如何在子活动中显示标签？

Question

I make an application in which i had made 5 Tabs on the First Tab there is a ListView When i Click on any ListItem i had call another activity with intent .Now there us a problem As & when i click on Listitem The Tabs will Dissapears How can i show Tabs on my SubActivity .

Any help willl be Appretiated.

Answer 1

That is the normal behavior in Android, not very nice.

I usually create the first Activity in a Tab extending from this class

public class TabActivityGroup extends ActivityGroup {
    protected LocalActivityManager manager;
    protected ArrayList<String> mIdList;

    public TabActivityGroup() {
        this(false);
    }

    public TabActivityGroup(boolean single) {
        super(single);
    }

    public void onCreate(Bundle ins) {
        super.onCreate(ins);
        manager = getLocalActivityManager();
        mIdList = new ArrayList<String>();
    }

    public void startChildActivity(String Id, Intent intent) {
        Log.d(this.getClass().getName(), "startChildActivity " + Id + " / " + mIdList.size());
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        Window window = manager.startActivity(Id, intent);
        if (window != null) {
            mIdList.add(Id);
            setContentView(window.getDecorView());
        }
    }

    @Override
    public void finishFromChild(Activity child) {
        Log.d(this.getClass().getName(), "finishFromChild("+child.getClass().getName()+") mIdList.size " + mIdList.size());
        int index = mIdList.size() - 1;
        if (index < 1) {
            finish();
        }else{
            Log.e(getClass().getName(), "destroy " + mIdList.get(index));

            manager.destroyActivity(mIdList.get(index), true);
            mIdList.remove(index);
            index--;
            String lastId = mIdList.get(index);
            Activity previous = manager.getActivity(lastId);

            setContentView(previous.getWindow().getDecorView());
        }   
    }

    /**
     * Overrides the default implementation for KeyEvent.KEYCODE_BACK so that
     * all systems call onBackPressed().
     */
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            goBack();
            return true;
        }
        return super.onKeyUp(keyCode, event);
    }


    public void goBack() {
        Log.d(this.getClass().getName(), "goBACK() : " + mIdList.size());
        int length = mIdList.size();
        if (length > 1) {
            Activity current = manager.getActivity(mIdList.get(length - 1));
            current.finish();
        }else{
            ((MyApplication)getApplication()).systemExit(this);
                    //This just calls to System.exit
        }
    }
}

You can then create a Tab like this

public class TabOne extends TabActivityGroup {

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

        startChildActivity(OneActivity.class.getName(), new Intent(this, OneActivity.class));
    }

Things to keep in mind:

• The tab has nothing inside, just starts the real tab activity with
  the startChildActivity method. This is to get a nice behavior when going back and reach the first activity and the app needs to close.

• Be very careful with the Context on the subactivities as you have
  to use the TabActivityGroup context. You can do this manually by
  calling getParent() , or better defining a method that loops calling getParent() until you find the root parent.