How to read/write value in sharedpreferences xamarin.forms android?

// read values using key value 

public static string GetString(this Application application, string key)
{
var prefs = application.Context.GetSharedPreferences(application.PackageName, FileCreationMode.Private);
return prefs.GetString(key, string.Empty);
}

//write values
public static void SaveString(this Application application, string key, string value)

{

var prefs = application.Context.GetSharedPreferences(application.PackageName, FileCreationMode.Private);

var prefEditor = prefs.Edit();

prefEditor.PutString(key, value);

prefEditor.Commit();

}

or check this link
`http://forums.xamarin.com/discussion/4758/android-shared-preference

How to create Bitmap image and store to sdcard xamarin.forms android?

Bitmap bitmap = Control.DrawingCache;
            Canvas canvas = new Canvas(bitmap);
            ImageView image = new ImageView(Control.Context);
            Java.IO.File file = Android.OS.Environment.ExternalStorageDirectory;
            //Captured chart image
            image.SetImageBitmap(bitmap);
var path = Android.OS.Environment.ExternalStorageDirectory.AbsolutePath;

path = System.IO.Path.Combine(path, e.Name);      
FileStream fos = new FileStream(path, FileMode.CreateNew);

            bitmap.Compress(Bitmap.CompressFormat.Png, 100, fos);