这是我为列表设置自定义适配器的 fragment 的代码。
没有错误,但 ListView
为空。我已经实现了 getCount()
,它在我的 ArrayList 中返回正确数量的项目。我在 logcat 中没有看到 ("Inside", "GetView")
fragment
public class ServiceCarListFragment extends Fragment {
private String url;
private ArrayList<CarDetail> carDetailList = new ArrayList<CarDetail>();
private CarListAdapter adapter;
private ListView mList;
@Override
public void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
url = getActivity().getIntent().getStringExtra("url");
new DownloadCarDetail().execute(url);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
View v = inflater.inflate(R.layout.fragment_service_car_list, container, false);
mList = (ListView) v.findViewById(R.id.list);
mList.setAdapter(adapter);
for (CarDetail car : carDetailList) {
// START LOADING IMAGES FOR EACH STUDENT
car.loadImage(adapter);
}
return v;
}
class DownloadCarDetail extends AsyncTask<String, String, ArrayList<CarDetail>> {
@Override
protected ArrayList<CarDetail> doInBackground(String... params) {
// TODO Auto-generated method stub
ArrayList<CarDetail> carDetailList = JsonParser.parseJson(params[0]);
return carDetailList;
}
@Override
protected void onPostExecute(ArrayList<CarDetail> carDetailList) {
// TODO Auto-generated method stub
ServiceCarListFragment.this.carDetailList = carDetailList;
Log.d("dccs", String.valueOf(ServiceCarListFragment.this.carDetailList.size()));
adapter = new CarListAdapter(getActivity(), ServiceCarListFragment.this.carDetailList);
Log.d("dccs", String.valueOf((adapter.getCount())));
}
}
}
自定义适配器
public class CarListAdapter extends BaseAdapter {
private ArrayList<CarDetail> items = new ArrayList<CarDetail>();
private Context context;
public CarListAdapter(Context context, ArrayList<CarDetail> items) {
this.context = context;
this.items = items;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return items.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return items.get(position);
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
Log.d("Inside", "GetView");
LayoutInflater mInflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
ViewHolder holder = null;
CarDetail car = items.get(position);
if (convertView == null) {
convertView = mInflater.inflate(R.layout.car_list_row, null);
holder = new ViewHolder();
holder.tvCarName = (TextView) convertView.findViewById(R.id.tvCarName);
holder.tvDailyPriceValue = (TextView) convertView.findViewById(R.id.tvWeeklyPriceValue);
holder.tvWeeklyPriceValue = (TextView) convertView.findViewById(R.id.tvWeeklyPriceValue);
holder.imgCar = (ImageView) convertView.findViewById(R.id.imgCar);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.tvCarName.setText(car.getCarName());
if (car.getImage() != null) {
holder.imgCar.setImageBitmap(car.getImage());
} else {
// MY DEFAULT IMAGE
holder.imgCar.setImageResource(R.drawable.ic_action_call);
}
return convertView;
}
static class ViewHolder {
TextView tvCarName;
TextView tvDailyPriceValue;
TextView tvWeeklyPriceValue;
ImageView imgCar;
}
}
最佳答案
getView
未被调用的唯一原因是:
getCount
返回 0。- 您忘记在
ListView
上调用setAdapter
。 - 如果
ListView
的可见性(或其容器的可见性)为GONE
。感谢@TaynãBonaldo 提供的宝贵意见。 ListView
未附加到任何视口(viewport)布局。即mListView = new ListView(...)
不使用myLayout.addView(mListView)
。
在 onPostExcute
中,在您创建 CarListAdapter
的新实例后,我建议您将新实例更新到您的 ListView
。确实需要再打电话
mList.setAdapter(adapter);
编辑:setAdapter
应始终在 ui 线程上调用,以避免意外行为
编辑2:
这同样适用于 RecyclerView
。确保
getItemCount
返回的值大于0
(通常是数据集大小)setLayoutManager
和setAdapter
都必须在UI 线程
上调用
- 小部件的可见性必须设置为
VISIBLE
关于android - 未调用自定义适配器 getView() 方法,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/16338281/