This may not be possible, but I am looking for a way to prevent the user from switching away from my application until it is closed.
I am using AppActivate and SendKeys to send data to the last window opened before my application was started (I'm using GetTopWindow, GetNextWindow, IsWindowVisible, and GetWindowThreadProcessId to get the PID of the last active window). However this seems to be unreliable based on when I get the PID of the last window in my application and whether the user starts switching to different windows while my application is running which can cause the wrong window to pop up.
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TL;DR Can I make a VB.net form visible on the Windows lock screen [i.e. when a user hits WIN+L]?
I wrote an alert system that notifies staff of a 'lockdown' in vb.net. This has been tested in drills a few times but today it was noted that the 'alert window' does not appear when the screen is locked.
The alert window does make an alarm sound, which can still be heard even when the computer is locked but this is dependant on the machine having speakers that are turned on...
The workstations are running Windows 7.
Edit
I am not looking to spawn a separate process, just get the 'lockdown.vb' form showing on top of the windows lock screen.
Googling this has just given me a load of tutorials on making a lockscreen...which is not what I'm after, hence the question. :-)
I have written a WinForms driver safety application for a windows tablet device that will blank the screen (display a full screen blank topmost window) when it detects that the car is moving at say more that 15km/h (using the tablets GPS).
The software has worked fine under Windows 7 but I'm struggling a bit to get it working under Windows 8. My first challenge is to display the blank screen when the Metro start menu is currently displayed. So if the user has the Metro start menu displayed and the car starts moving > 15 km/h my blank screen should display... I need to steal the focus from the metro interface and display my blank window on the desktop.
To test this I wrote a simple vb.net app in 2010. It had a form with a timer firing every 3 seconds. In the Tick event I had the code:
Beep()
Me.Activate()
When I ran this with the debugger and pressed the windows key to show the Metro Start Menu, it worked... The focus switched back to the desktop (and my window). However, when I ran this without the debugger and did the same thing I could hear the beeps but the focus never switched back to the desktop.
Any ideas why the behaviour would be different? Any ideas on how I replicate the same behaviour I get when the debugger is attached?
I have tried a few things like AppActivate, setting the form TopMost, BringToFront but unfortunately this hasn't worked.
The only half solution I have come up with is to send a windows button keystroke but this has other issues.
Windows specifically tries to prevent applications from stealing the foreground from other apps. See the SetForegroundWindow documentation for commentary on this and the factors that can let an application come to the foreground (all of the methods you are trying essentially come down to a SetForegroundWindow call).
Note that one of the explicit blocking circumstances is "The foreground process is not a Modern Application or the Start Screen."
This works for you when debugging because "The process is being debugged" is one of the cases which explicitly allows foreground privileges.
Because this is a generally user-unfriendly thing to do there isn't a good general purpose way to bypass this behaviour and steal the foreground.
Likewise, normal apps cannot run on top of Modern applications or the start screen.
You may be better off locking the system by calling the LockWorkStation function.
I have a program that out of my control will bring up a message box (I didn't write or have source code)
I am trying to find out if it is possible to write a program (visual studio) that can at a set time, say every 10 minutes close all open applications(msgbox) but keep the process going? The application/task name is different to the process name.
It runs on XP and 7.
I've tried google but haven't managed to find what I'm after, all i can find is process kill. Not 100% sure on correct terminology.
You might be better-off writing a program that finds a current open dialog (window, messagebox, etc) and closing it. Sending an Esc keystroke is a pretty easy approach. Here is another SO article that talks about doing this: How to send a mouse click event to a hidden window?
I have a chat application written in VB.net which is used to chat between users who are connected in LAN inside a office . The application popups whenever user gets new chat message. It works fine in windows XP. But sometimes in windows 8 the application fails to popup the chat window. So my chat window is not appearing at the top when popup occurs for new messages.
I have tried using setwindowspos, form.Show(), form.BringToFront() which can bring the form to topmost. But sometimes this will not work properly.
So is there any other method other than those three(which i have mentioned above) i have used which can make the form popup and bring it to front.
Your WinForms app is a desktop application, so it's likely that the reason the pop-up is not being displayed in Windows 8 is because the desktop is not visible.
Remember that Windows 8 brings with it a whole new Start Screen interface and relegates the desktop to an alternate mode. All desktop applications still run, but they run in this separate mode and cannot interact with the new Metro applications (or whatever they're calling them nowadays). Yes, it's too bad that the usability folks at Microsoft didn't listen to Larry Tesler and have decided instead to mode us in, but c'est la vie.
So anyway, the pop-up is still being displayed, but it's being displayed on the desktop, which is not visible. Bringing it to the top isn't doing any good because it's already at the top of all the other windows on the desktop. If you click on the "Desktop" tile in the Start Screen, you should see your window.
Fixing this problem is going to take some work. Forcing a focus switch to the desktop mode is a horrible idea from a usability perspective, and I'm not sure it's even possible. A better solution would be to look into using Toast notifications instead, which can be done from a desktop application.
I am developing a windows service, in VB.NET, that launches a legacy application that performs some work. The service acts as a wrapper around the legacy app allowing users to automate an otherwise manual operation.
Everything is working great, except occasionally the legacy app displays a messagebox. When it does this the process halts until the message box is closed.
As the service will be running on a server there will be no user to close the message box.
The service launches the legacy application in a System.Diagnostics.Process.
Is there way to detect that a message box has been displayed by a process that I have started using System.Diagnostics.Process? And is there a way to close the messagebox through code?
I also found that EnumChildWindows does not return the MessageBox. But I found a site that showed me how to do it. http://vbcity.com/forums/t/105842.aspx
You want to call GetWindow passing in GW_ENABLEDPOPUP. It worked like a charm. Thanks to Scott Waletzko!
Use FindWindow to find the app, the use EnumChildWindows to enumerate all it's childwindows until you find the messagebox (if the messagebox isn't a direct child of the main window of the app you might have to have recursive calls I think).
You might be able to skip the FindWindow call and instead use the MainWindowHandle property of the Process, but I haven't checked if that works.
A good tool for looking at all this is Spy++ which can help you see some information you can get hold of about a running process.