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我创建了滑动选项卡并添加了一种方法来删除某个位置的给定选项卡。如果我尝试删除除当前选项卡以外的任何选项卡，它工作正常。在这种情况下，代码会抛出 IllegalStateException。请让我知道我的错误是什么。

以下是我的代码：

public class TabsAdapter extends FragmentPagerAdapter implements ActionBar.TabListener, ViewPager.OnPageChangeListener {
private final Context mContext;
private final ActionBar mActionBar;
private final ViewPager mViewPager;
private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();
private final String TAG = "TABS_ADAPTER";

final class TabInfo {
    private final Class<?> clss;
    private final Bundle args;

    TabInfo(Class<?> _class, Bundle _args) {
        clss = _class;
        args = _args;
    }
}

public TabsAdapter(FragmentActivity activity, ViewPager pager) {
    super(activity.getSupportFragmentManager());
    mContext = activity;
    mActionBar = activity.getActionBar();
    mViewPager = pager;
    mViewPager.setAdapter(this);
    mViewPager.setOnPageChangeListener(this);
}

public void addTab(ActionBar.Tab tab, Class<?> clss, Bundle args) {
    TabInfo info = new TabInfo(clss, args);
    tab.setTag(info);
    tab.setTabListener(this);
    mTabs.add(info);
    mActionBar.addTab(tab);
    notifyDataSetChanged();
}


public int getCount() {
    return mTabs.size();
}

public Fragment getItem(int position) {
    TabInfo info = mTabs.get(position);
    return Fragment.instantiate(mContext, info.clss.getName(), info.args);
}


public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}


public void onPageSelected(int position) {
    mActionBar.setSelectedNavigationItem(position);
}


public void onPageScrollStateChanged(int state) {
}


public void onTabSelected(Tab tab, FragmentTransaction ft) {
    mViewPager.setCurrentItem(tab.getPosition());
    Log.v(TAG, "clicked");
    Object tag = tab.getTag();
    for (int i=0; i<mTabs.size(); i++) {
        if (mTabs.get(i) == tag) {
            mViewPager.setCurrentItem(i);
        }
    }
}

public void onTabUnselected(Tab tab, FragmentTransaction ft) {}

public void onTabReselected(Tab tab, FragmentTransaction ft) {}

public void onTabReselected(Tab tab, android.app.FragmentTransaction ft) {}

@Override
public void onTabSelected(Tab tab, android.app.FragmentTransaction ft) {    
    Object tag = tab.getTag();
    for (int i=0; i<mTabs.size(); i++) {
        if (mTabs.get(i) == tag) {
            mViewPager.setCurrentItem(i);
        }
    }       
}

public void onTabUnselected(Tab tab, android.app.FragmentTransaction ft) {}

public void removeTab(ActionBar.Tab tab) {
    mTabs.remove(tab.getTag());
    mActionBar.removeTab(tab);
    //mTabs.remove(mViewPager.getCurrentItem());
    //mActionBar.removeTabAt(mViewPager.getCurrentItem());
    notifyDataSetChanged();
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    // TODO Auto-generated method stub
    super.destroyItem(container, position, object);
    FragmentManager manager = ((Fragment) object).getFragmentManager();
    FragmentTransaction trans = manager.beginTransaction();
    trans.remove((Fragment) object);
    trans.commit();
}
}

以下是 logcat 错误：

   06-26 15:57:00.149: E/AndroidRuntime(17064): FATAL EXCEPTION: main
   06-26 15:57:00.149: E/AndroidRuntime(17064): java.lang.IllegalStateException: The application's PagerAdapter changed the adapter's contents without calling  PagerAdapter#notifyDataSetChanged! Expected adapter item count: 3, found: 2 Pager id: com.sparktg.weather:id/pager Pager class: class android.support.v4.view.ViewPager Problematic adapter: class com.sparktg.weather.TabsAdapter
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1 回答 1

1

我想出了我的错误。我试图在不提供要显示的备用选项卡的情况下删除当前选项卡。在这种情况下，用户可能已经删除了所有选项卡，这是不可取的。因此，在我的适配器的 removeTab() 方法中，我只是在删除当前/任何其他选项卡之前将当前视图设置为某个默认选项卡。但是，在这种情况下，用户不应该有删除该默认选项卡的选项。

以下是我改进的方法：

public void removeTab(ArrayList<String> tabNames){
    Log.v(TAG, "Inside removeTab method of TabsAdpater");
    Log.v(TAG, "Current Tab is at position " + mViewPager.getCurrentItem());
    mViewPager.setCurrentItem(0);
    Log.v(TAG, "Current Item is now set at position " + mViewPager.getCurrentItem());
    for (int i=1; i<mTabNames.size(); i++){
        for (int j=0;j<tabNames.size();j++){
            if(tabNames.get(j).equals(mTabList.get(i).getText().toString())){
                Log.v(TAG, "Tabs to be removed are : " + tabNames.get(j));
                mTabs.remove(mTabList.get(i).getTag());
                mActionBar.removeTab(mTabList.get(i));
                mTabNames.remove(mTabList.get(i).getText());
                mTabList.remove(mTabList.get(i));
                notifyDataSetChanged();                 
            }
        }
    }
}
于 2013-07-02T05:59:53.363 回答