically based on what your application does. If the watchdog sees the the main application has stopped, it can kill the thread for the main application and re-start it from the binaries.
if your using application streaming your server could be slowing the connection or waiting for packets that are dropping this can create this if your physical using windows remote desktop then there is your problem intense applications are not supposed to be run though remote desktop
AFAIK, there is no difference. Additionaly, I never experienced such a problem. I suggest, you try the following:
Extend your application with extended logging, to see what the users are doing when your application freezes
Check the network connection that is used to connect to the remote machine
Check the CPU usage during the freeze
If the freeze is for an extended amount of time, try to do the following:
Reproduce the freeze via remote desktop.
Go to the machine you just reproduced the freeze on and log in directly and see, whether the application is still freezed
If it is windows 10 version 1903 plus version. Then probably its the issue of windows. Please try the following settings:
Have read various blogs and concluded that the GPO has to force to use XDDM rather than WDDM. The issue is observed with windows 10 version 1903. Currently tested the workaround on machine NDT-61. It is working fine. Please practice the same for respective environment and let me know if some issue is faced.
Steps to Follow:
Open Group Policy Editor
Explore Administrative Templates
Explore Windows Components
Explore Remote Desktop Service
Click Remote Session Environment
Under Remote Session Environment Disable Use WDDM graphics display drive for Remote Desktop Connections
Note:
This policy setting lets you enable WDDM graphics display driver for Remote Desktop Connections.
If you enable or do not configure this policy setting, Remote Desktop Connections will use WDDM graphics display driver.
If you disable this policy setting, Remote Desktop Connections will NOT use WDDM graphics display driver. In this case, the Remote Desktop Connections will use XDDM graphics display driver.
For this change to take effect, you must restart Windows
Observation:
The policy settings are only available in windows 10 version 1903 and plus [ideally since when the issue started].