Activity Wechsel funktioniert nicht richtig

1...
2lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
3
4 @Override
5 public void onItemClick(AdapterView<?> arg0, View view, int pos,
6 long id) {
7 Log.i(TAG, "Selected Item is = "+lv.getItemAtPosition(pos));
8 Toast.makeText(Seperator.this, lv.getItemAtPosition(pos).toString(), Toast.LENGTH_SHORT).show();
9
10 if(id == 3){
11 Intent intent = new Intent(Seperator.this, GridActivity.class);
12 intent.putExtra("cat", "70-0520");
13 startActivity(intent);
14 finish();
15 }
16 }
17 });
18...

1public class GridActivity extends Activity{
2
3 private final String TAG = "GridActivity";
4 private GridView gridview;
5
6 @Override
7 protected void onCreate(Bundle savedInstanceState) {
8 super.onCreate(savedInstanceState);
9 setContentView(R.layout.grid);
10
11 Log.i(TAG, "Here");
12 gridview = (GridView) findViewById(R.id.gridview);
13 gridview.setAdapter(new ImageAdapter(GridActivity.this));
14 }
15
16}

1public class ImageAdapter extends BaseAdapter {
2
3 private Context context;
4 private Integer[] mThumbIds = {
5 R.drawable.mag, R.drawable.mag,
6 R.drawable.mag, R.drawable.mag,
7 R.drawable.mag, R.drawable.mag,
8 R.drawable.mag, R.drawable.mag,
9 R.drawable.mag, R.drawable.mag,
10 R.drawable.mag, R.drawable.mag
11 };
12
13 public ImageAdapter(Context context){
14 this.context = context;
15 }
16
17 @Override
18 public int getCount() {
19 return 0;
20 }
21
22 @Override
23 public Object getItem(int position) {
24 return null;
25 }
26
27 @Override
28 public long getItemId(int position) {
29 return 0;
30 }
31
32 @Override
33 public View getView(int position, View convertView, ViewGroup parent) {
34 ImageView imageView;
35 if (convertView == null) { // if it's not recycled, initialize some attributes
36 imageView = new ImageView(context);
37 imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
38 imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
39 imageView.setPadding(8, 8, 8, 8);
40 } else {
41 imageView = (ImageView) convertView;
42 }
43
44 imageView.setImageResource(mThumbIds[position]);
45 return imageView;
46 }
47}

1<?xml version="1.0" encoding="utf-8"?>
2<GridView
3 xmlns:android="http://schemas.android.com/apk/res/android"
4 android:id="@+id/gridview"
5 android:layout_width="fill_parent"
6 android:layout_height="fill_parent"
7 android:numColumns="auto_fit"
8 android:verticalSpacing="10dp"
9 android:horizontalSpacing="10dp"
10 android:columnWidth="90dp"
11 android:stretchMode="columnWidth"
12 android:gravity="center" />