CODEWITHSUNDEEP
c#windows-10
Keith Hill
Keith Hill

Reputation: 73

Access to path denied but the file has no restrictions

I'm new to C# and not an expert at programming in general, but I can't seem to figure out what is causing this problem. I am letting the user pick a XML file and then I want to read it's contents. This is in C# making a universal windows 10 app

This is the error I'm getting:

An exception of type 'System.UnauthorizedAccessException' occurred in mscorlib.ni.dll but was not handled in user code

Additional information: Access to the path 'C:\temp\file.xml' is denied.

public async static void pickFile()
        {
            FileOpenPicker openPicker = new FileOpenPicker();
            openPicker.ViewMode = PickerViewMode.List;
            openPicker.SuggestedStartLocation = PickerLocationId.DocumentsLibrary;
            openPicker.FileTypeFilter.Add(".xml");

            StorageFile file = await openPicker.PickSingleFileAsync();

            if (file != null)
            {
                var t = Task.Run(() => { reset(file.Path); });
            }
       }

then

private static void reset(string path)
        {
            String LocationDatafilename = path;
            XmlReaderSettings settings = new XmlReaderSettings();
            XmlReader reader = XmlReader.Create(LocationDatafilename, settings);
            XmlDocument LocationDataXml = new XmlDocument();
            LocationDataXml.Load(Globals.reader);
        }

When I get to XmlReader.Create that's when I'm getting the error. When I look for the cause, the only thing I find is due to permissions, but that isn't the case. Any help would be appreciated. Thanks.

Upvotes: 3

Views: 2513

Answers (3)

Grochni
Grochni

Reputation: 1851

While Peter Torr's answer is correct and is the way Microsoft wants these things to be done, it is possible to make (at least parts of) the OP's code work as well. The reset method will work, if the path is to one of the directories you have permission for. To get these you can use ApplicationData.Current. This object contains properties like LocalFolder, LocalCacheFolder or (what could be interesting for your use case) SharedFolder.

Upvotes: 0

Phillip Ngan
Phillip Ngan

Reputation: 16106

Run sysinternal's ProcMon app, and at the same time run your application. Find the file in the procmon capture, and in the CreateFile entry, you'll find the creation Disposition. This will give you a clue why the creation failed. Also, select the "User" column to show the user performing the operation.

Upvotes: 0

Peter Torr
Peter Torr

Reputation: 12019

You need to operate on the StorageFile directly, since your app doesn't have permissions to directly read the user's files. You can either use the WinRT XML API or you can keep using the .NET API and use the stream-based Create function instead of the one that takes a file name.

Upvotes: 1

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