【发布时间】：2015-12-03 17:38:49
【问题描述】：
我有这个活动：
我在 Android Studio 1.5 中使用 New Activity->Tabbed Activity 创建了它
他们为我提供了以下在您创建此类活动时生成的代码：
public class Main2Activity extends AppCompatActivity {
/**
* 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}.
*/
private SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {@link ViewPager} that will host the section contents.
*/
private ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// 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.container);
mViewPager.setAdapter(mSectionsPagerAdapter);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(mViewPager);
//--------------------------------------------------------------------
//Here is the custom code
View view = getLayoutInflater().inflate(R.layout.custom_tab,null);
view.findViewById(R.id.custom_tab_imageView).setBackgroundResource(R.mipmap.ic_launcher);
TabLayout.Tab tab = tabLayout.newTab().setCustomView(view);
tabLayout.addTab(tab);
//----------------------------------------------------------------------
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
@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_main2, 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);
}
/**
* 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";
public PlaceholderFragment() {
}
/**
* 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;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main2, container, false);
TextView textView = (TextView) rootView.findViewById(R.id.section_label);
textView.setText(getString(R.string.section_format, getArguments().getInt(ARG_SECTION_NUMBER)));
return rootView;
}
}
/**
* 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).
return PlaceholderFragment.newInstance(position + 1);
}
@Override
public int getCount() {
// Show 3 total pages.
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "SECTION 1";
case 1:
return "SECTION 2";
case 2:
return "SECTION 3";
}
return null;
}
}
我想在三个现有选项卡之外添加一个新的自定义选项卡，因此我创建了 custom_tab.xml，其中包含一个 id=custom_tab_imageView 的 ImageView，并将以下内容添加到 onCreate()：
View view = getLayoutInflater().inflate(R.layout.custom_tab,null);
view.findViewById(R.id.custom_tab_imageView).setBackgroundResource(R.mipmap.ic_launcher);
TabLayout.Tab tab = tabLayout.newTab().setCustomView(view);
tabLayout.addTab(tab);
在 SECTION 1,2,3 中显示了一个 PlaceholderFragment，上面写着“Hello World from section...”
如何修改 SectionsPagerAdapter 以便在用户点击自定义选项卡时显示“第 4 节的 Hello world”？ 或者如何让适配器将其识别为第四个选项卡？
【问题讨论】：
-
修改你的
SectionsPagerAdapter's`getCount`方法为return4. -
@Trivial 我已经这样做了，但它只在 SECTION 3 和我的自定义选项卡之间添加了一个空选项卡。
-
添加标签后尝试设置适配器。我认为它会起作用。
-
@Trivial 我知道每种方法，也了解它的作用，但我不知道如何正确设置适配器。您能帮我提供一些代码或示例吗？
-
我确定这就是你要找的。span>
标签： android android-fragments android-tabs