For some reason I can only call native functions from my main activity and not any custom views that I've created. Here is an example file (I followed a tutorial, but renamed the classes http://mindtherobot.com/blog/452/android-beginners-ndk-setup-step-by-step/)

See the usage of the native function "getNewString".

package com.example.native;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.os.Bundle;
import android.view.View;

public class NativeTestActivity extends Activity
{   
    static
    {
        System.loadLibrary("nativeTest");
    }

    private native String getNewString();

    @Override public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);        
        this.setContentView(new BitmapView(this));

        String hello = getNewString(); // This line works fine
        new AlertDialog.Builder(this).setMessage(hello).show();
    }
}

class BitmapView extends View
{
    static
    {
        System.loadLibrary("nativeTest");
    }

    private native String getNewString();

    public BitmapView(Context context)
    {
        super(context);

        String hello = getNewString(); // This line throws the UnsatisfiedLinkError
        new AlertDialog.Builder(this.getContext()).setMessage(hello).show();
    }
}

How can I call native functions in my custom views?

I've built the application as an Android 2.2 app. I'm running the application on my HTC Desire. I have the latest SDK (9) and latest NDK (r5).