我正在创建一个应用程序并偶然发现了一个问题。我的应用程序片段应在选择时显示文本，但事实并非如此。这是我的代码：
这个类是我的片段，它应该在选择时显示文本。
TestFragment.class：
public class TestFragment extends SherlockFragment {
public static final String EXTRA_TITLE = "title";
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
TextView txt = new TextView(inflater.getContext());
txt.setGravity(Gravity.CENTER);
txt.setText("Fragment");
if (getArguments() != null && getArguments().containsKey(EXTRA_TITLE)) {
txt.setText(getArguments().getString(EXTRA_TITLE));
}
return txt;
}
public static Bundle createBundle(String title) {
Bundle bundle = new Bundle();
bundle.putString(EXTRA_TITLE, title);
return bundle;
}
}
这是我的主要课程，从我的标签中添加。它扩展了我之前制作的 TabSwipeActivity。主类：
public class TaskMain extends TabSwipeActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addTab("Urgent", TestFragment.class,
TestFragment.createBundle("TestFragment"));
addTab("Due", TestFragment.class,
TestFragment.createBundle("Fragment 2"));
addTab("Unimportant", TestFragment.class,
TestFragment.createBundle("Fragment 3"));
addTab("Shopping", TestFragment.class,
TestFragment.createBundle("Fragment 4"));
addTab("Notes", TestFragment.class,
TestFragment.createBundle("Fragment 5"));
}
@Override
public boolean onCreateOptionsMenu(com.actionbarsherlock.view.Menu menu) {
super.onCreateOptionsMenu(menu);
MenuInflater inflate = getSupportMenuInflater();
inflate.inflate(R.menu.activity_task_main, menu);
return true;
}
}
这是我的主要活动扩展的 TabSwipeActivity。TabSwipeActivity.class：
public abstract class TabSwipeActivity extends SherlockFragmentActivity {
private ViewPager mViewPager;
private TabsAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
/*
* Create the ViewPager and our custom adapter
*/
mViewPager = new ViewPager(this);
adapter = new TabsAdapter(this, mViewPager);
mViewPager.setAdapter(adapter);
mViewPager.setOnPageChangeListener(adapter);
/*
* We need to provide an ID for the ViewPager, otherwise we will get an
* exception like:
*
* java.lang.IllegalArgumentException: No view found for id 0xffffffff
* for fragment TestFragment{40de5b90 #0 id=0xffffffff
* android:switcher:-1:0} at
* android.support.v4.app.FragmentManagerImpl.moveToState
* (FragmentManager.java:864)
*
* The ID 0x7F04FFF0 is large enough to probably never be used for
* anything else
*/
mViewPager.setId(0x7F04FFF0);
super.onCreate(savedInstanceState);
/*
* Set the ViewPager as the content view
*/
setContentView(mViewPager);
}
/**
* Add a tab with a backing Fragment to the action bar
*
* @param titleRes
* A string resource pointing to the title for the tab
* @param fragmentClass
* The class of the Fragment to instantiate for this tab
* @param args
* An optional Bundle to pass along to the Fragment (may be null)
*/
protected void addTab(int titleRes,
Class<? extends SherlockFragment> fragmentClass, Bundle args) {
adapter.addTab(getString(titleRes), fragmentClass, args);
}
/**
* Add a tab with a backing Fragment to the action bar
*
* @param titleRes
* A string to be used as the title for the tab
* @param fragmentClass
* The class of the Fragment to instantiate for this tab
* @param args
* An optional Bundle to pass along to the Fragment (may be null)
*/
protected void addTab(CharSequence title,
Class<? extends SherlockFragment> fragmentClass, Bundle args) {
adapter.addTab(title, fragmentClass, args);
}
private void setContent() {
setContentView(R.layout.activity_task_new);
}
private static class TabsAdapter extends FragmentPagerAdapter implements
TabListener, ViewPager.OnPageChangeListener {
private final SherlockFragmentActivity mActivity;
private final ActionBar mActionBar;
private final ViewPager mPager;
/**
* @param fm
* @param fragments
*/
public TabsAdapter(SherlockFragmentActivity activity, ViewPager pager) {
super(activity.getSupportFragmentManager());
this.mActivity = activity;
this.mActionBar = activity.getSupportActionBar();
this.mPager = pager;
mActionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
}
private static class TabInfo {
public final Class<? extends SherlockFragment> fragmentClass;
public final Bundle args;
public TabInfo(Class<? extends SherlockFragment> fragmentClass,
Bundle args) {
this.fragmentClass = fragmentClass;
this.args = args;
}
}
private List<TabInfo> mTabs = new ArrayList<TabInfo>();
public void addTab(CharSequence title,
Class<? extends SherlockFragment> fragmentClass, Bundle args) {
final TabInfo tabInfo = new TabInfo(fragmentClass, args);
Tab tab = mActionBar.newTab();
tab.setText(title);
tab.setTabListener(this);
tab.setTag(tabInfo);
mTabs.add(tabInfo);
mActionBar.addTab(tab);
notifyDataSetChanged();
}
@Override
public SherlockFragment getItem(int position) {
final TabInfo tabInfo = mTabs.get(position);
return (SherlockFragment) SherlockFragment.instantiate(mActivity,
tabInfo.fragmentClass.getName(), tabInfo.args);
}
@Override
public int getCount() {
return mTabs.size();
}
public void onPageScrollStateChanged(int arg0) {
}
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
public void onPageSelected(int position) {
/*
* Select tab when user swiped
*/
mActionBar.setSelectedNavigationItem(position);
}
public void onTabSelected(Tab tab, FragmentTransaction ft) {
/*
* Slide to selected fragment when user selected tab
*/
TabInfo tabInfo = (TabInfo) tab.getTag();
for (int i = 0; i < mTabs.size(); i++) {
if (mTabs.get(i) == tabInfo) {
mPager.setCurrentItem(i);
}
}
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
}
}