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That’s the plan. Long paths will work if (1) the OS supports it and (2) the app is targeting.NET Framework 4.6.2. However, it’s important to keep in mind that Windows is large not every API and component will support long paths but we consider those bugs at this point. Same is true with.NET itself. We haven’t yet updated the VM to support loading DLLs on long paths. So take this feature in.NET Framework 4.6.2 as a large step in the right direction, but don’t expect that Long Path issues are completely gone yet. Can I ask for clarification on long path support please?
In the above post is says: “Allow paths that are greater than 260 character (MAXPATH). Paths that are longer than MAXPATH are allowed by the BCL. The BCL APIs rely on the underlying Win32 file APIs for limitation checks.” If the Win32 APIs have not been updated to remove the MAXPATH check then surely long path support is not going to work even if the BCL has changed?
In addition, you say long paths are only supported if the underlying OS supports long paths? As far as I know the only operating systems that supports long paths today is Windows 10 anniversary edition.
Does this mean that applications running on Windows Server 2012 R2 will not support long paths even if they are targeting.NET framework 4.6.2? A compatibility matrix showing OS and.NET version would be very useful. The only OS that supports long paths without you doing any extra work (other than enabling the feature) is Windows 10 Anniversary Edition. You can, however, use long paths on any OS if you use the?
Syntax which is now supported by this feature. You can look at my blog posts for tons of details on what works and how it works. With the feature turned on.NET doesn’t preemptively check path length as it used to (in Path.GetFullPath). If you call any other API that actually hits the disk, the OS will return an error if you’re not using?
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Or if it doesn’t have the feature (or it’s disabled) and.NET will surface this as PathTooLong.NET Core does the? Work for you.
We want to do the same thing in 4.x, but we currently don’t have a timeframe for it. One final note- IsolatedStorage already worked with long paths on 4.x (on all OSes). Thanks for the clarification.
Given that Windows 10 is a client OS and the problems (for us at least) surface in server editions predominately are you aware of any plans to back port this feature into Windows Server 2012 R2? I appreciate this is a “Windows” thing rather than a.NET thing however for the customers that’s really irrelevant – we just want it to work in our applications and platforms. Any links you can share on the plans to resolve this in the Windows Server world – 2012 or 2016 would be useful. Thanks for looking at this problem, after many years of it being ignored it’s great to see it finally being dealt with.
I have nothing specific I can share on Server, but I would expect that the changes will come in Server as well. It is the same codebase after all. I really can’t speak for the Windows team, but I doubt they’ll back port their changes- perhaps with strong feedback that shows how specific scenarios can be met with this initial support.
Personally I’d rather see them put cycles towards getting the rest of the story fixed first if given a choice (CMD, shell, etc.). There is so much more that needs done before we can effectively be “done” with MAXPATH in the same way we are “done” with 8.3 file names- and that level of back porting would be a huge amount of risky work.
Practically it doesn’t seem possible although I’m totally with you on the desire for it- I’ve wanted this gone for many, many years. ? If it helps any I can tell you additional work.is. being done. There have long been advocates for this space around MS and we will continue to push on the problem.
Keep your feedback coming- the more user feedback we get the easier it is to prioritize this work against other features. Regardless of “compatibility switches”,.NET Framework 4.6.1 caused issues for applications such as Exchange. At that time we were advised to remove 4.6.1 and as Michel indicated we here in the real world could use the ‘BlockNetFramework462’ registry key to block its installation on our application servers. You response to Michel seems to imply that a new version of.NET such as 4.6.2 cannot cause an issue with an application and if it does, its due to a problem lies with the application. Is that what you are saying?
Regardless, is there or will there be a switch that will block installation of 4.6.2 if there is any doubt about its compatibility with a particular application? It is a little awkward when you want to pull in behavior a newer TFM (Target Framework Moniker). The convention is that flags are to opt into legacy/compatible behavior when true and they’ll default to true if you don’t target the TFM where the feature was introduced. You always get the “latest & greatest” behavior when targeting the latest unless you explicitly opt out. For this particular feature opting without moving your TFM forward is more common than usual I think. Apps will likely work just fine if the feature isn’t there- so deciding not to require 4.6.2 but light up if present (e.g. The switches) is probably a choice many will make.
Note that there are actually.two. switches involved for full support- one for the normalization changes and one for the MaxPath check.
I go into more detail in my blog: “Switch.System.IO.UseLegacyPathHandling=false;Switch.System.IO.BlockLongPaths=false”. All paths to files should work (e.g. Anything that works directly with CreateFile should work). This with the caveat that you have to be in full trust if you want to use?
As opposed to. For pipes you need to go through System.IO.Pipes as FileStream has a specific check for handle type.aspx There is currently no alternative for mailslots unfortunately as the logic for determining sync/async in FileStream doesn’t work with mailslot handles (so you can’t even pass a handle you open yourself). I’m entertaining allowing all file handle types in FileStream to allow for corner cases such as mailslots. (Specifically because I want to allow not using CreateFile directly without depending on custom.NET classes for things like mailslots.) You can add your comments to my CoreFx PR at if you wish. Sorry, my original reply is awaiting approval: All paths to files should work (e.g. Anything that works directly with CreateFile should work). This with the caveat that you have to be in full trust if you want to use?
As opposed to. For pipes you need to go through System.IO.Pipes as FileStream has a specific check for handle type.aspx There is currently no alternative for mailslots unfortunately as the logic for determining sync/async in FileStream doesn’t work with mailslot handles (so you can’t even pass a handle you open yourself). WPF.NET 4.6.2 Windows 10 Soft Keyboard support not working? Hi, I’m using WPF on.NET 4.6.2 on Windows 10 Pro 1511 (10586.494) and I don’t see any improvements with touch keyboard when TextBox get focus. Keyboard still doesn’t automatically show on got focus and disappear on lost like with UWP apps. I reinstall.NET 4.6.2 and developer target pack on my machine but nothing changes. I have targetted new WPF application on 4.6.2 using Visual Studio 2015 Update 3.
Anyone has “Soft Keyboard Support” working on WPF app on Windows 10 (every version or I have to upgrade to Anniversary?)? Have I do something to get this feature working? “Soft Keyboard Support” works only on Windows 10?
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What about Windows 8.x and 7? This.NET framework update breaks numerous running WPF applications due to the removal of the MemoryPressure framework class, often used to work around a serious WPF design flaw (which, gratefully, was itself fixed in 4.6.2).
If the developer didn’t check for null when referencing the class (and why would they, for a static object that is part of the framework?) their app crashes. Which means, of course, that upgrading to Windows Anniversary Edition with 4.6.2 immediately kills our applications. Anyone want to explain why my prior comment on this from yesterday morning has not shown up yet?
This is a serious, serious issue, and not the first time the in-place upgrades to.NET have caused us grief. I don’t know if this is the cause, but after upgrading to 4.6.2 just a couple days ago, Outlook 2016, TFS Power Tools, and Windows Explorer are now all crashing. Outlook 2016 can’t be opened at all, and the other 2 have random crashes. To my opinio, here in the release notes is a very wrong Statement on the “consumer” Situation with the length of file paths: “This limitation doesn’t usually affect consumer applications (for example, loading files out of “My Documents”),”. This is easy to say, but users even do not notice when they exceed this lenght, they even do not know about this Limitation at all (because it is ridiculous and something of the DOS – 1980ies), and they definitely do exceed the path lenght – and loose data. This Limitation also exists on Windows Servers, and in my Company much data was lost because of exceeding the Limitation by users.
Even IT departments sometimes are not aware. Why was this very fundamental and serious Limitation not addressed with e.g. Windows 2000 or earlier? Thanks to Jeremy Kuhne for saying that the summer update of Windows 10 now resolves this.
It would have been better to say that it hits developer scenarios much more frequently than consumer at this point in time. We are aware, however, that the typical end user will hit this more often as they continue to accumulate files (notably pictures). We absolutely want to see the issue resolved for everyone in the entire ecosystem- there is a lot more work still to be done to make this happen. There were a variety of mitigations that have been done over the years for long paths, but they do only go so far. As 10-15 years ago the need was not as pressing it was harder to argue for the investment needed beyond mitigations.
Another part of the reason that things weren’t handled earlier was due to higher complexity of solving it when we had much older OS versions (and lower end hardware) in the support matrix. A lot of things changed over the past few years to help push this issue over the edge.
I discussed some of what went into that in a recent.NET Rocks! Podcast if you’re interested in hearing more on the topic. WPF & scrolling focused input control not to be covered by soft keyboard – any (official/ unofficial) samples?
From.NET 4.6.2 Preview announcing post comment: Mario Vernari A bunch of good news! Just a question about the Soft Keyboard support for WPF. The problem wasn’t just the opening/closing of the keyboard, but sometimes the textbox was covered by the overlapping keyboard. Does the new feature shift the viewport according to the actual useful area? 4 months ago Reply Stacey Haffner MSFT Thanks for review and feedback. The Soft Keyboard feature will not add the functionality of shifting viewport at the framework level.
We think apps are best place to handle this, more guidance/samples on how to achieve the desired scenario(s) at an individual app level will be shared in coming months. There are some oficial samples for scrolling view to not be covered by soft keyboard for Windows Store/UWP apps with InputPane class f.e or (and standard TextBox in UWP has this feature), but I haven’t found any with WPF. Is it good enough solution? But it requires synchronize to moment when keyboard open.
Thank you very much, it is what I need. Reading readme file I was noticed: “In.NET 4.6.2 or above on Windows 10 Anniversary Update or above, WPF supports automatic display of the Windows touch keyboard (tiptsf).” Word “or” between 4.6.2 and Windows 10 Anniversary Update suggests that the new feature also could work without Windows 10 Anniversary Update or even Windows 10 (Windows 8.x?, Windows 7 has quite different touch processing which seems working for everytime).
From my practical experience I could say that touch keyboard in WPF started working after I updated my Windows 10 to Anniversary Update. BTW reading.NET 4.6.2 changes document it seems the new feature works on all versions of Windows 10. The key changes present in Windows 10 Anniversary Edition are not present in any other Windows version. If you look at the code that instantiates the InputPane, IInputPaneInterop is a new public COM interface that we use in order to feed IInputPane an HWND, where before it only worked with ICoreWindow. This opens the InputPane to all Win32 applications (not just WPF). There are other changes as well internal to the Touch Keyboard focus tracking algorithm that are necessary to support WPF again due to the way the native portion of the WPF touch stack handles WMPOINTER messages. As such, the requirement is Windows 10 Anniversary Edition.
Note that the focus tracking changes were initially debuted in Windows 8, which is when WPF touch keyboard support stopped working. The Windows 7 stack is wholly different, as you say, and has historically worked fine. This documentation on the NullReference is rather vague “In this release, we extended the CLR debugging APIs to enable the debugger to request more information and perform additional analysis when a NullReferenceException occurs. Using this information, a debugger will be able to determine which reference is null and provide this information to you, making your job easier.” But yet provides no example/description or screenshot. I’ve tried it and don’t see any additional information in terms of letting me know which reference is null Has anyone else tried it?.NET 4.6.2 on Windows Server 2008 R2 breaks SignedXml.CheckSignature.
On newer versions it seems fine. Code that throws this exception is trivial (copied from MSDN sample), and it works after I uninstalled.NET 4.6.2 and re-installed 4.6.1: Type: System.Security.Cryptography.CryptographicException Message: Object was not found.