I am using a WebBrowser control as a text editor in a Windows Forms application. For some reasons I need to clear the undo-stack of the browser after certain actions. To achieve this, I use
webBrowser1.Document.ExecCommand("ms-clearUndoStack", false, null);
which works well on every OS but Windows Vista. On Vista I get the following ArgumentException:
System.ArgumentException: Value does not fall within the expected range.
at System.Windows.Forms.UnsafeNativeMethods.IHTMLDocument2.ExecCommand(String cmdID, Boolean showUI, Object value)
Is there a way to avoid the exception or maybe another way to clear the undo-stack?
This command is not available on Windows Vista, as it is posted by msdn "Commands A-C (JavaScript)" article
ms-clearUndoStack
Clears the undo history.
Minimum availability is IE11
IE11 minimum operating system requirements is Windows 7 SP1
Related
I am configuring Windows 10 Enterprise (IoT) to run a custom shell, but running into the "Black screen with nothing other than a cursor" phenomena.
My application - a .Net4 Winforms app - is installed and runs fine from the desktop.
I can launch it as a custom shell via a batch file as per the comments here: How to run an application as shell replacement on Windows 10 Enterprise
But setting my app as a custom shell, I just get the black screen.
I note the comments in the above link about applications being signed, but I have tried two mini test applications (also .net winforms), one signed, one not, and both run fine as custom shells. (My application has several dependencies, not all of which are signed, so to sign it would mean going through the ILMerge mill or similar which I would rather avoid if I can.)
I don't expect people to be able to tell me why my app doesn't run (although that would be nice!) but I am looking for ways of diagnosing this. Looking in event logs, etc, is yielding no information whatsoever. My app keeps its own event log, which is not showing any evidence of the app starting.
Thanks in advance
Problem solved:
If a shell application requires elevated permissions, UAC must be turned off. Turning off notifications via the control panel is NOT sufficient, as UAC is still running in the background - it just doesn't notify you! To completely turn off UAC, edit registry entry:
HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\System and set the DWORD value EnableLUA to 0
Evidence of UAC behaviour can be found in the windows event log at:
Applications And Services Logs -> Microsoft -> Windows ->UAC
I am porting a .NET CF 1.0 WinForms application (for older versions of Windows CE) to .NET CF 3.5 (for Windows CE 6). The problem is that, a few seconds after Application.Exit() is called, I get a flash of a "fatal error" message box, which simply says something to the effect of "A fatal error has occurred and the application will terminate.". Since I'm using a Chinese version of Windows CE, the message is in Chinese and I'm not sure what the exact message is in English. Anyway, the error message then automatically disappears and the application fails to terminate and release resources completely, such that the whole operating system becomes unusable (launching any application would result in the perpetual hourglass animation, docking the device in its cradle also does not cause ActiveSync to connect) until I warm boot the device.
This fatal error apparently never occurred in its original form (.NET CF 1.0) on the older device.
And because it's not a .NET exception, it is not caught by the .NET runtime.
What can I do?
Because you can not catch the exception which is happening at Application.Exit(), this sounds like you are facing a bug I've seen before. Please try to comment out all the lines where you set the Font attribute. If the application exists without the error message, you are facing a bug which affects NetCF 3.5 at WinCE 6.0 only. See this link for more information.
Sounds like a Dispose or Finalizer has a problem that's showing up when the GC is cleaning house. Check all app finalizers and all Dispose overrides. If that fails to find it, look at any worker thread shutdowns (things sitting in blocking calls, reading handles that might be invalidated, etc).
I've came across this issue recently and the issue was the forms weren't being disposed. So what I had to do was on every form load I added the form instance to a global list that contained all opened forms and upon the application exit I loop through the list and did a form.dispose on each. That solved my problem instantly.
I am testing my application (Windows 7, WinForms, Infragistics controls, C#, .Net 3.5).
I have two monitors and my application saves and restores forms' position on the first or second monitors. So I physically switched off second monitor and disabled it at Screen Resolution on the windows display settings form. I need to know it is possible for my application to restore windows positions (for those windows that were saved on the second monitor) to the first one.
I switched off second monitor and press Detect to apply hardware changes.
Then Windows switched OFF the first monitor for a few seconds to apply new settings. When the first monitor screen came back, my application became unresponsive. My application was launched in debug mode, so I tried to navigate via stack and threads (Visual Studio 2008), paused application, started and did not find any thing that help me to understand why my application is not responsive. Could somebody help my how to detect the source of issue.
Download the Debugging Tools For Windows then run adplus in hang mode. The with the resulting .dmp file open in windbg and invoke:
!analyze -v -hang
You should provide more information about what you saw in the call stack and threads windows. Which threads were running? Did you see anything that was waiting in a sleep or join? Have you tried naming your threads so that it's clearer as to what's going on when you pause (though not necessary since you can get this info from the call stack anyway... it's a convenience thing).
I have a service / application which receives notifications of Windows session changes.
I have noted a difference in behaviour between Windows XP and Windows 7 and am trying to establish if it is a bug or a documented change of behaviour.
The notifications come in as a: WTSSESSION_NOTIFICATION.
Windows XP reports as expected: WTS_SESSION_LOGON at windows GUI logon and: WTS_SESSION_LOGOFF at Windows GUI logoff.
Under Windows 7 x64 at gui login WTS_SESSION_LOGON is generated but at logoff I get a WTS_CONSOLE_DISCONNECT event instead of the WTS_SESSION_LOGOFF event.
Is this a bug or have the constant values changed between versions? It is not massively critical for the service I have developed but I would still like to know why this behaves differently.
Only services can receive the WTS_SESSION_LOGOFF event under Windows 7. By the time that the service gets the notification the log off procedure is over (so all apps the user was running are already killed).
i have a WPF application that sits on top of all other windows. 99% of the time it works perfectly however if i dial into my computer from another location using remote desktop and then close the connection and go back to the original computer, my application is not visible. checking the running processes i can see that it is still running however its not visible at all. I assume it has something to do with the remoting but i was wondering if there is some code i can run say every 20 seconds that sits on its own thread that checks whether it is visible and if not will execute some code whether by pInvoke or .NET to become visible again. Any ideas?
Make sure to upgrade to .NET 3.5sp1. There were some changes with remoting which lead to WPF applications being sent as bitmaps in remote desktop in all situations.
In earlier versions of the framework, there were problems with WPF applications causing very odd behavior when combined with remote desktop.
Another idea - make sure you're using the latest and greatest versions of your graphics drivers from your graphics card vendor. WPF makes heavy use of DirectX, and this could potentially be a driver bug preventing the context from resetting appropriately.