我痛苦了3天。我使用兼容性库中的View Pager。我已经成功地显示了几个视图。我的问题是，当我交换视图时，不要在其回收站视图中按片段更新数据。但是当我关闭我的应用程序然后打开片段显示更新内容由recycler view.i使用所有方法，如setnotifydatachanged（）和更多，但viewpager中的Fragment不更新content.Thankx任何帮助 这是我的主要活动
public class MainActivity extends AppCompatActivity {
private ViewPager viewPager;
private TabLayout tabLayout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle("");
setSupportActionBar(toolbar);
viewPager = (ViewPager) findViewById(R.id.viewPager);
viewPager.setAdapter(new MainAdapter(getSupportFragmentManager(),MainActivity.this));
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
addIconsToTab();
}
private void addIconsToTab() {
for (int i = 0; i < tabLayout.getTabCount(); i++) {
int drwableId = -1;
switch (i) {
case 0:
drwableId = R.drawable.home;
break;
case 1:
drwableId = R.drawable.favourite;
break;
case 2:
drwableId = R.drawable.watchlater;
break;
}
tabLayout.getTabAt(i).setIcon(drwableId);
}
}
}
this is my main adapter
public class MainAdapter extends FragmentPagerAdapter {
Context mContext;
public MainAdapter(FragmentManager fm, Context context) {
super(fm);
mContext=context;
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new AllVideos();
case 1:
return new Favourite();
case 2:
return new WatchLater();
default:
return null;
}
}
@Override
public int getCount() {
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return mContext.getString(R.string.All_Videos);
case 1:
return mContext.getString(R.string.Favourite);
case 2:
return mContext.getString(R.string.Wtach_Later);
default:
return null;
}
}
@Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
}
And this is my Fragment
public class Favourite extends Fragment {
private RecyclerView mRecyclerView;
private FavouriteAdapter favouriteAdapter;
RecyclerView.LayoutManager layoutManager;
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_recyclerview_carpaccio, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mRecyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
layoutManager = new LinearLayoutManager(getActivity());
DatabaseHandler db = new DatabaseHandler(getActivity());
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerView.setHasFixedSize(true);
List<VideoInformationDataModel> videoinfo = db.getAllFavourite();
favouriteAdapter = new FavouriteAdapter(getActivity(),videoinfo);
mRecyclerView.setAdapter(favouriteAdapter);
favouriteAdapter.notifyDataSetChanged();
Toast.makeText(getActivity(),videoinfo.size()+"",Toast.LENGTH_SHORT).show();
}
}
And this is fragmentAdapter
public class FavouriteAdapter extends RecyclerView.Adapter<FavouriteAdapter.MyViewHolder>
{
private int[] maid = {R.id.deleteoption};
Context context;
private List<VideoInformationDataModel> videoInformationDataModels;
String videoid1;
private FavouriteAdapter favouriteAdapter;
public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public TextView title;
View root;
protected ImageLoader img_uni_imageLoader;
DatabaseHandler db = new DatabaseHandler(context);
ImageView networkImage,options;
TextView Duration,Videoname;
public MyViewHolder(View view) {
super(view);
root = itemView.findViewById(R.id.videoImage);
Duration= (TextView) itemView.findViewById(R.id.duration);
Videoname= (TextView) itemView.findViewById(R.id.VideoName);
networkImage= (ImageView) itemView. findViewById(R.id.imgNetwork);
options= (ImageView) itemView.findViewById(R.id.deleteoption);
options.setOnClickListener(this);
}
@Override
public void onClick(View view) {
if (maid[0] == view.getId()) {
PopupMenu popup = new PopupMenu(context, options);
popup.getMenuInflater().inflate(R.menu.deleteoption, popup.getMenu());
popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
@Override
public boolean onMenuItemClick(MenuItem menuItem) {
switch (menuItem.getItemId())
{
case R.id.delete:
int pos = getAdapterPosition () ;
videoid1= videoInformationDataModels.get(pos).getVideoid();
db.deleteFavourite(videoid1);
videoInformationDataModels.remove(pos);
notifyItemRemoved(pos);
notifyItemRangeChanged(pos, getItemCount());
return true;
}
return false;
}
});
popup.show();
}
}
}
public FavouriteAdapter(Context context, List<VideoInformationDataModel> videoinformation) {
this.videoInformationDataModels = videoinformation;
this.context=context;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.favouritesingleitem, parent, false);
return new MyViewHolder(itemView);
}
@Override
public void onBindViewHolder(MyViewHolder holder, final int position) {
holder.Duration.setText(videoInformationDataModels.get(position).getVideoduratio n());
holder.Videoname.setText(videoInformationDataModels.get(position).getVideoinfo() );
holder.img_uni_imageLoader = ImageLoader.getInstance();
.img_uni_imageLoader.init(ImageLoaderConfiguration.createDefault(context));
holder.img_uni_imageLoader.displayImage(videoInformationDataModels.get(position) .getVideoimg(), holder.networkImage);
holder.root.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(context, YouTube.class);
Bundle extras = new Bundle();
String Videtittle = videoInformationDataModels.get(position).getVideoinfo();
String videodes = videoInformationDataModels.get(position).getFld_description();
String duration = videoInformationDataModels.get(position).getVideoduration();
String videoid = videoInformationDataModels.get(position).getVideoid();
extras.putString("Videtittle", Videtittle);
extras.putString("videodes", videodes);
extras.putString("duration", duration);
extras.putString("videoid", videoid);
intent.putExtras(extras);
context.startActivity(intent);
}
});
}
@Override
public int getItemViewType(int position)
{
return position;
}
public int getItemCount() {
return videoInformationDataModels.size();
}
}
答案 0 :(得分：0)
我不太确定您面临的问题，但是您可以尝试通过FragmentStatePagerAdapter替换FragmentPagerAdapter（由MainAdapter扩展）。
答案 1 :(得分：0)
我没有清楚地理解你的问题是什么，这可能是错误实施的结果。但是，如果您尝试过favouriteAdapter.notifyDataSetChanged();，但仍然无法刷新。
您也可以移除视图，刷新视图并添加视图，看看是否有效。
ViewGroup parent = (ViewGroup) viewPager.getParent(); // get the view parent
if (parent != null) {
parent.removeView(viewPager); // remove the view
viewPager.getAdapter().notifyDataSetChanged(); // notify that the data has changed
parent.addView(viewPager); // then, re-add the view
}