Android 对多个对象使用泛型类（actionBar选项卡）

目前，我使用ABS、ActionBar选项卡和TabsAdapter/ViewPager为我的应用程序创建了一个漂亮的选项卡布局。我在顶部有5个以上的分类标签-最终用户将能够添加新的分类（我稍后会设置）。因此，目前，我有一个主要的

SherlockFragmentActivity

，其中包含许多

SherlockFragment

类别文件。在针对主SFA的onCreate中，我构建了actionBar并添加了所有选项卡，如下所示：

mTabsAdapter.addTab(bar.newTab().setText(R.string.login),
            LoginFragment.class, null);
    mTabsAdapter.addTab(bar.newTab().setText("Geographics"),
            GeoFragment.class, null);
    mTabsAdapter.addTab(bar.newTab().setText(R.string.economics),
            EconFragment.class, null);
    mTabsAdapter.addTab(bar.newTab().setText(R.string.elections),
            ElectionsFragment.class, null);

我想做的是创建一个新的解决方案，

CategoryFragment

，而不是使用所有特定的选举、地理位置、经济等。有人能想象一个解决方案吗理想情况下，我只想将一个字符串传递给添加的选项卡，这样CategoryFragment就可以根据该字符串进行膨胀。我喜欢这种解决方案，因为在多个类中，代码非常冗余，而类真正做的只是从SQL dB online加载内容，只获取其自身类别的数据

这是我的TabsAdapter类：

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

    final class TabInfo {
        private final Class<?> clss;
        private final Bundle args;
        //private final String title;
                    //This string is implemented only as part of my attempt!

        TabInfo(Class<?> _class, Bundle _args, String _title) {
            clss = _class;
            args = _args;
            title = _title;
        }
    }
    /*Constructor method that adds a TabsAdapter to each tab that is created.
     * It also adds the ViewPager to each tab so that the user can swipe to change tabs.
     */
    public TabsAdapter(SherlockFragmentActivity activity, ViewPager pager) {
        super(activity.getSupportFragmentManager());
        mContext = activity;
        this.activity = (Polling) activity;
        mActionBar = activity.getSupportActionBar();
        mViewPager = pager;
        mViewPager.setAdapter(this);
        mViewPager.setOnPageChangeListener(this);
    }

    /*This is the method I've been trying to use to solve the problem, but it's not really cutting it!*/

    public void buildTabs() throws ClassNotFoundException { 
        String [] tabs = {"Econ", "Elections", "Geo", "Politics", "Science", "Finance", "Religion", 
                "Military", "International" };
        final String resource = "R.string.";            
        mTabsAdapter.addTab(bar.newTab().setText("Login"),
                LoginFragment.class, null, "Login");
        for (int j = 0; j < tabs.length; j++) {
            String res = resource + tabs[j];
            String clas = tabs[j] + "Fragment";
            String total = "com.davekelley.polling." + clas;
        mTabsAdapter.addTab(bar.newTab().setText(tabs[j]),
                CategoryFragment.class, null, tabs[j]);
        }           
    }

    /*A fairly simple method that sets the TabInfo for each tab so that the TabsAdapter
     * knows which class the tab that is being added actually belonds to. It also updates
     * the UI interface when each tab is added. 
     */

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

    public int getCount() {
        return mTabs.size();
    }
    /*A method that is used in other classes to allow each tab Fragment to 
     * access its inherited methods from a mother-class, in this case, SherlockFragment
     */

    public int getPosition(SherlockFragment fragment) {
        for (int j = 1; j < mTabs.size(); j++) {
            TabInfo info = (TabInfo) mActionBar.getTabAt(j).getTag();
            if (info.title.matches(mTabs.get(j).title)) {
                return j;
            }
        }
        return -1;


    }
    public SherlockFragment getItem(int position) {
        TabInfo info = mTabs.get(position);
        return (SherlockFragment)Fragment.instantiate(mContext, info.clss.getName(), info.args);
    }
    /*This method reads the user's selection for a new tab and sets that tab as
     * the new current focus.*/
    public void onPageSelected(int position) {
        mActionBar.setSelectedNavigationItem(position);
        selectInSpinnerIfPresent(position, true);
    }

    private void selectInSpinnerIfPresent(int position, boolean animate) {
        try {
            View actionBarView = findViewById(R.id.abs__action_bar);
            if (actionBarView == null) {
                int id = getResources().getIdentifier("action_bar", "id", "android");
                actionBarView = findViewById(id);
            }

            Class<?> actionBarViewClass = actionBarView.getClass();
            Field mTabScrollViewField = actionBarViewClass.getDeclaredField("mTabScrollView");
            mTabScrollViewField.setAccessible(true);

            Object mTabScrollView = mTabScrollViewField.get(actionBarView);
            if (mTabScrollView == null) {
                return;
            }

            Field mTabSpinnerField = mTabScrollView.getClass().getDeclaredField("mTabSpinner");
            mTabSpinnerField.setAccessible(true);

            Object mTabSpinner = mTabSpinnerField.get(mTabScrollView);
            if (mTabSpinner == null) {
                return;
            }

            Method setSelectionMethod = mTabSpinner.getClass().getSuperclass().getDeclaredMethod("setSelection", Integer.TYPE, Boolean.TYPE);
            setSelectionMethod.invoke(mTabSpinner, position, animate);

        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
    }

    public void onPageScrollStateChanged(int state) {}
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {}
    /* This is the method that actually draws the newest tab onto the screen when
     * it is selected.*/
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        mViewPager.setCurrentItem(tab.getPosition());

        sp = getSharedPreferences("prefs", MODE_PRIVATE);
        SharedPreferences.Editor preferencesEditor = sp.edit();
        preferencesEditor.putInt("lastPosition", mViewPager.getCurrentItem());
        preferencesEditor.commit();
    }
    public void onTabUnselected(Tab tab, FragmentTransaction ft) {}
    public void onTabReselected(Tab tab, FragmentTransaction ft) {}
    public void onTabReselected(Tab tab, android.app.FragmentTransaction ft) {}
    public void onTabUnselected(Tab tab, android.app.FragmentTransaction ft) {}
}

公共类TabsAdapter扩展了FragmentPagerAdapter
实现ActionBar.TablListener、ViewPager.OnPageChangeListener{
私有最终上下文mContext；
私人投票活动；
私人终审法院；
专用最终查看页面mViewPager；
private final ArrayList mtab=new ArrayList（）；
最后一个类TabInfo{
私人期末班；
私有最终包args；
//私人最终字符串标题；
//此字符串仅作为我尝试的一部分实现！
TabInfo（类、包、参数、字符串、标题）{
clss=_类；
args=_args；
title=_title；
}
}
/*构造函数方法，该方法向创建的每个选项卡添加一个TabsAdapter。
*它还将ViewPager添加到每个选项卡，以便用户可以滑动以更改选项卡。
*/
公共选项卡dapter（SherlockFragmentActivity活动、ViewPager寻呼机）{
super（activity.getSupportFragmentManager（））；
mContext=活动；
this.activity=（轮询）活动；
mActionBar=activity.getSupportActionBar（）；
mViewPager=寻呼机；
mViewPager.setAdapter（此）；
mViewPager.setOnPageChangeListener（此）；
}
/*这是我一直试图用以解决问题的方法，但它并不能真正解决问题*/
public void buildTabs（）引发ClassNotFoundException{
String[]tabs={“经济”、“选举”、“地理”、“政治”、“科学”、“金融”、“宗教”，
“军事”、“国际”}；
final String resource=“R.String。”；
MTABAdapter.addTab（bar.newTab（）.setText（“登录”），
LoginFragment.class，null，“Login”）；
对于（int j=0；jString clas = tabs[j] + "Fragment";
String total = "com.davekelley.polling." + clas;
Class<?> theClass = Class.forName (total);