What context should I use when sending an Intent to an activity in a separate DEX file?

Question

I have an android activity located in a separate dex file that I want to launch from my android app. I get an exception after starting the intent.

Didn't find class "com.example.testproject.SampleActivity" on path: /data/app/com.example.testproject.apk

I built an activity class and let Eclipse put it in a dex file

public class SampleActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //setContentView(R.layout.activity_sample);
    setContentView(getIntent().getIntExtra("LAYOUT", -1));

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.sample, menu);
    return true;
}

}

I added that activity to my main apps manifest file

    <activity
        android:name="com.example.testproject.SampleActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity> 

I also added the activity_sample.xml layout file to my main apps project so I could pass it via the Intent to the other activity

then from the main app I build an intent to call the other activity as follows

            String p = Environment.getExternalStorageDirectory().getPath() + "/classes.dex";
            ClassLoader dexLoader = new DexClassLoader(p, getCacheDir().getAbsolutePath(), null, getClassLoader());

            try {
                Class<?> activityClass = dexLoader.loadClass("com.example.testproject.SampleActivity"); 
                Intent intent = new Intent(Intent.ACTION_MAIN);
                intent.setClass(getApplicationContext(), activityClass);
                intent.putExtra("LAYOUT", R.layout.activity_sample);
                startActivity(intent);
                finish();  

            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

the class is loaded okay but after calling startActivity() I get the exception noted above. This seems to the a problem with the context of the intent since the exception shows the class is being looked for in /data/app/com.example.testproject.apk which it is not in the apk (the dex file is on the sd card).

Any ideas how to resolve this issue?

Answer 1

This won't work. The activities that are specified in the AndroidManifest.xml of an apk must be defined in the main classes.dex of that apk.