碎片中的后端堆栈不起作用

时间：2014-05-13 07:57:29

标签： android android-fragments android-actionbar android-tabs back-stack

在我的MainActivity中，我添加了三个名为FragmentA，FragmentB和FragmentC的标签。

在FragmentA标签中，我通过列表片段填充联系人列表，并将此片段添加到backstack。现在，当我点击任何列表项时，它会在同一个标​​签FragmentA下显示该联系人的详细片段。当我按下后退按钮时，它会返回列出联系人列表的片段。

在详细信息片段上，而不是单击后退按钮，当我单击FragmentB选项卡时，它应该显示一个简单的文本，它正常工作。但是当我现在单击后退按钮时，它应该关闭应用程序，但它会返回到列表片段，但仍保留在FragmentB选项卡内，因此会合并这两个片段。

在我的MainActivity.java，

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

if(tab.getPosition() == 0){
    PM_Fragment pm_Fragment= new PM_Fragment();
    FragmentManager manager= getFragmentManager();
    FragmentTransaction frgTrans = manager.beginTransaction();
    frgTrans.replace(android.R.id.content, pm_Fragment);
    frgTrans.commit();
}

else    if(tab.getPosition() == 1){
    TabFragmentTwo tabFragmentTwo= new TabFragmentTwo();
    Bundle bundle = new Bundle();
    bundle.putString("Fragment", "2nd Fragment");

    tabFragmentTwo.setArguments(bundle);
    FragmentManager manager= getFragmentManager();
    FragmentTransaction frgTrans = manager.beginTransaction();
    frgTrans.replace(android.R.id.content, tabFragmentTwo);
    frgTrans.commit();
}

else {
    TabFragmentThree tabFragmentThree= new TabFragmentThree();
    Bundle bundle = new Bundle();

    bundle.putString("Fragment", "3rd Fragment");

    tabFragmentThree.setArguments(bundle);
    FragmentManager manager= getFragmentManager();
    FragmentTransaction frgTrans = manager.beginTransaction();
    frgTrans.replace(android.R.id.content, tabFragmentThree);
    frgTrans.commit();
    }

}

PM_Fragment.java显示联系人列表。 

package com.android.myactiobartabs;
import android.app.ActionBar;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.app.ListFragment;
import android.app.LoaderManager;
import android.content.CursorLoader;
import android.content.Intent;
import android.content.Loader;
import android.database.Cursor;
import android.graphics.Color;
import android.net.Uri;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.provider.ContactsContract.Contacts;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.SearchView.OnQueryTextListener;
import android.widget.SimpleCursorAdapter;
import android.widget.Toast;

public class PM_Fragment extends ListFragment 
                        implements OnQueryTextListener , LoaderManager.LoaderCallbacks<Cursor>{
    String mCurFilter;
    SimpleCursorAdapter mAdapter;

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

        ActionBar actionBar = getActivity().getActionBar();
//      actionBar.setDisplayHomeAsUpEnabled(false);
        MenuButtonUtil.enableMenuButton(getActivity());

    }
    @Override
    public View onCreateView(LayoutInflater inflater,ViewGroup container, Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.activity_list_view_with_simple_adapter, container,false);

        mAdapter = new SimpleCursorAdapter(getActivity(),
                R.layout.pm_fragment, null,
                new String[] {ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME, ContactsContract.CommonDataKinds.Phone.NUMBER},
                new int[] { R.id.textView1, R.id.textView2 }, 0);
        setListAdapter(mAdapter);

        getLoaderManager().initLoader(0, null, this);

        return rootView;
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {

        inflater.inflate(R.menu.pm_fragment_actionitems, menu);
        MenuItem searchItem = menu.findItem(R.id.pm_action_search);
        SearchView sv = new SearchView(getActivity());
    // Changing the color of Searchview widget text field to white.     
        int searchSrcTextId = getResources().getIdentifier("android:id/search_src_text", null, null);  
        EditText searchEditText = (EditText) sv.findViewById(searchSrcTextId);  
        searchEditText.setTextColor(Color.WHITE); 

        sv.setOnQueryTextListener(this);
        searchItem.setActionView(sv);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        switch (item.getItemId()) {
        case R.id.pm_action_delete:
            Toast.makeText(getActivity(),"Text_DELETE!",Toast.LENGTH_SHORT).show();
            return true;
        case R.id.pm_action_edit:
            Toast.makeText(getActivity(),"Text_EDIT!",Toast.LENGTH_SHORT).show();
            return true;
        case R.id.pm_action_add_person:
            final Intent intent = new Intent(Intent.ACTION_INSERT, Contacts.CONTENT_URI);
            startActivity(intent);
            return true;
        case R.id.pm_action_refresh:
            Toast.makeText(getActivity(),"Text_REFRESH!",Toast.LENGTH_SHORT).show();
            return true;
        default:
            return super.onOptionsItemSelected(item);
        }
    }

    @Override
    public void onListItemClick(ListView l, View v, int position, long id) {

        getListView().setItemChecked(position, true);

        DetailsFragment detailsFragment = new DetailsFragment();

        Cursor mycursor = (Cursor) getListView().getItemAtPosition(position);
        System.out.println("mycursor.getString(1) " + mycursor.getString(2) +"   ");

        Bundle bundle = new Bundle();
        bundle.putString("CONTACT_NAME",  mycursor.getString(1));
        bundle.putString("CONTACT_NUMBER",  mycursor.getString(2));

        detailsFragment.setArguments(bundle);
        FragmentManager manager= getActivity().getFragmentManager();
        FragmentTransaction frgTrans = manager.beginTransaction();
        frgTrans.replace(android.R.id.content, detailsFragment);
        frgTrans.addToBackStack("pm_fragment");
        frgTrans.commit();
    }

    @Override
    public boolean onQueryTextChange(String newText) {
        mCurFilter = !TextUtils.isEmpty(newText) ? newText : null;
        getLoaderManager().restartLoader(0, null, this);
        return true;
    }

    @Override
    public Loader<Cursor> onCreateLoader(int id, Bundle args) {

        System.out.println("The value of Filter is : "+mCurFilter); 
        // Run query
        Uri baseUri;

        if (mCurFilter != null) {
            baseUri = Uri.withAppendedPath(ContactsContract.CommonDataKinds.Phone.CONTENT_FILTER_URI,
                    Uri.encode(mCurFilter));
        } else {
            baseUri = ContactsContract.CommonDataKinds.Phone.CONTENT_URI;
        }

        String[] projection = new String[] {
                ContactsContract.CommonDataKinds.Phone._ID,
                ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME,
                ContactsContract.CommonDataKinds.Phone.NUMBER,
                }; 

        String selection = "((" + 
                ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME + " NOTNULL) AND (" +
                ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME + " != '' ))";
        String[] selectionArgs = null;
        String sortOrder = ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME + " COLLATE LOCALIZED ASC";

        return new CursorLoader(getActivity(), baseUri, projection, selection, selectionArgs, sortOrder);
    }

    @Override
    public void onLoadFinished(Loader<Cursor> arg0, Cursor data) {
        mAdapter.swapCursor(data);
    }

    @Override
    public void onLoaderReset(Loader<Cursor> arg0) {
        // TODO Auto-generated method stub
        mAdapter.swapCursor(null);      
    }

    @Override
    public boolean onQueryTextSubmit(String query) {
        // TODO Auto-generated method stub
        return false;
    }

}

DetailsFragment.java显示点击列表项的详细信息：

package com.android.myactiobartabs;

import android.app.ActionBar;
import android.app.Fragment;
import android.content.Intent;
import android.os.Bundle;
import android.provider.ContactsContract.Contacts;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;

public class DetailsFragment extends Fragment  {
    TextView textDetail1;
    TextView textDetail2;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setHasOptionsMenu(true);

        //Get ActionBar   and navigate UP
        ActionBar actionBar = getActivity().getActionBar();
        //      MenuButtonUtil.enableMenuButton(getActivity());
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.details_fragment, container, false);

        textDetail1 = (TextView)view.findViewById(R.id.textDetail1);
        textDetail2 = (TextView)view.findViewById(R.id.textDetail2);

        Bundle bundle = getArguments();
        if(bundle != null){
            String name = bundle.getString("CONTACT_NAME");
            String number = bundle.getString("CONTACT_NUMBER");
            textDetail1.setText(""+number);
            textDetail2.setText(""+name);
        }

        //      getFragmentManager().popBackStack();

        return view;
    }


    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {

        inflater.inflate(R.menu.details_fragment_actionitems, menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        switch (item.getItemId()) {

        /*case android.R.id.home:

            FragmentManager manager= getActivity().getFragmentManager();
            manager.popBackStack("pm_fragment", FragmentManager.POP_BACK_STACK_INCLUSIVE);
            FragmentTransaction frgTrans = manager.beginTransaction();
            frgTrans.commit();
            getActivity().getActionBar().setDisplayHomeAsUpEnabled(false);
            getActivity().getActionBar().setHomeButtonEnabled(false);

            return true;
         */
        case R.id.dt_action_search:
            Toast.makeText(getActivity(),"Text_SEARCH!",Toast.LENGTH_SHORT).show();
            return true;
        case R.id.dt_action_delete:
            Toast.makeText(getActivity(),"Text_DELETE!",Toast.LENGTH_SHORT).show();
            return true;
        case R.id.dt_action_edit:
            Toast.makeText(getActivity(),"Text_EDIT!",Toast.LENGTH_SHORT).show();
            return true;
        case R.id.dt_action_add_person:
            final Intent intent = new Intent(Intent.ACTION_INSERT, Contacts.CONTENT_URI);
            startActivity(intent);
            return true; 
        default:
            return super.onOptionsItemSelected(item);
        }
    }    

}

TagFragmentTwo.java点击FragmentB标签显示简单的txt。 

package com.android.myactiobartabs;

import android.app.ActionBar;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;


public class TabFragmentTwo extends Fragment{


        TextView textDetail;

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

            ActionBar actionBar = getActivity().getActionBar();

        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {


            View view = inflater.inflate(R.layout.tab_fragment, container, false);

            textDetail = (TextView)view.findViewById(R.id.simpleTxt);

            Bundle bundle = getArguments();
            if(bundle != null){
                String simpleTxt = bundle.getString("Fragment");
                textDetail.setText(""+simpleTxt);
            }

            return view;
        }


        @Override
        public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        // TODO Auto-generated method stub
        super.onCreateOptionsMenu(menu, inflater);
        }

        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
        // TODO Auto-generated method stub
        return super.onOptionsItemSelected(item);
        }

    }

1 个答案:

答案 0 :(得分：1)

我建议您在点击 2DFragment 或 3D Fragment 时清除片段的背景。在该click事件中，首先弹出片段的backstack，然后加载新片段。它肯定会起作用。

在加载新片段之前，单击选项卡编写以下代码。 

            FragmentManager fm = getSupportFragmentManager();
            FragmentTransaction ft = fm.beginTransaction();
            fm.popBackStack();

<强>编辑：

更改MainActivity中的代码，如下所示：

else    if(tab.getPosition() == 1){

    FragmentManager manager= getFragmentManager();
    FragmentTransaction frgTrans = manager.beginTransaction();
    manager.popBackStack();

      TabFragmentTwo tabFragmentTwo= new TabFragmentTwo();
    Bundle bundle = new Bundle();
    bundle.putString("Fragment", "2nd Fragment");

    tabFragmentTwo.setArguments(bundle);
    frgTrans.replace(android.R.id.content, tabFragmentTwo);
    frgTrans.commit();
}

else {
    FragmentManager manager= getFragmentManager();
    FragmentTransaction frgTrans = manager.beginTransaction();
    manager.popBackStack();
     TabFragmentThree tabFragmentThree= new TabFragmentThree();
    Bundle bundle = new Bundle();
    bundle.putString("Fragment", "3rd Fragment");

    tabFragmentThree.setArguments(bundle);

    frgTrans.replace(android.R.id.content, tabFragmentThree);
    frgTrans.commit();
    }
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