How to save text file in Xamarin Studio using C#

You write files in Xamarin pretty much as you would any file in C#.

You can use the namespace

Android.OS.Environment

to give you the system folders e.g. to get the path to the SD card you would use

Android.OS.Environment.ExternalStorageDirectory

Here is an example of saving an image to the SD card.

private string SaveToSd()
        {
            var folder = Android.OS.Environment.ExternalStorageDirectory + Java.IO.File.Separator + "ImageFolder";
            var extFileName = folder +
                              Java.IO.File.Separator +
                              Guid.NewGuid() + ".png";

            try
            {
                if (!Directory.Exists(folder))
                    Directory.CreateDirectory(folder);
                using (var fs = new FileStream(extFileName, FileMode.OpenOrCreate))
                {
                    //TODO perform any validation / compression as required
                    return extFileName;
                }
            }
            catch
            {
                RunOnUiThread(() =>
                {
                    var builder = new AlertDialog.Builder(this);
                    builder.SetMessage("Saving image went wrong");
                    builder.SetTitle("Unable to save image");
                    builder.Show();
                });
                return "";
            }
        }