Mono For Android 1.9.1


This is a * *preview** release for the 2.0 series. We are doing previews for 2.0 due to the large number of big changes in it. If you are feeling adventurous, try it out and file bugs if anything goes wrong. If you find something that impedes your work, you can uninstall this release and the shared runtime / platform packages on your Android device, and reinstall Mono for Android 1.2.


Visual Studio Users: Download monoandroid-1.9.1.r2-2.msi and install.

MonoDevelop Users: To be prompted about beta updates, go to Help->Check for Updates and set the Update Level to Beta. You should be prompted with beta updates.

Changes Since Mono for Android 1.9.0

(See 1.9.0 Release Notes for changes since 1.2.0.)

Smarter Linker: Our linker spent the summer at linker community college and came away a bit smarter about what your application really needs in order to run, resulting in a significant release .apk size reduction.


  1.2.0 Size 1.9.1 Size
Default Template Release .apk 4.21 MB 2.89 MB


Update Notifications for Visual Studio: Visual Studio will now check for Mono for Android updates automatically and notify you if a new release is available:

To turn this off, or to subscribe to beta release notifications, go to Tools->Options->Mono for Android:

Bug Fixes

  • Fixed InvalidCastException that would result from subscribing to AndroidEnvironment.UnhandledExceptionRaiser.
  • Fix End-Of-Stream translation in Android.Runtime.InputStreamAdapter and related types.
  • 669 : EditText.ImeOptions should be of type Android.Views.InputMethods.ImeAction.
  • 1052 : Race condition in the VS plugin would cause an exception while deploying.
  • 1148 : EditText.IOnKeyListener.OnKey keyCode parameter should be of Keycode type.


Warning: Samsung shipped a broken kernel with Android 2.1, which is not able to support JIT compilation. If you possess a Galaxy-class device with Android 2.1, you will get unexpected results, this is caused by a kernel bug that breaks cache coherency, rendering any engine doing JIT compilation useless. Check with your manufacturer/carrier for an Android 2.2 update.

Xamarin Workbook

If it's not already installed, install the Xamarin Workbooks app first. The workbook file should download automatically, but if it doesn't, just click to start the workbook download manually.