Android ViewPager仅显示最后一个片段
我正在Android Studio中基于向导设置选项卡式ViewPager布局。 我创建了两个片段用于ViewPager,以及包含的占位符 仅显示最后一个片段,以其上的哪个选项卡为准 MainActivity.java:Android ViewPager仅显示最后一个片段,android,android-fragments,android-viewpager,Android,Android Fragments,Android Viewpager,我正在Android Studio中基于向导设置选项卡式ViewPager布局。 我创建了两个片段用于ViewPager,以及包含的占位符 仅显示最后一个片段,以其上的哪个选项卡为准 MainActivity.java: public class MainActivity extends ActionBarActivity implements ActionBar.TabListener, TunerFragment.OnFragmentInteractionListener, Settings
public class MainActivity extends ActionBarActivity implements ActionBar.TabListener, TunerFragment.OnFragmentInteractionListener, SettingsFragment.OnFragmentInteractionListener {
/**
* The {@link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {@link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive, it
* may be best to switch to a
* {@link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {@link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Set up the action bar.
final ActionBar actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
actionBar.setDisplayShowTitleEnabled(false);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
mViewPager.setCurrentItem(1);
// When swiping between different sections, select the corresponding
// tab. We can also use ActionBar.Tab#select() to do this if we have
// a reference to the Tab.
mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(
actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
Log.v("tab selected", tab.getPosition() + ":" + tab.toString() +" - "+fragmentTransaction.toString());
mViewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
@Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
@Override
public void onFragmentInteraction(Uri uri) {
Log.v("onFragmentInteraction",uri.toString());
}
@Override
public void onFragmentInteraction(String id) {
Log.v("onFragmentInteraction",id);
}
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
Fragment fragment = new Fragment();
Log.v("MainActivity","position:"+ position);
switch (position) {
case 0:
fragment = new TunerFragment();
case 1:
fragment = PlaceholderFragment.newInstance(position + 1);
case 2:
fragment = new SettingsFragment();
default:
break;
}
return fragment;
}
@Override
public int getCount() {
// Show 3 total pages.
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_tuner).toUpperCase(l);
case 1:
return getString(R.string.title_scale).toUpperCase(l);
case 2:
return getString(R.string.title_settings).toUpperCase(l);
}
return null;
}
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}
公共类MainActivity扩展ActionBarActivity实现ActionBar.TableListener、TunerFragment.OnFragmentInteractionListener、SettingsFragment.OnFragmentInteractionListener{
/**
*将提供的{@link android.support.v4.view.PagerAdapter}
*每个部分的片段。我们使用
*{@link FragmentPagerAdapter}派生,它将保留
*已在内存中加载片段。如果这变得过于内存密集,则
*最好是换成一个
*{@link android.support.v4.app.FragmentStatePagerAdapter}。
*/
分段SPAGERADAPTER mSectionsPagerAdapter;
/**
*将承载节内容的{@link ViewPager}。
*/
ViewPager mViewPager;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//设置操作栏。
最终ActionBar ActionBar=getSupportActionBar();
actionBar.setNavigationMode(actionBar.NAVIGATION\u MODE\u选项卡);
actionBar.setDisplayShowTitleEnabled(false);
//创建适配器,该适配器将为这三个函数中的每一个返回一个片段
//活动的主要部分。
mSectionsPagerAdapter=newsectionspageradapter(getSupportFragmentManager());
//使用分区适配器设置ViewPager。
mViewPager=(ViewPager)findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
mViewPager.setCurrentItem(1);
//在不同区段之间滑动时,选择相应的
//我们也可以使用ActionBar.tab#select()来完成这项工作
//对选项卡的引用。
mViewPager.setOnPageChangeListener(新的ViewPager.SimpleOnPageChangeListener(){
@凌驾
已选择页面上的公共无效(内部位置){
actionBar.setSelectedNavigationItem(位置);
}
});
//对于应用程序中的每个部分,在操作栏中添加一个选项卡。
对于(int i=0;i@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
Fragment fragment = new Fragment();
Log.v("MainActivity","position:"+ position);
switch (position) {
case 0:
fragment = new TunerFragment();
// should insert break;
case 1:
fragment = PlaceholderFragment.newInstance(position + 1);
// should insert break;
case 2:
fragment = new SettingsFragment();
default:
break;
}
return fragment;
}