自定义适配器getView（）方法不叫 [英] Custom Adapter getView() method is not called
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问题描述
下面是在我设置一个自定义的适配器列表中的片段的code。有没有错误，但列表视图是空的。我已实施 getCount将（）返回我的ArrayList项目的权数。我坚持不好，请help.I没有看到（内部，GetView）在logcat中
片段
公共类ServiceCarListFragment扩展片段{
私人字符串URL;
私人的ArrayList＆LT; CarDetail＆GT; carDetailList =新的ArrayList＆LT; CarDetail＆GT;（）;
私人CarListAdapter适配器;
私人的ListView mList;
@覆盖
公共无效的onCreate（包savedInstanceState）{
// TODO自动生成方法存根
super.onCreate（savedInstanceState）;
网址= getActivity（）getIntent（）getStringExtra（URL）。;
新DownloadCarDetail（）执行（URL）;
}
@覆盖
公共查看onCreateView（LayoutInflater充气，容器的ViewGroup，
捆绑savedInstanceState）{
// TODO自动生成方法存根
视图V = inflater.inflate（R.layout.fragment_service_car_list，集装箱，假）;
mList =（ListView控件）v.findViewById（R.id.list）;
mList.setAdapter（适配器）;
对于（CarDetail车：carDetailList）{
//开始加载图像为每一个学生
car.loadImage（适配器）;
}
返回伏;
}
类DownloadCarDetail扩展的AsyncTask＆LT;字符串，字符串，ArrayList的＆LT; CarDetail＆GT;＆GT; {
@覆盖
受保护的ArrayList＆LT; CarDetail＆GT; doInBackground（字符串... PARAMS）{
// TODO自动生成方法存根
ArrayList的＆LT; CarDetail＆GT; carDetailList = JsonParser.parseJson（PARAMS [0]）;
返回carDetailList;
}
@覆盖
保护无效onPostExecute（ArrayList中＆LT; CarDetail＆GT; carDetailList）{
// TODO自动生成方法存根
ServiceCarListFragment.this.carDetailList = carDetailList;
Log.d（DCCS，将String.valueOf（ServiceCarListFragment.this.carDetailList.size（）））;
适配器=新CarListAdapter（getActivity（），ServiceCarListFragment.this.carDetailList）;
Log.d（DCCS，将String.valueOf（（adapter.getCount（））））;
}
}
CustomAdapter
公共类CarListAdapter扩展了BaseAdapter {
私人的ArrayList＆LT; CarDetail＆GT;项目=新的ArrayList＆LT; CarDetail＆GT;（）;
私人上下文的背景下;
公共CarListAdapter（上下文的背景下，ArrayList的＆LT; CarDetail＆GT;项目）{
this.context =背景;
this.items =项目;
}
@覆盖
公众诠释getCount将（）{
// TODO自动生成方法存根
返回items.size（）;
}
@覆盖
公共对象的getItem（INT位置）{
// TODO自动生成方法存根
返回items.get（位置）;
}
@覆盖
众长getItemId（INT位置）{
// TODO自动生成方法存根
返回的位置;
}
@覆盖
公共查看getView（INT位置，查看convertView，ViewGroup中父）{
// TODO自动生成方法存根
Log.d（内部，GetView）;
LayoutInflater mInflater =（LayoutInflater）context.getSystemService（Activity.LAYOUT_INFLATER_SERVICE）;
ViewHolder支架=无效;
CarDetail车= items.get（位置）;
如果（convertView == NULL）{
convertView = mInflater.inflate（R.layout.car_list_row，NULL）;
持有人=新ViewHolder（）;
holder.tvCarName =（TextView中）convertView.findViewById（R.id.tvCarName）;
holder.tvDailyPriceValue =（TextView中）convertView.findViewById（R.id.tvWeeklyPriceValue）;
holder.tvWeeklyPriceValue =（TextView中）convertView.findViewById（R.id.tvWeeklyPriceValue）;
holder.imgCar =（ImageView的）convertView.findViewById（R.id.imgCar）;
convertView.setTag（保持器）;
}
其他 {
支架=（ViewHolder）convertView.getTag（）;
}
holder.tvCarName.setText（car.getCarName（））;
如果（car.getImage（）！= NULL）{
holder.imgCar.setImageBitmap（car.getImage（））;
} 其他 {
//我的默认图片
holder.imgCar.setImageResource（R.drawable.ic_action_call）;
}
返回convertView;
}
静态类ViewHolder {
TextView的tvCarName;
TextView的tvDailyPriceValue;
TextView的tvWeeklyPriceValue;
ImageView的imgCar;
}
}
解决方案
的唯一原因 getView 不叫有：
-
getCount将返回0 - 您忘了叫
setListAdapter在的ListView。 - 如果在
的ListView的可见性（或它的容器的可见性）是GONE。感谢@TaynãBonaldo的宝贵意见
在 onPostExcute ，之后创建 CarListAdapter 的新实例，我会建议您更新了新的实例你的的ListView 。事实上，你需要再次调用
mList.setAdapter（适配器）;
Here is the code of the fragment in which I am setting a custom adapter to the list. There no errors but the list view is empty. I have implemented getCount() which returns right number of items in my arraylist. I am stuck badly please help.I dont see ("Inside", "GetView") in the logcat
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())));
}
}
CustomAdapter
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;
}
}
解决方案
the only reasons getView is not called are:
getCountreturns 0- you forget to call
setListAdapteron theListView. - If the
ListView's visibility (or its container's visibility) isGONE. Thanks to @TaynãBonaldo for the valuable input
In the onPostExcute, after you create a new instance of CarListAdapter I will suggest you to update the new instance to your ListView. Indeed you need to call again
mList.setAdapter(adapter);
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