Android中ViewPager和Fragment的使用

时间:2021-05-20

小案例

XML中

<android.support.v4.view.ViewPager android:id="@+id/viewPager" android:layout_width="match_parent" android:layout_height="match_parent"></android.support.v4.view.ViewPager>

创建Fragment

fragments = new ArrayList<>(); ConversationFragment fragment1 = new ConversationFragment(); GroupFragment fragment2 = new GroupFragment(); SearchFragment fragment3 = new SearchFragment(); fragments.add(fragment1); fragments.add(fragment2); fragments.add(fragment3); adapter = new MainPagerAdapter(getSupportFragmentManager(), fragments); viewPager.setAdapter(adapter);

adapter

public class MainPagerAdapter extends FragmentPagerAdapter{ List<Fragment> fragmentList; public MainPagerAdapter(FragmentManager fm, List<Fragment> fragmentList) { super(fm); this.fragmentList = fragmentList; } @Override public Fragment getItem(int position) { return fragmentList.get(position); } @Override public int getCount() { return fragmentList.size(); }}

OnPageChangeListener

viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() { @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { int distance = positionOffsetPixels / 3; //一旦fragment滑动,这里的position实际是前一个的 ViewPropertyAnimator.animate(v_indicate_line).translationX(distance + position * v_indicate_line.getWidth()).setDuration(0); } @Override public void onPageSelected(int position) { textLightAndSize(); } @Override public void onPageScrollStateChanged(int state) { }});

配合其他点击事件

//这里是注意setCurrentItem的用法switch (view.getId()) { case R.id.ly_conversation: viewPager.setCurrentItem(0); break; case R.id.ly_group: viewPager.setCurrentItem(1); break; case R.id.ly_search: viewPager.setCurrentItem(2); break;}

官方案例

R.layout.fragment_pager

<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>

R.layout.fragment_pager_list

<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>public class FragmentPagerSupport extends FragmentActivity { 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(getSupportFragmentManager()); 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); } }}

注意

3.0之前的Activity是不能用fragment的。为了能使用fragment(supportV4中),才有了FragmentActivity。FragmentActivity继承的Activity。

以上就是本文的全部内容,希望对大家学习Android软件编程有所帮助。

声明:本页内容来源网络,仅供用户参考;我单位不保证亦不表示资料全面及准确无误,也不保证亦不表示这些资料为最新信息,如因任何原因,本网内容或者用户因倚赖本网内容造成任何损失或损害,我单位将不会负任何法律责任。如涉及版权问题,请提交至online#300.cn邮箱联系删除。

相关文章