So starten Sie eine Aktivität aus einem dialog?

Irgendwelche Ideen, wie man starten Sie eine Aktivität und senden eines Wertes aus einem dialog button?

Hier ist, was ich im moment haben. Habe versucht eine Reihe von Variationen, aber die app stürzt ab, wenn die Taste gedrückt wird:

dialog.setPositiveButton("View Profile", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog, int which) {
        Intent intent = new Intent();
        intent.setClass(context, Profile.class);
        intent.putExtra("profileID",  "8");            
        startActivity(intent);
        dialog.cancel();
        return;
    } 
});

Voll Klasse:

public class PlacesItemizedOverlay extends ItemizedOverlay {
    private Context context;
    private ArrayList<OverlayItem> items = new ArrayList<OverlayItem>();
    private Activity aClass;

    public PlacesItemizedOverlay(Context aContext, Drawable marker) {
        super(boundCenterBottom(marker));
        context = aContext;
    }

    public void addOverlayItem(OverlayItem item) {
        items.add(item); 
        populate();
    }

    @Override
    protected OverlayItem createItem(int i) {
        return (OverlayItem) items.get(i);
    }

    @Override
    public int size() {
        return items.size();
    }

    @Override
    protected boolean onTap(int index) {
        aClass = new Activity();
        OverlayItem item = (OverlayItem) items.get(index);
        if(item.getTitle() != null)
            {
            AlertDialog.Builder dialog = new AlertDialog.Builder(context);
            dialog.setTitle(item.getTitle());
            dialog.setPositiveButton("View Profile",
                    new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface dialog, int which) {
                    Intent intent = new Intent();
                    intent.setClass(context, Profile.class);
                    intent.putExtra("profileID",  "8");            
                    aClass.startActivity(intent);
                    dialog.cancel();
                    return;
                } 
            });
            dialog.show();
        }
        return true;
    }
}

LogCat:

06-24 10:35:31.253: WARN/dalvikvm(30118): threadid=1: thread exiting with uncaught exception (group=0x4001d5a0)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118): FATAL EXCEPTION: main
06-24 10:35:31.283: ERROR/AndroidRuntime(30118): java.lang.NullPointerException
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at android.app.Activity.startActivityForResult(Activity.java:2901)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at android.app.Activity.startActivity(Activity.java:3007)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at com.example.android.test.PlacesItemizedOverlay$1.onClick(PlacesItemizedOverlay.java:57)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:159)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at android.os.Handler.dispatchMessage(Handler.java:99)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at android.os.Looper.loop(Looper.java:143)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at android.app.ActivityThread.main(ActivityThread.java:4196)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at java.lang.reflect.Method.invokeNative(Native Method)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at java.lang.reflect.Method.invoke(Method.java:507)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
06-24 10:35:31.283: ERROR/AndroidRuntime(30118):     at dalvik.system.NativeStart.main(Native Method)
06-24 10:35:31.293: WARN/ActivityManager(1344):   Force finishing activity com.example.android.test/.SearchActivity