如何使用 FragmentPagerAdapter 来拥有不同内容的选项卡? [英] How do I use FragmentPagerAdapter to have tabs with different content?
本文介绍了如何使用 FragmentPagerAdapter 来拥有不同内容的选项卡?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想要不同的标签，你可以像在安卓市场那样滑动.每个选项卡应使用一个片段并为其使用一种方法.
I want to have different tabs, where you can swipe through like in the android market. Each tab should use one fragment and use one method for it.
这是我的 FragmentPagerAdapter 类:
This is my FragmentPagerAdapter class:
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
Fragment fragment =null;
switch (position) {
case 0:
fragment = new ConnectionFragment();
break;
case 1:
fragment = new DataFragment();
break;
case 2:
fragment = new GraphFragment();
break; }
return fragment;
}
@Override
public int getCount() {
// Show 3 total pages.
return 3;
}
}
对于每个片段类型/标签，我有三个类:
And I have three classes for each fragment type/tab:
public static class ConnectionFragment extends Fragment {
public static final String ARG_SECTION_NUMBER = "section_number";
public String stringConnectionStatus = "Offline";
public String stringWiflyIp = "0.0.0.0";
public ConnectionFragment() {}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View connectionView = inflater.inflate(R.layout.fragment_connection,
container, false);
TextView statusView = (TextView) connectionView.findViewById(R.id.status_label);
statusView.setText("Connection status: " + stringConnectionStatus);
TextView ipView = (TextView) connectionView.findViewById(R.id.ip_label);
ipView.setText("WiFly IP: " + stringWiflyIp);
/**TextView sectionBarView = (TextView) connectionView
.findViewById(R.id.section_label);
sectionBarView.setText("pups");"*/
return connectionView;
}
}
public static class DataFragment extends Fragment {
public DataFragment() {}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View dataView = inflater.inflate(R.layout.fragment_data,
container, false);
TextView sectionBarView = (TextView) dataView
.findViewById(R.id.section_label);
sectionBarView.setText("pups2");
return dataView;
}
}
public static class GraphFragment extends Fragment {
public GraphFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_graph,
container, false);
TextView sectionBarView = (TextView) rootView
.findViewById(R.id.section_label);
sectionBarView.setText("pups3");
return rootView;
}
}
每个片段都应该是可定制的，这就是为什么我有三个类.
Each Fragment should be customizable, thats why I have three classes.
尽管如此，应用程序还是在 getItem 方法中崩溃了.有任何想法吗?谢谢！
Nevertheless, the app crashes in the getItem method. Any ideas? Thank you!
完整的 MainActivity.java:
The complete MainActivity.java:
import ...
public class MainActivity extends FragmentActivity {
/**
* The {@link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {@link android.support.v4.app.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;
public List<String> fragments = new Vector<String>();
/**
* 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);
// Create the adapter that will return a fragment for each of the three
// primary sections of the app.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager); //pager
mViewPager.setAdapter(mSectionsPagerAdapter);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
/**
* 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);
fragments.add(ConnectionFragment.class.getName());
fragments.add(DataFragment.class.getName());
fragments.add(GraphFragment.class.getName());
//fragmentsA = "fragments";
}
@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
/*Fragment fragment =null;
switch (position) {
case 0:
fragment = new ConnectionFragment();
break;
case 1:
fragment = new DataFragment();
break;
case 2:
fragment = new GraphFragment();
break; }
return fragment;*/
return Fragment.instantiate(getBaseContext(), fragments.get(position));
}
@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_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
/**
* A dummy fragment representing a section of the app, but that simply
* displays dummy text.
*/
public static class ConnectionFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public String stringConnectionStatus = "Offline";
public String stringWiflyIp = "0.0.0.0";
public ConnectionFragment() {}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View connectionView = inflater.inflate(R.layout.fragment_connection,container, false);
TextView statusView = (TextView) connectionView.findViewById(R.id.status_label);
statusView.setText("Connection status: " + stringConnectionStatus);
TextView ipView = (TextView) connectionView.findViewById(R.id.ip_label);
ipView.setText("WiFly IP: " + stringWiflyIp);
/**TextView sectionBarView = (TextView) connectionView
.findViewById(R.id.section_label);
sectionBarView.setText("pups");"*/
return connectionView;
}
}
public static class DataFragment extends Fragment {
public DataFragment() {}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View dataView = inflater.inflate(R.layout.fragment_data,
container, false);
//TextView sectionBarView = (TextView) dataView.findViewById(R.id.section_label);
//sectionBarView.setText("pups2");
return dataView;
}
}
public static class GraphFragment extends Fragment {
public GraphFragment() {}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_graph,
container, false);
//TextView sectionBarView = (TextView) rootView.findViewById(R.id.section_label);
//sectionBarView.setText("pups3");
return rootView;
}
}
}
推荐答案
创建适配器:
class MyPagerAdapter extends FragmentPagerAdapter {
public List<String> fragmentsA;
public MyPagerAdapter(FragmentManager fm) {
super(fm);
fragmentsA = fragments;
}
@Override
public Fragment getItem(int position) {
//return MyFragment.newInstance();
return Fragment.instantiate(context, fragmentsA.get(position));
}
@Override
public CharSequence getPageTitle(int position) {
//return CONTENT[position % CONTENT.length].toUpperCase();
return mEntries.get(position % CONTENT.length).toUpperCase();
}
@Override
public int getCount() {
// return CONTENT.length;
return mEntries.size();
}
@Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
}
每个片段属于不同的类.
Each fragment belongs to different classes.
所以你必须定义一个片段列表(这些去主 FragmentActivity):
So you have to define a fragment list (These go to the main FragmentActivity) :
static MyPagerAdapter adapter;
并用片段填充它:
fragments.add(ConnectionFragment.class.getName());
fragments.add(DataFragment.class.getName());
fragments.add(Tab3.class.getName());
//..etc
然后你必须像这样将片段添加到适配器中:
Then you have to add the fragments to the adapter like this:
pager = (ViewPager)findViewById(R.id.viewpager);
adapter = new MyPagerAdapter(getSupportFragmentManager());
pager.setAdapter(adapter);
MyPagerAdaper 将遍历 fragments 列表中包含的所有片段，然后实例化每个片段.
The MyPagerAdaper will go through all the fragments contained by the fragments list, then it will instantiate each of them.
这篇关于如何使用 FragmentPagerAdapter 来拥有不同内容的选项卡?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
