Android 当我在asynctask中调用notifydatasetchanged时，我的Recyclerview滚动到顶部

当我在asynctask中调用notifydatasetchanged时，我的Recyclerview滚动到顶部 如何停止滚动到顶部，这是LoadrsFeedSitems异步任务中的问题

我的回收视图

    @Override
    public void onCreate(Bundle savedInstanceState) {       
        super.onCreate(savedInstanceState);   
        Log.i(TAG_LIFE, "Inside onCreat");    
    }

    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        Log.i(TAG_LIFE, "Inside onViewCreated");
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.head_line_fragment, container, false);
        Log.i(TAG_LIFE, "Inside onCreateView");
        view = rootView;
        mRecyclerView = (RecyclerView) rootView.findViewById(R.id.recycler_view);
        mLayoutManager = new LinearLayoutManager(getActivity());    

        if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {

            mCurrentLayoutManagerType = LayoutManagerType.LINEAR_LAYOUT_MANAGER;
        } else {
            mCurrentLayoutManagerType = LayoutManagerType.GRID_LAYOUT_MANAGER;
        }

        if (savedInstanceState != null) {
            mDataset = savedInstanceState.getParcelableArrayList(Constants.MY_DATA_SET_KEY);
            mAdapter = new RecyclerAdapter(mDataset);
            mRecyclerView.setAdapter(mAdapter);
        }
        setRecyclerViewLayoutManager(mCurrentLayoutManagerType);
        return rootView;
    }

    public void setRecyclerViewLayoutManager(LayoutManagerType layoutManagerType) {
        int scrollPosition = 0;
        if (mRecyclerView.getLayoutManager() != null) {
            scrollPosition = ((LinearLayoutManager) mRecyclerView.getLayoutManager())
                    .findFirstCompletelyVisibleItemPosition();
        }

        switch (layoutManagerType) {
            case GRID_LAYOUT_MANAGER:
                mLayoutManager = new GridLayoutManager(getActivity(), SPAN_COUNT);
                mCurrentLayoutManagerType = LayoutManagerType.GRID_LAYOUT_MANAGER;
                break;
            case LINEAR_LAYOUT_MANAGER:
                mLayoutManager = new LinearLayoutManager(getActivity());
                mCurrentLayoutManagerType = LayoutManagerType.LINEAR_LAYOUT_MANAGER;
                break;
            default:
                mLayoutManager = new LinearLayoutManager(getActivity());
                mCurrentLayoutManagerType = LayoutManagerType.LINEAR_LAYOUT_MANAGER;
        }

        mRecyclerView.setLayoutManager(mLayoutManager);
        mRecyclerView.scrollToPosition(scrollPosition);
    }

    @Override
    public void onSaveInstanceState(Bundle savedInstanceState) {

        savedInstanceState.putSerializable(KEY_LAYOUT_MANAGER, mCurrentLayoutManagerType);
        savedInstanceState.putParcelableArrayList(Constants.MY_DATA_SET_KEY, mDataset);
        super.onSaveInstanceState(savedInstanceState);
    }

    @Override
    public void setUserVisibleHint(boolean isVisibleToUser) {
        super.setUserVisibleHint(isVisibleToUser);

        if (isVisibleToUser && mDataset.isEmpty()) {
            Log.i(TAG_LIFE, "setUserVisibleHint");
            new LoadRssFeedsItems().execute(Constants.HEALTH);
        }
        this.isVisibleToUser=isVisibleToUser;
        Log.i(TAG_LIFE,"setUserVisibleHint"+String.valueOf(this.isVisibleToUser));

    }   

    private enum LayoutManagerType {
        GRID_LAYOUT_MANAGER,
        LINEAR_LAYOUT_MANAGER
    }

    public class LoadRssFeedsItems extends AsyncTask<String, Void, String> {
        int i = 0;  

        private final String Not_interasted_catguty_in_Cutture = mySharedPreferences.loadStringPrefs(Constants.REMOVE_KEY_CULTURE_CATEGORY, "N/A", MainActivity.context);
        private final String Not_interasted_catguty_in_Since = mySharedPreferences.loadStringPrefs(Constants.REMOVE_KEY_SINCE_CATEGORY, "N/A", MainActivity.context);
        private final String Not_interasted_catguty_in_Sport= mySharedPreferences.loadStringPrefs(Constants.REMOVE_KEY_SPORT_CATEGORY, "N/A", MainActivity.context);
        private final String Not_interasted_catguty_in_Socity= mySharedPreferences.loadStringPrefs(Constants.REMOVE_KEY_SOCITY_CATEGORY, "N/A", MainActivity.context);   

        public LoadRssFeedsItems() {
        }

        protected String doInBackground(String... urls) {
            try {
                Document rssDocument = Jsoup.connect(urls[0]).timeout(Constants.BIG_TIME_OUT).ignoreContentType(true).parser(Parser.xmlParser()).get();
                Elements mItems = rssDocument.select(Constants.ITEM);
                RssItem rssItem;
                for (Element element : mItems) {
                    mTitle = element.select("title").first().text();
                    mDescription = element.select("description").first().text();
                    mLink = element.select("link").first().text();
                    mPubDate = element.select("pubDate").first().text();
                    mCatgury = element.select("category").first().text();
                    Log.i(TAG, "Item title: " + (mTitle == null ? "N/A" : mTitle));
                    Log.i(TAG, "Item Description: " + (mDescription == null ? "N/A" : mDescription));
                    Log.i(TAG, "Item link: " + (mLink == null ? "N/A" : mLink));
                    Log.i(TAG, "Item data: " + (mPubDate == null ? "N/A" : mPubDate));
                    Log.i(TAG, "Item image link: " + (mImageURL == null ? "N/A" : mImageURL));

                    Log.i(TAG,mCatgury);
                    if(mCatgury.equals("مہاجرین کا بحران"))
                    {
                        continue;
                    }
                    rssItem = new RssItem(mTitle, mDescription, mPubDate, mLink, mCatgury, i, getActivity());
                    mDataset.add(rssItem);    
                }    

            } catch (Exception e) {
                e.printStackTrace();
            }
            return "d";
        }

        protected void onPostExecute(String result) {    

            if ((CultureFlag && !mDataset.isEmpty()) || SportFlag || SinceFlag || socityFlag) {

                if(CultureFlag)
                {
                    if(mDataset.get(mDataset.size()-1).getCategory().equals("فن و ثقافت"))
                    {
                        Log.i(TAGi,"mDataset.get(mDataset.size()-1).getCategory().equals(\"فن و ثقافت\")");

                        CultureFlag=false;
                        SportFlag=true;

                    }
                    else {
                        Log.i(TAGi,"mDataset.get(mDataset.size()-1).getCategory().equals(\"فن و ثقافت\") else part");    

                    }
                }else  if(SportFlag)
                {
                    if(mDataset.get(mDataset.size()-1).getCategory().equals("کھیل"))
                    {

                        Log.i(TAGi,"mDataset.get(mDataset.size()-1).getCategory().equals(\"کھیل\")");
                        SportFlag=false;
                        SinceFlag=true;

                    }else {

                    }
                }else  if(SinceFlag)
                {
                    if(mDataset.get(mDataset.size()-1).getCategory().equals("سائنس اور ماحول"))
                    {
                        Log.i(TAGi,"mDataset.get(mDataset.size()-1).getCategory().equals(\"سائنس اور ماحول\")");
                        SinceFlag=false;
                        socityFlag=true;

                    }
                }else if(socityFlag)
                {
                    if(mDataset.get(mDataset.size()-1).getCategory().equals("معاشرہ"))
                    {
                        Log.i(TAGi,"mDataset.get(mDataset.size()-1).getCategory().equals(\"معاشرہ\")");
                        socityFlag=false;    
                    }
                }    
            }    

            if(!mDataset.isEmpty() && mDataset.get(mDataset.size()-1).getCategory().equals("صحت"))
            {
                CultureFlag=true;
            }

            if (CultureFlag) {    

                Log.i(TAGi, " CultureFlag");
                if (Not_interasted_catguty_in_Cutture.equals("N/A"))
                {    
                    new LoadRssFeedsItems().execute(Constants.ART_AND_CULTURE);

                }
                else
                {
                    SportFlag = true;
                    CultureFlag=false;
                }

            }
            if (SportFlag) {    

               if(Not_interasted_catguty_in_Sport.equals("N/A"))
               {
                   Log.i(TAGi, " SportFlag");
                   new LoadRssFeedsItems().execute(Constants.SPORT);
               }else{
                   SinceFlag = true;
                   SportFlag=false;    
               }    
            }
            if (SinceFlag) {
                if(Not_interasted_catguty_in_Since.equals("N/A"))
                {
                    Log.i(TAGi, " SinceFlag");
                    new LoadRssFeedsItems().execute(Constants.SCIENCE_AND_ENVIMENT);
                }else {
                    SinceFlag=false;
                    socityFlag=true;
                }    
            }

            if(socityFlag)
            {
                if(Not_interasted_catguty_in_Socity.equals("N/A"))
                {
                    new LoadRssFeedsItems().execute(Constants.SOCIETY);
                }
                else {
                    socityFlag=false;
                }
            }


            if (mDataset.isEmpty()) {
                try {
                    Snackbar mSnackbar = Snackbar.make(view, "Unable to connect", Snackbar.LENGTH_INDEFINITE)
                            .setAction("RETRY", new View.OnClickListener() {
                                @Override
                                public void onClick(View view) {

                                    new LoadRssFeedsItems().execute(Constants.HEALTH);    
                                }
                            });
                    mSnackbar.show();
                } catch (NullPointerException n) {

                }
            }else if(mDataset.isEmpty() && mDataset.get(mDataset.size()-1).getCategory().equals("صحت"))
            {    
                mAdapter.notifyDataSetChanged();
            }
            else {
                mAdapter = new RecyclerAdapter(mDataset);
                Log.i(TAGi, "m data set size: " + mDataset.size());

                mRecyclerView.setAdapter(mAdapter);
                mAdapter.notifyDataSetChanged();
                if (!new MySharedPreferences().loadPrefs(Constants.switchStateKey, true, MainActivity.context)) {
                    getImageUrls get_ImageUrls = new getImageUrls();
                    get_ImageUrls.execute();
                }
            }
        }
    }

    private class getImageUrls extends AsyncTask<Void, Void, Void> {
        String mLink;
        String mLastHalfUrl;
        String url;
        int dash_A_index;

        @Override
        protected Void doInBackground(Void... params) {

            Log.i(TAG, "Item image link in seacond thread: " + (mImageURL == null ? "N/A" : mImageURL));
            try {
                for (int i = 0; i < mDataset.size(); i++) {
                    mLink = mDataset.get(i).getPostLink();
                    dash_A_index = mLink.indexOf(Constants.BACK_SLASH_A);
                    mLastHalfUrl = mLink.substring(dash_A_index);
                    url = mLink.replace(Constants.BASE_URL, "");
                    url = url.replace(mLastHalfUrl, "");
                    url = StringUtils.replaceEach(URLEncoder.encode(url, "UTF-8"), new String[]{"+", "*", "%7E"}, new String[]{"%20", "%2A", "~"});
                    StringBuilder sb = new StringBuilder(url);
                    url = sb.append(mLastHalfUrl).toString();
                    url = Constants.BASE_URL + url;
                    documentImage = Jsoup.connect(url).get();
                    metalinks = documentImage.select(Constants.MATA_PROPTY_IMAGE);
                    mImageURL = metalinks.attr(Constants.CONTENT);
                    Log.i(TAG, "Item image link in seacond thread: " + (mImageURL == null ? "N/A" : mImageURL));
                    mDataset.get(i).setImageUrl(mImageURL);    
                }

            } catch (Exception e) {

            }
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {    
            mAdapter.notifyDataSetChanged();
        }
    }    
}

@覆盖
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
Log.i（TAG_LIFE，“内部onCreat”）；
}
@凌驾
已创建视图上的公共void（视图，@Nullable Bundle savedInstanceState）{
super.onViewCreated（视图，savedInstanceState）；
Log.i（TAG_LIFE，“内部onViewCreated”）；
}
@凌驾
CreateView上的公共视图（布局、充气机、视图组容器、捆绑包保存状态）{
视图根视图=充气机。充气（R.layout.head\u line\u碎片，容器，假）；
Log.i（TAG_LIFE，“内部onCreateView”）；
视图=根视图；
mRecyclerView=（RecyclerView）rootView.findviewbyd（R.id.recycler\u视图）；
mLayoutManager=新的LinearLayoutManager（getActivity（））；
if（getResources（）.getConfiguration（）.orientation==Configuration.orientation\u纵向）{
mCurrentLayoutManagerType=LayoutManagerType.LINEAR\u LAYOUT\u MANAGER；
}否则{
mCurrentLayoutManagerType=LayoutManagerType.GRID\u LAYOUT\u MANAGER；
}
如果（savedInstanceState！=null）{
mDataset=savedInstanceState.getParcelableArrayList（Constants.MY_DATA_SET_KEY）；
mAdapter=新的回收适配器（mDataset）；
mRecyclerView.setAdapter（mAdapter）；
}
SetRecycleServiceWLayoutManager（mCurrentLayoutManagerType）；
返回rootView；
}
公共void setRecycleServiceWLayoutManager（LayoutManagerType LayoutManagerType）{
int-scrollPosition=0；
if（mRecyclerView.getLayoutManager（）！=null）{
scrollPosition=（（LinearLayoutManager）MRECyclView.getLayoutManager（））
.findFirstCompletelyVisibleItemPosition（）；
}
开关（layoutManagerType）{
案例网格布局管理器：
mLayoutManager=新的GridLayoutManager（getActivity（），SPAN\u COUNT）；
mCurrentLayoutManagerType=LayoutManagerType.GRID\u LAYOUT\u MANAGER；
打破
案例线性布局管理器：
mLayoutManager=新的LinearLayoutManager（getActivity（））；
mCurrentLayoutManagerType=LayoutManagerType.LINEAR\u LAYOUT\u MANAGER；
打破
违约：
mLayoutManager=新的LinearLayoutManager（getActivity（））；
mCurrentLayoutManagerType=LayoutManagerType.LINEAR\u LAYOUT\u MANAGER；
}
mRecyclerView.setLayoutManager（mllayoutmanager）；
mRecyclerView.scrollToPosition（滚动位置）；
}
@凌驾
SaveInstanceState上的公共无效（Bundle savedInstanceState）{
savedInstanceState.putSerializable（键布局管理器，mCurrentLayoutManagerType）；
savedInstanceState.putParcelableArrayList（Constants.MY_DATA_SET_KEY，mDataset）；
super.onSaveInstanceState（savedInstanceState）；
}
@凌驾
public void setUserVisibleHint（布尔值isVisibleToUser）{
super.setUserVisibleHint（isVisibleToUser）；
if（isVisibleToUser&&mDataset.isEmpty（））{
Log.i（TAG_LIFE，“setUserVisibleHint”）；
新LoadRssFeedsItems（）.execute（Constants.HEALTH）；
}
this.isVisibleToUser=isVisibleToUser；
Log.i（TAG_LIFE，“setUserVisibleHint”+String.valueOf（this.isVisibleToUser））；
}   
私有枚举LayoutManagerType{
网格布局管理器，
线性布局管理器
}
公共类LoadRssFeedsItems扩展异步任务{
int i=0；
私有最终字符串未在\u Cutture=mySharedPreferences.loadStringPrefs（Constants.REMOVE\u KEY\u CULTURE\u catguty\u CATEGORY，“N/A”，MainActivity.context）；
private final String Not_interested_catguty_in_Since=mySharedPreferences.loadStringPrefs（Constants.REMOVE_KEY_sing_Since_CATEGORY，“N/A”，MainActivity.context）；
私有最终字符串未在\u Sport=mySharedPreferences.loadStringPrefs（Constants.REMOVE\u KEY\u Sport\u CATEGORY，“N/A”，MainActivity.context）中插入\u catguty\u；
私有最终字符串未在\u Socity=mySharedPreferences.loadStringPrefs（Constants.REMOVE\u KEY\u Socity\u CATEGORY，“N/A”，MainActivity.context）中插入\u catguty\u；
公共LoadrsFeedSitems（）{
}
受保护的字符串doInBackground（字符串…URL）{
试一试{
Document rssDocument=Jsoup.connect（URL[0]）.timeout（Constants.BIG_TIME_OUT）.ignoreContentType（true）.parser（parser.xmlParser（））.get（）；
Elements=rssDocument.select（Constants.ITEM）；
RssItem RssItem；
用于（图元：斜接）{
mTitle=element.select（“title”）.first（）.text（）；
mddescription=element.select（“description”）.first（）.text（）；
mLink=element.select（“链接”）.first（）.text（）；
mPubDate=element.select（“pubDate”）.first（）.text（）；
mCatgury=element.select（“category”）.first（）.text（）；
Log.i（标记，“项目标题：”+（mTitle==null？“不适用”：mTitle））；
Log.i（标记，“项目描述：”+（mDescription==null？“不适用”：mDescription））；
Log.i（标记，“项目链接：”+（mLink==null？“不适用”：mLink））；
Log.i（标记，“项目数据：”+（mPubDate==null？“不适用”：mPubDate））；
Log.i（标记，“项目图像链接：”+（mImageURL==null？“N/A”：mImageURL））；
Log.i（TAG，mCatgury）；
if（mCatgury.等于
{
继续；
}
rssItem=新的rssItem（mTitle、MDDescription、mPubDate、mLink、MCATGRY、i、getActi
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
          xmlns:app="http://schemas.android.com/apk/res-auto"
          android:layout_width="fill_parent"
          android:layout_height="match_parent"

          android:orientation="vertical">
<android.support.v7.widget.RecyclerView
    android:id="@+id/recycler_view"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:background="#fcffffff"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    />

<ProgressBar
    android:id="@+id/Progressbar"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:layout_marginTop="20dp"
    android:visibility="visible"
    ></ProgressBar>