Xamarin : Android : System.UnauthorizedAccessException: Access to the path is denied

Question

So I\'m trying to create a file and I\'m getting System.UnauthorizedAccessException: Access to the path \"/DownloadJitters\" is denied. I\'m not sure if it\'s a permissions

Answer 1

If you are still getting UnauthorizedAccessException for write or read file in Xamarin Android. I just written article to resolve it http://bsubramanyamraju.blogspot.com/2019/12/resolved-unauthorizedaccessexception.html

Answer 2

First of all add this permissions to you Manifest:

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Since Android 6.0 (API 23) you need also to request the permissions manually, add this code on your MainActivity.cs on your Xamarin.Android project:

if ((ContextCompat.CheckSelfPermission(this, Manifest.Permission.WriteExternalStorage) != (int)Permission.Granted)
            || (ContextCompat.CheckSelfPermission(this, Manifest.Permission.ReadExternalStorage) != (int)Permission.Granted))
        {
            ActivityCompat.RequestPermissions(this, new string[] { Manifest.Permission.ReadExternalStorage, Manifest.Permission.WriteExternalStorage }, REQUEST);
        }

Since Android 10 you may also need to add android:requestLegacyExternalStorage attribute to your Manifest like this:

<application android:requestLegacyExternalStorage="true" />

Answer 3

Xamarin.Forms (Android solution)

MainActivity.cs

• For apps that target Android 5.1(API level 22) or lower, there is nothing more that needs to be done.
• Apps that will run on Android 6.0(API 23 level 23) or higher should ask Run time permission checks.

protected override void OnCreate(Bundle bundle)
{
    if (Build.VERSION.SdkInt >= BuildVersionCodes.M)
    {
        if (!(CheckPermissionGranted(Manifest.Permission.ReadExternalStorage) && !CheckPermissionGranted(Manifest.Permission.WriteExternalStorage)))
        {
            RequestPermission();
        }
    }
    LoadApplication(new App());
}

private void RequestPermission()
{
    ActivityCompat.RequestPermissions(this, new string[] { Manifest.Permission.ReadExternalStorage, Manifest.Permission.WriteExternalStorage }, 0);
}

public bool CheckPermissionGranted(string Permissions)
{
    // Check if the permission is already available.
    if (ActivityCompat.CheckSelfPermission(this, Permissions) != Permission.Granted)
    {
        return false;
    }
    else
    {
        return true;
    }
}

Answer 4

Ok I Fixed it by changing the saving location to System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal)

Don't ask me why that worked when they need the same permissions but it did.

Answer 5

This looks like a copy and paste error - you should learn to refactor common code and expressions into one value and reuse it.

//Checks Directory exists
if (File.Exists(Android.OS.Environment.DirectoryDownloads + "/Jitters/FavouritesListAdded.txt") == false)
{
    Directory.CreateDirectory(Android.OS.Environment.DirectoryDownloads + "Jitters/FavouriteList/");
    File.Create(Android.OS.Environment.DirectoryDownloads + "/Jitters/FavouritesListAdded.txt");
}

Let's assume Android.OS.Environment.DirectoryDownloads has the value /Downloads. Now go through the code line by line (you should really do this with a debugger):

File.Exists(Android.OS.Environment.DirectoryDownloads + "/Jitters/FavouritesListAdded.txt")

The parameter value here will be "/Downloads/Jitters/FavouritesListAdded.txt" - OK

Directory.CreateDirectory(Android.OS.Environment.DirectoryDownloads + "Jitters/FavouriteList/");

There's no leading slash on the literal string here, so the value will be: /DownloadsJitters/FavouriteList - I'm guessing you probably meant it to be /Downloads/Jitters/FavouriteList.

Rather than making sure slashes are added to all 6 path expressions in your code - just create one variable with the path value and reuse it.