Android：Fragment和ViewPager始终在第一个位置启动_app

概述我在Android应用程序中使用Master/Detail设计.如果我单击ItemListActivity中列表视图中的项目,则会将位置提供给我的ItemDetailActivity.这个实现了ViewPager和FragmentStatePagerAdapter.所以我想在细节视图之间滑动.我不知道如何告诉ViewPager从所需的位置开始(ItemListActivi

我在Android应用程序中使用Master / Detail设计.如果我单击ItemListActivity中列表视图中的项目,则会将位置提供给我的ItemDetailActivity.这个实现了VIEwPager和FragmentStatePagerAdapter.所以我想在细节视图之间滑动.

我不知道如何告诉VIEwPager从所需的位置开始(ItemListActivity中的整数).无论我在列表中点击哪一个,我的VIEwPager始终位于列表的第0位.

这是我的代码：

ItemDetailActivity

public class ItemDetailActivity extends FragmentActivity {    RSSFeed Feed;    int pos;    private static List<Fragment> fragments;    /**     * The pager Widget, which handles animation and allows swiPing horizontally to access prevIoUs     * and next wizard steps.     */    private VIEwPager mPager;    /**     * The pager adapter, which provIDes the pages to the vIEw pager Widget.     */    private PagerAdapter mPagerAdapter;    @OverrIDe    protected voID onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        // define layout of this activity        setContentVIEw(R.layout.activity_item_detail);        // Get the Feed object and the position from the Intent        Feed = (RSSFeed) getIntent().getExtras().get("Feed");        //position of the clicked item from the List        pos = getIntent().getExtras().getInt("pos");        //create all 20 ItemDetailFragments        fragments = new ArrayList<Fragment>();         for(int i=0; i<=20; i++)                fragments.add(ItemDetailFragment.create(i ,Feed));        // Instantiate a VIEwPager and a PagerAdapter.        mPager = (VIEwPager) findVIEwByID(R.ID.vIEwpager);        mPagerAdapter = new ScreenSlIDePagerAdapter(getSupportFragmentManager());        mPager.setAdapter(mPagerAdapter);        mPager.setPagetransformer(true, new ZoomOutPagetransformer());    }    @OverrIDe    public voID onBackpressed() {        if (mPager.getCurrentItem() == 0) {            // If the user is currently looking at the first step, allow the system to handle the            // Back button. This calls finish() on this activity and pops the back stack.            super.onBackpressed();        } else {            // Otherwise, select the prevIoUs step.            mPager.setCurrentItem(mPager.getCurrentItem() - 1);        }    }    /**     * A simple pager adapter that represents ItemDetailFragment objects, in     * sequence.     *      * Creates a class that extends the FragmentStatePagerAdapter abstract class and     * implements the getItem() method to supply instances of ScreenSlIDePageFragment     * as new pages. The pager adapter also requires that you implement the getCount()     * method, which returns the amount of pages the adapter will create.      */    private class ScreenSlIDePagerAdapter extends FragmentStatePagerAdapter {        public ScreenSlIDePagerAdapter(FragmentManager fm) {            super(fm);        }        @OverrIDe        public Fragment getItem(int page_number) {            return fragments.get(page_number);        }        @OverrIDe        public int getCount() {            //get the count of items in the Feed            return Feed.getItemCount();        }    }

ItemDetailFragment：

/** * A fragment representing a single Item detail screen. This fragment is either * contained in a {@link ItemListActivity} in two-pane mode (on tablets) or a * {@link ItemDetailActivity} on handsets. */public class ItemDetailFragment extends Fragment {    private static int fPos;    static RSSFeed fFeed;    private ShareActionProvIDer mShareActionProvIDer;    Date pDate;    /**     * Mandatory empty constructor for the fragment manager to instantiate the     * fragment (e.g. upon screen orIEntation changes).     */    public ItemDetailFragment() {    }    /**     * Factory method for this fragment class. Constructs a new fragment for the given page number.     */    public static ItemDetailFragment create(int pos, RSSFeed Feed) {        ItemDetailFragment fragment = new ItemDetailFragment();             Bundle args = new Bundle();        args.putSerializable("Feed", Feed);        args.putInt("pos", pos);        fragment.setArguments(args);                return fragment;    }    @OverrIDe    public voID onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        // show Actionbar        setHasOptionsMenu(true);        // get data from DetailActivity        fFeed = (RSSFeed) getArguments().getSerializable("Feed");        fPos = getArguments().getInt("pos");    }    @OverrIDe    public VIEw onCreateVIEw(LayoutInflater inflater, VIEwGroup container,            Bundle savedInstanceState) {        // inflate the fragment with the custom detail fragment        VIEw vIEw = inflater                .inflate(R.layout.detail_fragment, container, false);        return vIEw;    }@Suppresslint("SetJavaScriptEnabled")    @OverrIDe    public voID onActivityCreated(Bundle savedInstanceState) {        super.onActivityCreated(savedInstanceState);               //here I put the data in my webvIEw    }

activity_item_detail.xml

<relativeLayout xmlns:androID="http://schemas.androID.com/apk/res/androID"    xmlns:tools="http://schemas.androID.com/tools"    xmlns:app="http://schemas.androID.com/apk/lib/com.Google.ads"    androID:ID="@+ID/main_item_layout"    androID:layout_wIDth="match_parent"    androID:layout_height="match_parent" >   <androID.support.v4.vIEw.VIEwPager     androID:ID="@+ID/vIEwpager"     androID:layout_wIDth="fill_parent"     androID:layout_height="fill_parent" />    <FrameLayout        androID:ID="@+ID/item_detail_container"        androID:layout_wIDth="match_parent"        androID:layout_height="match_parent"        androID:layout_above="@+ID/adVIEw"        androID:layout_alignParentleft="true"        androID:layout_alignParenttop="true"        tools:context=".ItemDetailActivity"        tools:ignore="MergeRootFrame" >    </FrameLayout>

所以目前我可以对所有项目进行平局,但始终从第一项开始.我想在我列表视图中点击的那个项目上启动它.

我怎样才能做到这一点？

解决方法:

根据文档,您需要做的就是使用