Xamarin android class name references

Question

I have a Xamarin Android project. I am trying to use a custom Action Provider. I am vaguely following the Android java example here: https://gist.github.com/f2prateek/3982054 but porting it to C#. Therein lies the problem.

I created the class SearchActionProvider with the following code:

namespace Erik.Mobile.Screens
{
    public class SearchActionProvider : ActionProvider
    {
    ...
    }
}

The menu resource I've created:

<?xml version="1.0" encoding="utf-8" ?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:id="@+id/actionSearch"
                android:icon="@drawable/searchIcon"
                android:title="@string/actionSearch"
                android:showAsAction="ifRoom"
                android:actionProviderClass="Erik.Mobile.Screens.SearchActionProvider"
                />
</menu>

My package name is com.company.Erik.

In my Activity, I overridden OnCreateOptionsMenu() to use MenuInflater.Inflate() on the resource. I assume it is working, because the icon for the ActionProvider is showing up in the activity bar. Clicking it does nothing.

In Xamarin studio, when I start, I get the following error, edited for brevity:

[MenuInflater] Cannot instantiate class: Erik.Mobile.Screens.SearchActionProvider
[MenuInflater] java.lang.ClassNotFoundException: Didn't find class "Erik.Mobile.Screens.SearchActionProvider" on path: /data/app/com.company.Erik-1.apk
[MenuInflater]  at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:65)
[MenuInflater]  at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
[MenuInflater]  at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
[MenuInflater]  at android.view.MenuInflater$MenuState.newInstance(MenuInflater.java:469)
[MenuInflater]  at android.view.MenuInflater$MenuState.readItem(MenuInflater.java:374)
[MenuInflater]  at android.view.MenuInflater.parseMenu(MenuInflater.java:160)
[MenuInflater]  at android.view.MenuInflater.inflate(MenuInflater.java:110)
...

So, clearly I have the wrong value in my android:actionProviderClass in my menu resource. But I have tried many alternates, and nothing seems to work. I tried "com.company.Erik.SearchActionProvider” and “com.company.Erik.Erik.Mobile.Screens.SearchActionProvider".

How is one supposed to refer to a class within an XML file in Xamarin?

Answer 1

I received information back from Xamarin. It seems that case is important, but not in the way I expected.

My namespace is Erik.Mobile.Screens, which has capitalized the first letter of each work.

In the android:actionProviderClass, I need to refer to the namespace in all lowercase. So my class name needs to be erik.mobile.screens.SearchActionProvider.