I am designing a Windows Form app. I have an MDIParent form that loads in a maximized state, and loads its child forms in a maximized state as well. However, when I open an OpenFileDialog, or any datareader object, the MDIParent shrinks to a smaller size with all its forms and controls.
This solution Opening child form is causing mdiform to change size and shrink does not apply/work in my situation.
Also this solution https://support.microsoft.com/en-nz/help/967173/restoring-a-maximized-or-minimized-mdi-parent-form-causes-its-height-t did not work for me.
Some background: I have seen this behaviour in almost all my WinForm applications but I have never been keen to sort it out. I was able to narrow down to the causes as highlighted above when I started investigate it. Some posts are describing it as a windows bug, but it has existed for as long as the screen resolutions started going above 1024 (VS 2010) for my case. I hoped it is not just a windows bug...
I hoped it is not just a windows bug...
Feature, not a bug, but it is not one that Winforms programmers like very much. Notable is that there have been several questions about mystifying window shrinkage in the past few months. I think it is associated with the release of Win10 Fall Creators edition. It has deep changes to the legacy Win32 api layer and they've caused plenty of upheaval.
In your specific case, the "feature" is enabled by a shell extension. They get injected into your process when you use OpenFileDialog. The one that does this is very, very evil and does something that a shell extension must absolutely never do. It calls SetProcessDPIAware(). Notable is that it might have been written in WPF, it has a very sneaky backdoor to declare itself dpiAware. Just loading the PresentationCore assembly is enough. But not otherwise limited to WPF code, any code can do this and that might have been undetected for a long time.
One way to chase down this evil extension is by using SysInternals' AutoRuns utility. It lets you selectively disable extensions. But there is also a programmer's way, you can debug this in VS.
Use Project > Properties > Debug tab > tick the "Enable native code debugging" checkbox. Named slightly different in old VS versions btw. Then Debug > New Breakpoint > Function Breakpoint. Function name = user32!SetProcessDPIAware, Language = C. You can exercise this in a do-nothing WPF app to ensure that everything is set correctly. For completeness you can also add the breakpoint for SetProcessDPIAwareness, the new flavor.
Press F5 to start debugging and trigger the OpenFileDialog.ShowDialog() call. The breakpoint should now hit, use Debug > Windows > Call Stack to look at the stack trace. You typically will not see anything very recognizable in your case since the evil code lives in a DLL that you don't have a PDB for. But the DLL name and location (visible in Debug > Windows > Modules) ought to be helpful to identify the person you need to file a bug with. Uninstall it if you can live without it.
Last but not least, it is getting pretty important to start creating Winforms apps that are dpiAware so such a bug can never byte. You kick this off by declaring your app to be dpiAware so DPI virtualization is disabled. Plus whatever you need to do in your code to ensure the UI design scales properly.
Related
I'm having a really strange problem that I just can't figure out. Things I compile in Visual Studio 2015 (C# projects in WinForms and WPF) will not launch outside of Visual Studio. This includes a project that is completely new and untouched. As in, create a new WPF Application, build in debug and release. Go to containing folders click on EXEs and...nothing.
When I run them I get 3 processes appearing in Task Manager (named the same as my application) than cannot be killed (through task manager or command prompt) and nothing else occurs. Nothing in event viewer that seems to correspond to the app. I've attached an instance of VS 2015 to the process and I get the following message: WpfApplication.exe has triggered a break point. Pressing Break takes me to a screen that tells me no debug information is available and pressing continue has no visible effects (I can occasionally see slight movement in the cpu % but not a lot else). Any attempt to stop debugging will cause visual studio to hang and when I end its process VS closes but its memory is not freed up according to Task Manager. All of these same things occur when building in VS2013 and attempting to run outside of VS. Everything runs just fine when run in debug mode inside Visual Studio but outside of it...not a chance.
I literally have no idea where to proceed from here. I can find no error messages or clues to point me in a direction to look. Is there something I'm missing/doing wrong? What steps can I take from here to find the source of the problem?
I've considered it may be something wrong with my computer but I want to explore the possibilities before I do something drastic like a clean install. If the prevailing opinion lies that way then I'll seek help elsewhere!
tl;dr: launching the exe of a compiled application results in no running application and no obvious error messages, how can I proceed from here?
I'm going to post an answer to this because I found out what was wrong but it probably isn't useful to have it hanging around so I'll just delete the question at some point soon.
The main lesson to remember is that the main purpose of anti virus software is to frustrate you as much as possible and if something weird is happening try turning it off briefly and see what happens. You'll probably find that things are now working correctly.
EDIT: I should restate this in a more serious fashion.
Anti virus can sometimes affect things in unexpected ways and turning it off temporarily can save you a lot of time. Keep it up to date too, mine was a version or so old and was not functioning correctly. I updated it and the deep scan now functions as expected rather than silently failing.
How can I create a window which is fully apparent to the user but is not visible in screenshots. I know that this is possible since Neo SafeKeys (an onscreen keyboard to defeat keyloggers) does not appear in the screenshots taken by keylogging software I installed.
To give you an idea, the window is fully visible to the user, however when a screenshot is taken, the Neo SafeKeys window does not appear at all (as if it does not even exist).
Neo SafeKeys states that it uses an invisible protection layer above the window to protect against screenshots. I have searched all over the internet to see how can I reproduce this, to no avail. Does anybody know how this can be performed (windows which is visible to user but invisible in screenshots)?
What you can do is you can prevent the PrtScn key from doing anything when pressed. Take a look at this article while shows you how to do this.
What this article is doing is clearing out the clipboard. What you can do instead is capture the screen image and digitally remove your application, then put the revised image on the clipboard, thus giving the "Effect" of making your window transparent.
Also, you might want to look at this SO question which gives an alternative way to make your window just appear "blue", though its not easy to do.
Does anybody know how this can be performed (windows which is visible to user but invisible in screenshots)?
Use DirectX to render directly to the device.
In your C# application you can set up a global hook to monitor keyboard events. Then your application becomes the global handler for print screens. Now if another application managed screen prints natively, can't stop that, but anything running through windows, you can get at.
The WM_KEYBOARD_LL hook is one of the few global hooks that can be used in managed code because it doesn't require a DLL to be injected into every target.
For some code you can visit here:
Adam's Blog
Keep in mind that these are global hooks so you want to make sure nothing else (other applications) are effected. I've used these in the past as we hosted showing a power point in an application we worked on. Basically we didn't want the user to invoke any powerpoint menus or keyboard short cuts so we used a global hook. We always checked to see whether the users was in a certain area (screen) and in our application, otherwise we would effect other applications functionality (including our own!)
Microsoft Information:
Hooks Overview
There's this.....
visual cryptography
live example here
But this could be easily coded against by taking multiple screenshots and laying them overeachother and such...
If you are using Windows, and you can avoid that screenlogging happens, you can implement a nice solution like a virtual desktop to embed your process into it. When a process is running inside a virtual desktop it is possible to bypass an screenlogger tool that runs over win32 Api.
Check out this article so you can sneak a peek how to implement a nice solution to scape from screen and keyboard monitoring.
http://www.codeproject.com/Articles/7392/Lock-Windows-Desktop?fid=62485&select=3139662&fr=101#xx0xx
The main form of my application constantly turns white in the designer when I perform the following steps:
1) Open form in design mode (All controls are visible at this point)
2) View source code for form
3) Switch back to design view
After performing the steps above, there is nothing visible in design mode for the form (not even the form). I only have this issue with one form in my application and, unfortunately it is my main form where there is a lot of logic. The workaround is to always close the form and reopen it in design mode show that all the components are visible again. I have experienced erratic errors with the designer when I am low on available memory but, this form always produces this symptom and is the only one. Any ideas as to what is causing this? I guess I could always create a new form and try moving all the controls and logic over but, I'd prefer to avoid the work if there is a simpler option.
The diagnostic is that the Paint event or OnPaint method of a control is misbehaving. These methods run at design time so you'll get an accurate visual representation of the control, the way for example that you can see the Image property of a PictureBox at design time. When such a paint event gets stuck in a loop then the entire form stops rendering properly. Beyond a simple bug, the typical reason is that the code is getting confuzzled by the non-standard runtime environment in design mode. You use the DesignMode property to ensure that such code won't cause trouble and is disabled in design mode.
Finding the misbehaving code is the challenge, especially when these are not controls you wrote yourself. Short from removing controls one by one to find the troublemaker, you can use the debugger by starting another instance of Visual Studio and use Tools + Attach to Process to attach to the first one.
From personal experience, I can confirm that this is an occasional issue in both Visual Studio 2003 & 2005 whether VB or C# is used. We patched both versions to the latest service pack and even got hotfixes directly from Microsoft, neither of which resolved the issue.
In the case of VB in Visual Studio 2003, the disappearance of the controls also removed the underlying designer code so we kept having to restore the deleted code from our version control system. Very annoying - as we'd often lose code changes and have to start over.
You defiantly should check the next link:
https://weblog.west-wind.com/posts/2019/Feb/14/WPF-Hanging-in-Infinite-Rendering-Loop?fbclid=IwAR23ZnUrz7buVpFLXOX2qQin1WcifQ6h280EO25URO74NTGDkTedx1TDRb4
here's a quote from the page:
Using the StarDefinitionsCanExceedAvailableSpace Override This setting
overrides the new GridRendering behavior and basically lets you run
with a .NET 4.7.x target in your project, but keeps the old behavior
that was used in previous versions.
There is a configuration setting that can be set in app.config for
your application:
<configuration>
<runtime>
<AppContextSwitchOverrides value="Switch.System.Windows.Controls.Grid.StarDefinitionsCanExceedAvailableSpace=true"
/>
</runtime>
</configuration>
I can verify that using that switch lets me run 4.7.1 and not see the lock up in any scaling mode. After I
had my running version in 4.6.2 back, I once again moved up to 4.7.1
in a separate branch to try this out and sure enough the switch made
the application run targeted with 4.7.1. So there's a hacky
workaround.
It's a workaround though. This 'fix' according to Microsoft improves
grid rendering allocations, providing more precise sizing and also
improves performance and reduces memory usage. On paper this is a
great improvement, but... well, side effects 😃
I suspect this issue is not wildly common as there was not very much
info to be found about it. I think Markdown Monster makes this issue
come up because the startup sequence has a lot of window manipulation.
MM uses the MahApps UI framework which uses Window Animation and extra
rendering frames for the main window, and MM itself moves the window
offscreen for initial render and adjusts window sizing based on screen
sizes and DPI settings if the window doesn't fit on the screen or
would otherwise be offscreen. IOW, there's a bit of gyration to get
the initial window onto the screen that is more likely to hit this bug
than a simple WPF form.
So I doubt that every application needs to worry about this, but if
you have a 4.7.x WPF app it might be a good idea to try it out at
various resolutions and scale levels just to see how it fares.
I have what seems to be a common problem. I am running Windows 7 Home Premium on one of the most awesomest computers (when it was bought last year) and certain visual effects just automatically turn themselves off.
My average user experience rating is high, so it doesn't explain why this happens. The only feature that ever gets turned off is the 'Show window contents while dragging' option. And it really annoys me.
There are currently no working solutions to this problem online. Other than to "there must be a conflict with another app installed on your machine."
And yes, I do know what app is causing this conflict. It's my bloody Internet Provider's software - you know... that app that you absolutely MUST have open at all times when you're connected to the net.
So, I had a thought. What if I could subscribe to an event so that my app that runs in the background will detect when this 'show window contents while dragging' option is turned off - and then my app will simply turn it back on again.
When I do this manually, it seems to stay in effect for about an hour or two, then it gets switched off again.
Is it possible to handle these types of events, and re-start certain visual effect features? If so, are there any resources on this?
I have not been able to find anything on this sibject yet.
Yes the WM_SETTINGSCHANGE message is sent to all windows when a system setting is changed. Then you can call SystemParametersInfo with SPI_GETDRAGFULLWINDOWS to determine if the "Show window contents while dragging" is disabled and use SPI_SETDRAGFULLWINDOWS to enable it.
So all that you will need to do is create an application with a form (that can even stay hidden) and override the forms WndProc and handle the WM_SETTINGSCHANGE message and call SystemParametersInfo using p/Invoke. The p/Invoke definition for SystemParamtersInfo is available at pinvoke.net
Altough what may be easier is change security on the HKCU\Control Panel\Desktop\DragFullWindows registry value so that it can't be changed.
Edit-And-Continue is one of my favorite debugging tools which I have previously used on C# based Winforms and ASP.NET projects. However, I'm running a Silverlight 3.0 application on VS 2008 and whenever I try to make a change (after breaking) it says "Changes are not allowed when debugging Silverlight applications". Also there isn't an "Enable Edit and Continue" option in the project settings.
Does anyone (possibly an insider) know when this feature will be supported by Microsoft???
(I NEED IT!)
I doubt it will ever be a feature, to be honest. EAC has always required you to attach directly to your .exe in order to work. In the case of Silverlight, that .exe is the browser, which is not the .exe you are developing.
If you are looking to edit XAML while running, you might consider a dynamic loading situation where you can refresh the control at runtime. In that case, you can edit XAML while debugging, but I'm afraid you're stuck with the managed code.
EDIT:
One possibility that you might consider (but I haven't tried it) is to write your code against unit tests. Then, there is a tool called TestDriven.net that allows you to debug your tests with EAC (as an advanced feature). From there, you might be able to do some EAC, but you will be doing it via unit tests, not actually in the Silverlight environment.