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我有一个有效的应用程序。现在我想修改它以使用ViewPager。我的意思是，我已经定义了一个新活动，我想使用ViewPager在活动之间滑动。为了做到这一点，我将原始活动转换为片段。这是原始（简化）代码

public class ListViewImagesActivity extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    ArrayList<Fish> image_details = populateList();

    final ListView lv1 = (ListView) findViewById(R.id.listV_main);
    final ItemListBaseAdapter ilba = new ItemListBaseAdapter(this, image_details);
    lv1.setAdapter(ilba);

    lv1.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> a, View v, int position, long id) {
            Object o = lv1.getItemAtPosition(position);
            Fish obj_itemDetails = (Fish) o;

            Intent intent = new Intent(ListViewImagesActivity.this, DisplayFishDetailActivity.class);

            startActivity(intent);
        }
    });
}

}

我已经通过以下方式修改了代码。

import android.support.v4.app.Fragment;
public class ListViewImagesActivity extends Fragment {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstancesState) {
    return inflater.inflate(R.layout.activity_display_fish_detail, container, false);
}

@Override
public void onStart() {
    super.onStart();

    ArrayList<Fish> image_details = populateList();

    final ListView lv1 = (ListView) getView().findViewById(R.id.pager);
    final ItemListBaseAdapter ilba = new ItemListBaseAdapter(getActivity(), image_details);
    lv1.setAdapter(ilba);

    lv1.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> a, View v, int position, long id) {
            Object o = lv1.getItemAtPosition(position);
            Fish obj_itemDetails = (Fish) o;

            Intent intent = new Intent(getActivity(), DisplayFishDetailActivity.class);

            startActivity(intent);
        }
    });
}

现在，适配器ItemListBaseAdapter使用getActivity()而不是this接收上下文（实际上我不确定这是否正确）。运行应用程序时，我在lv1.setAdapter(ilba)处遇到空指针异常。

有什么提示吗？

提前致谢

4

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