External storage access denied in xamarin android

Hello all

I just started building apps using xamarin.android and I got stuck in between.

I am working with images and uses the compress function of bitmap and when I read/write image on phone memory, it works fine but when I tried to write on ezxternal sd card, it shows access denied exception, although reading from it is working fine.I had also set the permission of ReadExternalStorage and WriteExternalStorage but still getting the exception.

Here is my code

// Path of PhotoUri and path that I retreived
//var PhotoUri = {content://com.android.providers.media.documents/document/image%3A9104}
//var path = /storage/D660-18BD/memorytest/20170930_230230.jpg
using (var bmp = MediaStore.Images.Media.GetBitmap(ContentResolver, PhotoUri))
{
var fullPath = System.IO.Path.GetFullPath(path);
var dirName = System.IO.Path.GetDirectoryName(fullPath);
var filename = System.IO.Path.GetFileNameWithoutExtension(fullPath);
var ext = System.IO.Path.GetExtension(fullPath);
var newname = System.IO.Path.Combine(dirName, filename + "IR" + ext);
var fs = new FileStream(newname, FileMode.OpenOrCreate); // here I got the exception
bmp.Compress(Bitmap.CompressFormat.Jpeg, 90, fs);
fs.Close();
fs.Dispose();
}

Access to the path "/storage/D660-18BD/memorytest/20170930_230230IR.jpg" is denied.

Can anyone help me to get the solution.

2 Replies

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Devendra Kumar8y ago
@Rupesh

As user has picked file from an external memory card having path

storage/D660-18BD/memorytest/20170930_230230.jpg

I want to compress that file using bitmap.Compress and create a new file there
0
Rupesh Kahane8y ago
1. string tmpFilePath = FilesDir.AbsolutePath.stringByAppendingPath (f.Path);
2. Java.IO.File tmpFile = new Java.IO.File( tmpFilePath);
3. tmpFile.Mkdirs ();
Yet, Mkdirs() does not only create all intermediate directories – as I had assumed – but also creates a directory at the file path itself. So the file could not be created because there already was a directory with the same name. The correct way is:
1. string tmpFile = FilesDir.AbsolutePath.stringByAppendingPath (f.Path);
2. Java.IO.File tmpParentFolder = new Java.IO.File(tmpFile).getParentFile();
3. tmpParentFolder.Mkdirs ();
In my defense, an FileExistsAndIsDirectory exception would have been much more helpful than the UnauthorizedAccessException

OR Try
1. var path = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData);
2. File.Create(path + "newFile.png");