Android：在片段中确定选定的actionbar选项卡

Question

我正在处理一个项目，其中有数据要在列表视图中显示。我的数据有六个类别，由数据库中包含数字0-5的文本字段标识。我已经创建了一个启用选项卡导航的操作栏。我有所有项目的标签和6个6个类别的每一个共7个标签。

我已经创建了一个ListFragment来显示数据。我为每个选项卡创建了一个ListFragment实例，并通过选项卡监听器更改选项卡。我想通过类别筛选数据，我需要一种方法来确定哪个选项卡实例化了ListFragment。

public class MainActivity extends ActionBarActivity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Initialize action bar
    final ActionBar actionBar = getSupportActionBar();

    // set action bar defaults
    actionBar.setDisplayHomeAsUpEnabled(false);
    actionBar.setDisplayUseLogoEnabled(true);;
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    // set up action bar tabs
    Tab AllTab = actionBar.newTab().setText("All Items");
    Tab Cat0Tab = actionBar.newTab().setText("Category 0");
    Tab Cat1Tab = actionBar.newTab().setText("Category 1");
    Tab Cat2Tab = actionBar.newTab().setText("Category 2");
    Tab Cat3Tab = actionBar.newTab().setText("Category 3");
    Tab Cat4Tab = actionBar.newTab().setText("category 4");
    Tab Cat5Tab = actionBar.newTab().setText("Category 5");                     

    // create the fragments for each tab
    ListFragment allFragment = new ItemListFragment();
    ListFragment cat0Fragment = new ItemListFragment(); 
    ListFragment cat1Fragment = new ItemListFragment();
    ListFragment cat2Fragment = new ItemListFragment();
    ListFragment cat3Fragment = new ItemListFragment();
    ListFragment cat4Fragment = new ItemListFragment();
    ListFragment cat5Fragment = new ItemListFragment();

    // set the tab listener for each tab
    AllTab.setTabListener(new MyTabsListener(allFragment));
    Cat0Tab.setTabListener(new MyTabsListener(cat0Fragment));
    Cat1Tab.setTabListener(new MyTabsListener(cat1Fragment));
    Cat2Tab.setTabListener(new MyTabsListener(cat2Fragment));
    Cat3Tab.setTabListener(new MyTabsListener(cat3Fragment));
    Cat4Tab.setTabListener(new MyTabsListener(cat4Fragment));
    Cat5Tab.setTabListener(new MyTabsListener(cat5Fragment));       

    // Add tabs to action bar
    actionBar.addTab(AllTab);
    actionBar.addTab(Cat0Tab);
    actionBar.addTab(Cat1Tab);
    actionBar.addTab(Cat2Tab);
    actionBar.addTab(Cat3Tab);
    actionBar.addTab(Cat4Tab);
    actionBar.addTab(Cat5Tab);

    if (savedInstanceState != null) {
        actionBar.setSelectedNavigationItem(savedInstanceState.getInt("tabState"));
    }   
}   

class MyTabsListener implements ActionBar.TabListener {
    private Fragment fragment;

    public MyTabsListener(ListFragment fragment) {
        this.fragment = fragment;
    }

    @Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        ft.replace(android.R.id.content, fragment);;    
    }

    @Override
    public void onTabUnselected(Tab tab, FragmentTransaction ft) {

        if (fragment != null) {
            FragmentManager fm = getSupportFragmentManager();
            if (fm.getBackStackEntryCount()>0) {
                fm.popBackStack(fm.getBackStackEntryAt(0).getName(), FragmentManager.POP_BACK_STACK_INCLUSIVE);
            }
            ft.remove(fragment);
        }           
    }

    @Override
    public void onTabReselected(Tab tab,FragmentTransaction ft) {
        // TODO Auto-generated method stub      
    }       
}

    @Override
public void onActivityCreated(Bundle savedState) {
    super.onActivityCreated(savedState);

    mActivity = getActivity();
    db = new DataAdapter(mActivity);
    db.open();      

    // Get all of the records from the database and create the materials ListAdapter
    switch(Integer.parseInt(mTag)) {
    case 6:
        cursor = db.getAllRecords();
        break;
    default:
        cursor = db.getRecordCat(mTag);
        break;
    }

    String[] from = new String[] { DataAdapter.KEY_TITLE };
    int[] to = new int[] {R.id.item_title }; 


    // Now create an array adapter and set it to display using our row
    items = new MyListAdapter(getActivity(), R.layout.item_cell, cursor, from, to);


    // get the listview
    ListView listview = getListView();
    listview.setAdapter(items);
}

任何想法或建议都将不胜感激。

Answer 1

我认为让每个片段知道它的数字的最好方法是将数字作为参数传递给片段的构造函数。