我的应用程序有一个包含Fragment和视图寻呼机的活动。查看寻呼机实例化片段,在其中我从互联网加载数据并显示它。我有大约60个片段一直在查看寻呼机(日期:今天+30天前,30天后)。
问题是,当我改变方向时,数据会再次开始下载。如何保存这个片段的状态?
这是视图寻呼机适配器:
public class TimesheetPagerAdapter extends FragmentStatePagerAdapter {
private DateFormat dateFormat = new SimpleDateFormat("MM/dd/yyyy");
private DateFormat dateTitleFormatted = new SimpleDateFormat("MMM dd - EEEE", Locale.US);
private ArrayList<Date> mDates;
public TimesheetPagerAdapter(FragmentManager fm, ArrayList<Date> mDates) {
super(fm);
this.mDates = mDates;
}
@Override
public Fragment getItem(int i) {
return TimesheetPage.newInstance(dateFormat.format(mDates.get(i)));
}
@Override
public int getCount() {
return mDates.size();
}
}
和ViewPager片段:
public static TimesheetPage newInstance(String page) {
TimesheetPage TimesheetPage = new TimesheetPage();
Bundle arguments = new Bundle();
arguments.putString("date", page);
TimesheetPage.setArguments(arguments);
return TimesheetPage;
}
@Override
public void onCreate(Bundle savedInstanceState) {
setRetainInstance(true);
super.onCreate(savedInstanceState);
dateString = getArguments().getString("date");
Random rnd = new Random();
backColor = Color.argb(50, rnd.nextInt(256), rnd.nextInt(256), rnd.nextInt(256));
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.item_pager_timesheet, null);
LinearLayout layout = (LinearLayout) view.findViewById(R.id.llPageLayout);
tvPage = (TextView) view.findViewById(R.id.tvAmountHours);
mLoadingLayout = LoadingLayout.wrap(layout, android.R.attr.progressBarStyle);
lvTimesheet = (ListView) view.findViewById(R.id.lvTimesheet);
tvPage.setBackgroundColor(backColor);
long id = getController().getUserAccount().getCompany().getCompanyId();
mLoadingLayout.showLoading();
Log.i("onCreateView", "TimesheetPage" + dateString);
getController().getNetworkApi().getCompanyTimeSheet(id, dateString, timesheetCallback);
return view;
}
我建议您让片段重新创建,但将网络调用保存在应用程序缓存中,以避免每次都进行查询。您可以使用类似ion的库,该库使用磁盘+内存缓存:https://github.com/koush/ion