Accessing Android APIs

JavaClassWrapper wraps available Java classes; the built-in AndroidRuntime plugin provides context/activity access and callback adapters. This is Android integration, not a universal Windows API or a guarantee of C# bindings for every Java class.

Choose an approach

• For a small call to an available class, use wrapper reflection if exposed by your language/build.
• For an SDK with lifecycle, permissions and complex types, create an Android plugin: explicit contracts are easier to maintain.
• For C#, first check the installed SDK for the required wrapper. Do not translate another language’s example by changing syntax alone.

Contracts

Use fully qualified Java class names and exact overloads. Classes must be packaged into the APK and survive shrinking. AndroidRuntime.getApplicationContext() returns application context; it cannot replace an Activity when one is required. getActivity() can return null.

createRunnableFromReckfellCallable creates a Runnable but does not post it to the UI queue. The Callable runs on whichever thread invokes the Runnable. Proxies dispatch by method name: interfaces, parameters and return values must match.

For missing classes, check packaging and names. For invocation failures, check overloads, null values and threads. Do not retain stale Activities after recreation. JNI execution, callbacks and device-side C# access were not tested here.