Trying to use a FileOpenPicker while running the app as Administrator will crash the app

[bogdan-patraucean]

Describe the bug

I am trying to open a File Picker but it works only if I am not using the app in elevation mode.

I'm getting the following error:

System.Runtime.InteropServices.COMException: 'Error HRESULT E_FAIL has been returned from a call to a COM component.'

The error appears when the code tries to execute the following line of code:

var file = await picker.PickSingleFileAsync();

Steps to reproduce the bug

1. Create a WASDK app using version 1.4.2 and .NET 7
2. Create an extension method so you can get the Window Handle

AppWindowExtension.cs

public static IntPtr GetHandle(this Microsoft.UI.Xaml.Window window)
{
    return WinRT.Interop.WindowNative.GetWindowHandle(window);
}

3. Make the MainWindow available outside the App class

App.xaml.cs

public static Window MainWindow { get; private set; }

4. Use the generated Button_Click event method to open the File Picker

MainWindow.xaml.cs

var picker = new FileOpenPicker();
picker.FileTypeFilter.Add("*");

InitializeWithWindow.Initialize(picker, App.MainWindow.GetHandle());

var file = await picker.PickSingleFileAsync();

5. Build the app and try to Run as Administrator (it's not neccesary to configure elevation, just right click on the app works)
6. Click the button to open the File Picker
7. The app will crash :(

Expected behavior

I would expect this basic feature of picking a file to work even if I run the app as admin.
My app has a lot of features that require elevation so getting rid of elevation is not an option for me.

Screenshots

No response

NuGet package version

1.4.2

Packaging type

Packaged (MSIX)

Windows version

Insider Build (xxxxx) (only on Windows 11)

IDE

Visual Studio 2022

Additional context

The same for FolderPicker

[Petrarca181]

I can confirm this bug. Any temporary workground for this?

[bogdan-patraucean]

@Petrarca181 yes, you can use directly PInvoke with CsWin32, but it's too much overhead if you ask me.

[qianchen36]

我在WindowsAppSDK 1.1 Preview 3中使用FolderPicker时遇到了同样的问题，但是我的程序需要提升的权限
I had the same problem using FolderPicker under WindowsAppSDK 1.1 Preview 3, but my program required elevated privileges

[lukedukeus]

@Petrarca181 I had to write my own with P/Invoke as well, It's basic and blocking / non-async, but gets the job done. Mostly copied from here.

using System;
using System.Runtime.InteropServices;

namespace Namespace
{

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public struct OpenFileName
    {
        public int lStructSize;
        public IntPtr hwndOwner;
        public IntPtr hInstance;
        public string lpstrFilter;
        public string lpstrCustomFilter;
        public int nMaxCustFilter;
        public int nFilterIndex;
        public string lpstrFile;
        public int nMaxFile;
        public string lpstrFileTitle;
        public int nMaxFileTitle;
        public string lpstrInitialDir;
        public string lpstrTitle;
        public int Flags;
        public short nFileOffset;
        public short nFileExtension;
        public string lpstrDefExt;
        public IntPtr lCustData;
        public IntPtr lpfnHook;
        public string lpTemplateName;
        public IntPtr pvReserved;
        public int dwReserved;
        public int flagsEx;
    }
    public static class FilePicker
    {

        [DllImport("comdlg32.dll", SetLastError = true, CharSet = CharSet.Auto)]
        private static extern bool GetOpenFileName(ref OpenFileName ofn);

        // usage: string filename = FilePicker.ShowDialog("C:\\", new string[] { "png", "jpeg", "jpg" }, "Image Files", "Select an Image File...");
        public static string ShowDialog(string startingDirectory, string[] filters, string filterName, string dialogTitle)
        {
            var ofn = new OpenFileName();
            ofn.lStructSize = Marshal.SizeOf(ofn);

            ofn.lpstrFilter = filterName;
            foreach (string filter in filters)
            {
                ofn.lpstrFilter += $"\0*.{filter}";
            }
            ofn.lpstrFile = new string(new char[256]);
            ofn.nMaxFile = ofn.lpstrFile.Length;
            ofn.lpstrFileTitle = new string(new char[64]);
            ofn.nMaxFileTitle = ofn.lpstrFileTitle.Length;
            ofn.lpstrTitle = dialogTitle;
            if (GetOpenFileName(ref ofn))
                return ofn.lpstrFile;
            return string.Empty;
        }
    }
}

Then, you can call it like so:

string filename = FilePicker.ShowDialog("C:\\", new string[] { "png", "jpeg", "jpg" }, "Image Files", "Select an Image File...");

Or, if you must use naitive, you can work around this bug by running the rest of your code as admin, and this not as admin using impersonation.

[AdamBraden]

@manodasanW - crashes right at the PickSingleFileAsync() call.

[derekhe]

Yes, the problem still exist in WinUI3 with admin right. Please fix this!

[AdamBraden]

After discussing this with the filesystem team, the recommendation is to use the IFileOpenDialog apis from CSWin32. Here is a recent thread discussing this very topic - FileOpenDialog in CsWin32.

[bogdan-patraucean]

@AdamBraden thank you for oferring this workaround. Any updates related to fixing the issue?

[AdamBraden]

What we could consider is creating a WinAppSDK wrapper around IFileDialog apis that provide an equivalent to the Picker apis. There are some opportunities to improve as well - StorageFiles are very heavyweight objects, and so we could consider returning something more optimized.

[bogdan-patraucean]

@manodasanW, @MikeHillberg, @AdamBraden, hi! Any progress on this? I would appreciate an update. I'm curious how it goes.

[fredemmott]

https://github.com/OpenKneeboard/OpenKneeboard/blob/e45bbfd46d953a562a9aaa59f38607472d9ea830/src/app/app-winui3/FilePicker.h and https://github.com/OpenKneeboard/OpenKneeboard/blob/e45bbfd46d953a562a9aaa59f38607472d9ea830/src/app/app-winui3/FilePicker.cpp are an example of using the IFileDialog workaround with modern C++ and cppwinrt

[derekhe]

WinUI3 makes me crazy for even basic stuff is not working. I return back to use electron.

[bogdan-patraucean]

Indeed, such a simple thing like a FilePicker requires advanced knowledge and years of experience to understand. I'm a C# developer and I need to use unmanaged code with C++ to open a file picker...this is not how developement experience for WASDK should be.

[bogdan-patraucean]

I just discovered that on Windows 10 it works. The problem is only on Windows 11.

[fredemmott]

Same problem on windows 10 here.

[bogdan-patraucean]

Same problem on windows 10 here.

what version do you have?

[PavlikBender]

Any news? I have same problem

[PavlikBender]

Thanks to @castorix . I found workaround for me and made interpretation of it https://github.com/PavlikBender/Pickers

[Balkoth]

It's 2024 and Windows App SDK has no working file dialog. What an achievement.

[tbrummel]

Ah, seeing that new post reminded me that I never did follow up here.

I rewrote my music server app in WPF and it runs perfectly on Win 10 & 11 and I can deploy it (copy the files to another PC) with ease! I can also run it 24 hours a day -- and use memory! It's amazing! I think this WPF thing could catch on!

Or maybe I'm one of the few remaining developers who still write code they want to run on PCs and have no desire for a "UI framework" that throttles their memory usage and app performance. If I were targeting a mobile device or needed to worry about batteries, I would welcome such features -- and I'd probably have little need for an open file dialog.

This could be a simple case of misinformation - I was under the impression that WinUI3 was for writing desktop apps. Honestly, I wish it were, but I don't think a framework that arrests so much control from the developer is going to succeed for serious desktop apps.

[uixiu]

It's 2024 and Windows App SDK has no working file dialog. What an achievement.

Also, the browse folder picker can't pick the same folder next. To enable the selection button, one should trick the dialog buggy logic by going elsewhere and returning 😁. I went back to Winforms (win32) dialogs in WinUI 3.0 ✌🏻

[hclazarin]

This was reported over 2 years ago, I can't believe there is still no acceptable solution or at least a reliable workaround. After 6 weeks working on a new major project facing issue after issue after issue with this SDK this is the last one, I give up. This framework is certainly a massive load of crap and will spank the architect who decided for it lol. I rather rollback to WPF and lose a few weeks than getting frustrated with nonsense every 3 days for the next few months.

[smourier]

This was reported over 2 years ago, I can't believe there is still no acceptable solution or at least a reliable workaround.

FWIW, you can use Winforms's OpenFileDialog (or WPF) easily from WinUI3 https://stackoverflow.com/a/78842081/403671

[mominshaikhdevs]

What we could consider is creating a WinAppSDK wrapper around IFileDialog apis that provide an equivalent to the Picker apis. There are some opportunities to improve as well - StorageFiles are very heavyweight objects, and so we could consider returning something more optimized.

YES. This is The Right Solution that should have been provided by Windows App SDK already.

#8 (comment)

---

@AdamBraden @manodasanW @MikeHillberg
It's really 2024. whats the latest update on this?

[Apollo199999999]

It's been 2 years and there's still no proper solution to this? Using WinForms OpenFileDialog as a workaround shouldn't be an acceptable solution.

[AlexanderBlackman]

This implementation works for me, but it's not on NuGet so you have to include it manually.
https://github.com/PavlikBender/Pickers

It's been 2 years and there's still no proper solution to this? Using WinForms OpenFileDialog as a workaround shouldn't be an acceptable solution.

I feel your pain, I checked this thread again today when the WinUI 3 Gallery proudly announced it added a FilePicker sample, but no, it is still as broken as usual.

[MartyIX]

Hit this today in .NET MAUI with unpackaged mode. Frustrating bug. :|

[sungaila]

The picker situation is aweful right now. For a packaged Desktop app there are two options:

• Win32 pickers: do not work in AppContainer/PartialTrust (no RuntimeBroker) and might not work in AOT (COM is not available in .NET compiled ahead of time)
• WinRT pickers: do not work when elevated/with admin rights (COMException with no context) and do not work in AppContainer/PartialTrust (WinUI 3 has no CoreWindow)

So the only option might be to build a custom picker that uses WinRT APIs, I guess? What a mess.

[Cacsjep]

when you think for an whole hour you are crazy and you doing something wrong and founding then such a huge github issue about a file dialog, what the hell

[tbrummel]

Over 2 years and still no fix? This means that the project is ranked low in the dev team meetings and just never makes the cut for release. This means that the framework is targeting mobile apps (that could maybe also run on a desktop). I wish Microsoft would just make that clear. There are a lot of decisions to make in choosing platforms and APIs for a project and letting people know that WinUI is not being developed as a desktop focused solution (but it might work for some scenarios) would be nice. It's sad that developers are wasting time with debugging and investigation of issues that have been known for years -- and for what are clearly basic operations. I mean if you're trying to inject a custom shader into the UI pipeline, you might expect to run into some issues -- but not when trying to open a file!

I haven't revisited WinUI since my original post here and it has been on my "todo" list -- but I guess I can just remove it as there is, apparently, little progress in the direction I need for desktop/business apps/utilities. This truly saddens me. If/when I need to write a mobile photo viewer, I might check it out again...

[MartyIX]

Is #4945 a fix for this issue?

[Rybasum]

@MartyIX Interesting... Do you know if this works in AppContainer? The test app included there has runFullTrust capability.

[MartyIX]

No idea. Unfortunately. No response from the PR author.

[mominshaikhdevs]

#4710 (reply in thread)

[Rybasum]

@MartyIX #4710 (reply in thread)
It looks like "the preview version of these APIs will not initially support app container scenarios". Thanks, Momin Shaikh!

[alski]

Just adding myself to the list wanting this