Error Access to the path “/storage/emulated/0/abc.txt” is denied in Xamarin Android

Question

I am trying to run a Xamarin Android app on Android 8 API Level 26 emulator. Its giving exception when I am trying to write logs to file.

Exception:

System.UnauthorizedAccessException: Access to the path "/storage/emulated/0/abc.txt" is denied

Code:

string filename = "abc.txt";
var documentsPath = Android.OS.Environment.ExternalStorageDirectory.AbsolutePath;
var filePath = Path.Combine(documentsPath, filename);
using (FileStream fs = new FileStream(filePath, FileMode.Append, FileAccess.Write))
        using (StreamWriter sw = new StreamWriter(fs))
        {
            sw.WriteLine(text);
        }

I have given the READ_EXTERNAL_STORAGE and WRITE_EXTERNAL_STORAGE permissions also.

Target Android Version: Android 8.0 API Level 26 Oreo

Exception Details:

{System.UnauthorizedAccessException: Access to the path "/storage/emulated/0/NECMobilePos_log21092018.txt" is denied. at System.IO.FileStream..ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share, System.Int32 bufferSize, System.Boolean anonymous, System.IO.FileOptions options) [0x001aa] in /Users/builder/jenkins/workspace/xamarin-android-d15-6/xamarin-android/external/mono/mcs/class/corlib/System.IO/FileStream.cs:239 at System.IO.FileStream..ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share, System.Int32 bufferSize, System.Boolean isAsync, System.Boolean anonymous) [0x00000] in /Users/builder/jenkins/workspace/xamarin-android-d15-6/xamarin-android/external/mono/mcs/class/corlib/System.IO/FileStream.cs:149 at System.IO.FileStream..ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access) [0x00000] in /Users/builder/jenkins/workspace/xamarin-android-d15-6/xamarin-android/external/mono/mcs/class/corlib/System.IO/FileStream.cs:86 at (wrapper remoting-invoke-with-check) System.IO.FileStream..ctor(string,System.IO.FileMode,System.IO.FileAccess) at NECMobilePOS.Client.DroidLatest.FileLogger_Android.SaveText (System.String filenamePassed, System.String text) [0x000d1] in C:\ABC\XYZ\FileLogger_Android.cs:73 }

Sounds like you haven't explicitly asked the user for permission and here's an example — Nick Peppers

Narendra Sharma Narendra Sharma · Accepted Answer · 2018-09-21T13:34:52

For Versions >= 23, you need to provide the Runtime Permissions. You can go through the document from the link below.

https://devblogs.microsoft.com/xamarin/requesting-runtime-permissions-in-android-marshmallow/

Or for testing now, you can go to app permissions and allow storage permission.

Error Access to the path “/storage/emulated/0/abc.txt” is denied in Xamarin Android

1 Answers