我正在尝试使用PagerSlidingTabStrip库以新的方式实现ViewPager。我认为代码很好，但是当我尝试将适配器设置为ViewPager时，我遇到了错误。在我开始使用PagerSlidingTabStrip之前，我的代码工作正常，但该代码现已弃用。
错误：
java.lang.RuntimeException: Unable to start activity
ComponentInfo{com.adrissa.klea/com.adrissa.klea.MainActivity}:
java.lang.NullPointerException Caused by:
java.lang.NullPointerException at
com.adrissa.klea.MainActivity.onInt(MainActivity.java:103) at
br.liveo.navigationliveo.NavigationLiveo.mountListNavigation(NavigationLiveo.java:248)
at
br.liveo.navigationliveo.NavigationLiveo.onCreate(NavigationLiveo.java:104)
at android.app.Activity.performCreate(Activity.java:5451)
这是ViewPager的实现：
public class MainActivity extends NavigationLiveo implements
br.liveo.interfaces.OnItemClickListener, NavigationDrawerFragment.NavigationDrawerCallbacks,
ActionBar.TabListener {
/**
* Fragment managing the behaviors, interactions and presentation of the
* navigation drawer.
*/
private HelpLiveo mLiveo;
ViewPager mViewPager;
FragmentPagerAdapter mSectionsPagerAdapter;
String category;
public static ArrayList<String> categoriesForSellClass = new ArrayList<String>();
/**
* Used to store the last screen title. For use in
* {@link #restoreActionBar()}.
*/
private CharSequence mTitle;
@Override
public void onInt(Bundle savedInstanceState) {
//super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//user information NavDrawer
this.userName.setText("Name");
this.userEmail.setText("Email");
this.userPhoto.setImageResource(R.drawable.selfie);
this.userBackground.setImageResource(R.drawable.nav_drawer_bg);
//setup navigation drawer
mLiveo = new HelpLiveo();
mLiveo.add(getString(R.string.home), R.drawable.home);
mLiveo.add(getString(R.string.my_adverts), R.drawable.price);
mLiveo.add(getString(R.string.messages), R.drawable.envelope);
mLiveo.addSeparator();
mLiveo.add(getString(R.string.settings), R.drawable.settings);
mLiveo.add(getString(R.string.log_out), R.drawable.power);
with(this, Navigation.THEME_LIGHT).startingPosition(0)
.addAllHelpItem(mLiveo.getHelp())
.setOnClickUser(onClickPhoto)
.setOnPrepareOptionsMenu(onPrepare)
.build();
mTitle = getTitle();
mSectionsPagerAdapter = new MyPagerAdapter(
getSupportFragmentManager());
final ActionBar actionBar = getSupportActionBar();
//actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
//here is line 103 \/
mViewPager.setAdapter(mSectionsPagerAdapter);
PagerSlidingTabStrip tabs = (PagerSlidingTabStrip) findViewById(R.id.tabs);
tabs.setViewPager(mViewPager);
// 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.
tabs
.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
mViewPager.requestTransparentRegion(mViewPager);
ParseQuery<ParseObject> query = ParseQuery.getQuery("Categories");
query.findInBackground(new FindCallback<ParseObject>() {
@SuppressLint("NewApi")
public void done(List<ParseObject> objects, ParseException e) {
if (e == null) {
categoriesForSellClass.add("Alle");
categoriesForSellClass.add("Favoritter");
for (int i = 0; i < objects.size(); i++) {
ParseObject pObject = objects.get(i);
category = pObject.getString("name");
categoriesForSellClass.add(category);
}
// onSucced(objects);
} else {
}
}
});
}
@Override
public void onNavigationDrawerItemSelected(int position) {
// update the main content by replacing fragments
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.container, AllFragment.newInstance(position + 1))
.commit();
}
private View.OnClickListener onClickPhoto = new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "onClickPhoto :D", Toast.LENGTH_SHORT).show();
closeDrawer();
}
};
private OnPrepareOptionsMenuLiveo onPrepare = new OnPrepareOptionsMenuLiveo() {
@Override
public void onPrepareOptionsMenu(Menu menu, int position, boolean visible) {
}
};
public void onSectionAttached(int number) {
switch (number) {
case 1:
mTitle = getString(R.string.title_section1);
break;
case 2:
mTitle = getString(R.string.title_section2);
break;
case 3:
mTitle = getString(R.string.title_section3);
break;
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public void onItemClick(int position) {
Fragment mFragment;
FragmentManager mFragmentManager = getSupportFragmentManager();
mFragment = null;
switch (position){
case 2:
//mFragment = new ViewPagerFragment();
break;
default:
//mFragment = MainFragment.newInstance(mHelpLiveo.get(position).getName());
break;
}
if (mFragment != null){
mFragmentManager.beginTransaction().replace(R.id.container, mFragment).commit();
}
}
PagerAdapter类：
public class MyPagerAdapter extends FragmentPagerAdapter implements PagerSlidingTabStrip.IconTabProvider{
public MyPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public int getCount() {
// Show 5 total pages.
return 5;
}
final int[] ICONS = new int[] {
R.drawable.ic_action_camera,
R.drawable.ic_action_person,
R.drawable.ic_action_important,
R.drawable.ic_action_time,
R.drawable.ic_action_map
};
@Override
public Fragment getItem(int i) {
switch (i) {
case 0:
return new AllFragment();
case 1:
return new ProfileFragment();
case 2:
return new ThirdFragment();
case 3:
return new ProfileFragment();
case 4:
return new MapFragment().newInstance(new LatLng(55.7200,
10.5700));
}
return null;
}
@Override
public int getPageIconResId(int i) {
return ICONS[i];
}
}
main_activity.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.astuetz.PagerSlidingTabStrip
android:id="@+id/tabs"
android:layout_width="match_parent"
android:layout_height="48dip" />
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#f3f6f7"></android.support.v4.view.ViewPager>
</RelativeLayout>
感谢任何帮助！
答案 0 :(得分：0)
看起来您已将onCreate（Bundle args）的名称更改为onInt（）：
@Override
public void onInt(Bundle savedInstanceState) {
//super.onCreate(savedInstanceState);
将方法名称更改回onCreate（）。