Most visited

Recently visited

Results for

Summary: Inherited Constants | Ctors | Methods | Inherited Methods | [Expand All]

FragmentPagerAdapter

public abstract class FragmentPagerAdapter
extends PagerAdapter

java.lang.Object
	android.support.v4.view.PagerAdapter
		android.support.v13.app.FragmentPagerAdapter

实现 PagerAdapter ，表示每个页面为一个 Fragment ，只要用户可以返回页面，该页面将永久保存在片段管理器中。

这种版本的寻呼机最适合用于有少量通常需要寻呼的静态片段，比如一组选项卡。用户访问的每个页面的片段将保存在内存中，尽管其视图层次结构在不可见时可能会被破坏。这可能导致使用大量的内存，因为片段实例可以保持任意数量的状态。对于更大的页面集，请考虑FragmentStatePagerAdapter 。

当使用FragmentPagerAdapter时，主机ViewPager必须有一个有效的ID集。

子类只需要实现 getItem(int)和 getCount()以具有工作适配器。

以下是包含列表片段的寻呼机的示例实现：

public class FragmentPagerSupport extends Activity {
    static final int NUM_ITEMS = 10;

    MyAdapter mAdapter;

    ViewPager mPager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.fragment_pager);

        mAdapter = new MyAdapter(getFragmentManager());

        mPager = (ViewPager)findViewById(R.id.pager);
        mPager.setAdapter(mAdapter);

        // Watch for button clicks.
        Button button = (Button)findViewById(R.id.goto_first);
        button.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                mPager.setCurrentItem(0);
            }
        });
        button = (Button)findViewById(R.id.goto_last);
        button.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                mPager.setCurrentItem(NUM_ITEMS-1);
            }
        });
    }

    public static class MyAdapter extends FragmentPagerAdapter {
        public MyAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public int getCount() {
            return NUM_ITEMS;
        }

        @Override
        public Fragment getItem(int position) {
            return ArrayListFragment.newInstance(position);
        }
    }

    public static class ArrayListFragment extends ListFragment {
        int mNum;

        /**
         * Create a new instance of CountingFragment, providing "num"
         * as an argument.
         */
        static ArrayListFragment newInstance(int num) {
            ArrayListFragment f = new ArrayListFragment();

            // Supply num input as an argument.
            Bundle args = new Bundle();
            args.putInt("num", num);
            f.setArguments(args);

            return f;
        }

        /**
         * When creating, retrieve this instance's number from its arguments.
         */
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            mNum = getArguments() != null ? getArguments().getInt("num") : 1;
        }

        /**
         * The Fragment's UI is just a simple text view showing its
         * instance number.
         */
        @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);
            ((TextView)tv).setText("Fragment #" + mNum);
            return v;
        }

        @Override
        public void onActivityCreated(Bundle savedInstanceState) {
            super.onActivityCreated(savedInstanceState);
            setListAdapter(new ArrayAdapter<String>(getActivity(),
                    android.R.layout.simple_list_item_1, Cheeses.sCheeseStrings));
        }

        @Override
        public void onListItemClick(ListView l, View v, int position, long id) {
            Log.i("FragmentList", "Item clicked: " + id);
        }
    }
}

顶级片段的 R.layout.fragment_pager资源是：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical" android:padding="4dip"
        android:gravity="center_horizontal"
        android:layout_width="match_parent" android:layout_height="match_parent">

    <android.support.v4.view.ViewPager
            android:id="@+id/pager"
            android:layout_width="match_parent"
            android:layout_height="0px"
            android:layout_weight="1">
    </android.support.v4.view.ViewPager>

    <LinearLayout android:orientation="horizontal"
            android:gravity="center" android:measureWithLargestChild="true"
            android:layout_width="match_parent" android:layout_height="wrap_content"
            android:layout_weight="0">
        <Button android:id="@+id/goto_first"
            android:layout_width="wrap_content" android:layout_height="wrap_content"
            android:text="@string/first">
        </Button>
        <Button android:id="@+id/goto_last"
            android:layout_width="wrap_content" android:layout_height="wrap_content"
            android:text="@string/last">
        </Button>
    </LinearLayout>
</LinearLayout>

包含每个单独片段的布局的 R.layout.fragment_pager_list资源是：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:drawable/gallery_thumb">

    <TextView android:id="@+id/text"
        android:layout_width="match_parent" android:layout_height="wrap_content"
        android:gravity="center_vertical|center_horizontal"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="@string/hello_world"/>

    <!-- The frame layout is here since we will be showing either
    the empty view or the list view.  -->
    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="0dip"
        android:layout_weight="1" >
        <!-- Here is the list. Since we are using a ListActivity, we
             have to call it "@android:id/list" so ListActivity will
             find it -->
        <ListView android:id="@android:id/list"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:drawSelectorOnTop="false"/>

        <!-- Here is the view to show if the list is emtpy -->
        <TextView android:id="@android:id/empty"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="No items."/>

    </FrameLayout>

</LinearLayout>

摘要(Summary)

Inherited constants

From class android.support.v4.view.PagerAdapter

Public constructors
`FragmentPagerAdapter(FragmentManager fm)`

公共方法(Public methods)
`void`	`destroyItem(ViewGroup container, int position, Object object)` 删除给定位置的页面。
`void`	`finishUpdate(ViewGroup container)` 在所示页面中的更改完成时调用。
`abstract Fragment`	`getItem(int position)` 返回与指定位置关联的碎片。
`long`	`getItemId(int position)` 返回给定位置上项目的唯一标识符。
`Object`	`instantiateItem(ViewGroup container, int position)` 创建给定位置的页面。
`boolean`	`isViewFromObject(View view, Object object)` 确定页面视图是否与 `instantiateItem(ViewGroup, int)`返回的特定键对象相关联。
`void`	`restoreState(Parcelable state, ClassLoader loader)` 还原与此适配器及其先前由 `saveState()`保存的页面关联的任何实例状态。
`Parcelable`	`saveState()` 如果需要重建当前UI状态，请保存与此适配器及其应恢复的页面关联的任何实例状态。
`void`	`setPrimaryItem(ViewGroup container, int position, Object object)` 被调用以通知适配器当前哪个项目被认为是“主要”，这是向用户显示的当前页面。
`void`	`startUpdate(ViewGroup container)` 当所显示页面的变化即将开始时调用。

继承方法(Inherited methods)

From class android.support.v4.view.PagerAdapter

From class java.lang.Object

Public constructors