Cannot create files on Android with Xamarin

Question

I have a Xamarin-Studio App for Android and I simply want to download files and save them locally. But when I try to create a file in the files folder I get an

Answer 1

I finally realized that File.create() was not the problem. I had code like this:

string tmpFilePath = FilesDir.AbsolutePath.stringByAppendingPath (f.Path);
Java.IO.File tmpFile = new Java.IO.File( tmpFilePath);
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:

string tmpFile = FilesDir.AbsolutePath.stringByAppendingPath (f.Path);
Java.IO.File tmpParentFolder = new Java.IO.File(tmpFile).getParentFile();
tmpParentFolder.Mkdirs ();

In my defense, an FileExistsAndIsDirectory exception would have been much more helpful than the UnauthorizedAccessException