我无法使用新数据刷新ListFragment中的ListView。而是将新数据添加到上一个数据中。
每个实体的时间段从早上6点到下午5点。然后将新数据附加到在早上6点为另一个实体重新启动的列表中。在将第二个实体添加到ListView之前，应清除第一个实体的数据。
以下是代码：
public class FragmentStatePagerSupport extends FragmentActivity {
static final int NUM_ITEMS = 4; //control number of fragments
MyAdapter mAdapter;
ViewPager mPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_main);
mAdapter = new MyAdapter(getSupportFragmentManager());
mPager = (ViewPager)findViewById(R.id.pager);
mPager.setAdapter(null);
mPager.setAdapter(mAdapter);
}
//===============================================================================================
public static class MyAdapter extends FragmentStatePagerAdapter {
public MyAdapter(FragmentManager fm) {
super(fm);
}
@Override
public int getCount() {
return NUM_ITEMS;
}
@Override
public Fragment getItem(int position) {
fragNumber = position;
return ArrayListFragment.newInstance(position);
}
}
//===============================================================================================
public static class ArrayListFragment extends ListFragment {
Integer mNum;
String FORMAT_LINE = "%s%7s%7s%10s%16s";
static ArrayListFragment newInstance(int num) {
ArrayListFragment f = new ArrayListFragment();
Bundle args = new Bundle();
args.putInt("num", num);
f.setArguments(args);
return f;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mNum = getArguments() != null ? getArguments().getInt("num") : 1;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_pager_list, container, false);
View tv = v.findViewById(R.id.text);
View tvd = v.findViewById(R.id.tv_description);
String title = "";
switch (mNum){
case 0:title = MyGlobals.getInstance().getToday();break;
case 1:title = MyGlobals.getInstance().getTomorrow();break;
case 2:title = MyGlobals.getInstance().getDayAfter();break;
case 3:title = MyGlobals.getInstance().getDayDayAfter();break;
}
((TextView) tv).setText(MyGlobals.getInstance().getName() + " on " + title);
((TextView) tvd).setText(String.format(FORMAT_LINE, "time", "temp", "rain", "wind", "weather"));
return v;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
ArrayList<Data> row = Data.getRows(mNum);
ListViewAdapter adapter = new ListViewAdapter(getActivity(), row);
getListView().setAdapter(null);
getListView().setAdapter(adapter);
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
v.setBackgroundColor(getResources().getColor(R.color.blue));
}
}
//==============================================================================================
public static class ListViewAdapter extends ArrayAdapter<Data> {
public static class ViewHolder{
TextView time;
TextView temp;
TextView rain;
TextView wind_speed;
TextView weather;
}
public ListViewAdapter(Context context, ArrayList<Data> list) {super(context, R.layout.text_listview, list); }
@Override
public View getView(int position, View convertView, ViewGroup parent) {
Data data = getItem(position);
ViewHolder holder;
if(convertView == null){
holder=new ViewHolder();
LayoutInflater inflater = LayoutInflater.from(getContext());
convertView=inflater.inflate(R.layout.text_listview,parent,false);
holder.time=(TextView) convertView.findViewById(R.id.time);
holder.temp=(TextView) convertView.findViewById(R.id.temp);
holder.rain=(TextView) convertView.findViewById(R.id.rain);
holder.wind_speed=(TextView) convertView.findViewById(R.id.wind);
holder.weather=(TextView) convertView.findViewById(R.id.weather);
convertView.setTag(holder);
}else{
holder=(ViewHolder) convertView.getTag();
}
holder.time.setText(data.time);
holder.temp.setText(data.temp);
holder.rain.setText(data.rain);
holder.wind_speed.setText(data.wind_speed);
holder.weather.setText(data.weather);
return convertView;
}
}
}
这最后一部分填充了ListView。调用adapter.clear（）和adapter.notifyDataSetChanged（）不能解决问题。
3年前有一个类似的问题How update ListView in ListFragment from FragmentActivity?尽管有6836次观看，仍然没有被接受的答案。
非常感谢。
请求的GetRows（mNum）部分：
public class Data {
public String time;
public String temp;
public String rain;
public String wind_speed;
public String weather;
public Data(String time, String temp, String rain, String wind_speed, String weather) {
this.time = time;
this.temp = temp;
this.rain = rain;
this.wind_speed = wind_speed;
this.weather = weather;
}
public static ArrayList<Data> getRows(int fragNumber) {
int mNum = fragNumber;
int size;
String myList[] = null;
ArrayList<Data> list = new ArrayList<Data>();
switch (mNum) {
case 0://Today
size = MyGlobals.getInstance().getToday("time").size();
myList = new String[size];
for (int i = 0; i < size; i++) {
String time = (String) MyGlobals.getInstance().getToday("time").get(i);
String temp = (String) MyGlobals.getInstance().getToday("temperature").get(i);
String wind_speed = (String) MyGlobals.getInstance().getToday("wind_speed").get(i);
String pop = (String) MyGlobals.getInstance().getToday("pop").get(i);
//String wind_gust = (String) MyGlobals.getInstance().getToday("wind_gust").get(i); //when null breaks code
String weather = (String) MyGlobals.getInstance().getToday("weather").get(i);
if (time.length() == 4) time = "0" + time;
if (wind_speed.length() == 1) wind_speed = "0" + wind_speed;
if (pop.length() == 1) pop = "0" + pop;
list.add(new Data(time,temp,pop,wind_speed,weather));
}
return list;
case 1://Tomorrow
...snip... same as above with pertinent variables,...
case 2://DayAfter
...snip...
case 3://DayDayAfter
...snip....
case 4:// is an error
Log.d("***error***", "list got to case 5");
}
return list;
}
}
答案 0 :(得分：0)
试试这个;
通知新数据的适配器，即adapter.notifyDataSetChanged（）
您在getRows（）
删除案例结构
之前的“返回列表”public void onActivityCreated（Bundle savedInstanceState） { super.onActivityCreated（savedInstanceState）; //在添加新列表之前清除旧列表。 if（list！= null） { list.clear（）; } //添加新列表
list = Data.getRows（mNum）; ListViewAdapter适配器=新 ListViewAdapter（getActivity（），list）; getListView（）setAdapter（适配器）。 adapter.notifyDataSetChange（）; }