按鈕和菜單在方向更改後停止工作

Question

我有一個使用選項卡和片段進行導航的Android應用程序。該應用程序在啓動時工作正常，但在更改方向後，碎片中的菜單項和小部件停止工作。如果我在清單中放入 android:configChanges="orientation|screenSize" ，但在Android文檔中它說這應該是最後一招，所以我想知道是否有更好的解決方案。以下是主機活動的代碼和其中一個片段。

package com.mynews; 

import android.app.ActionBar; 
import android.app.ActionBar.Tab; 
import android.app.Activity; 
import android.app.Fragment; 
import android.app.FragmentTransaction; 
import android.os.Bundle; 
import android.view.Menu; 

public class MainActivity extends Activity { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     //setContentView(R.layout.activity_main); 
     //stopService(new Intent(this, FindArticlesService.class)); 
     ActionBar actionBar = getActionBar(); 
     actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); 
     Tab tab = actionBar.newTab() 
       .setText("Articles") 
       .setTabListener(new TabListener<Articles>(this, "articles", Articles.class)); 
     actionBar.addTab(tab); 
     tab = actionBar.newTab() 
       .setText("Websites") 
       .setTabListener(new TabListener<UserSites>(this, "websites", UserSites.class)); 
     actionBar.addTab(tab); 
     tab = actionBar.newTab() 
       .setText("Add a website") 
       .setTabListener(new TabListener<AddSites>(this, "add a site", AddSites.class)); 
     actionBar.addTab(tab); 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     //getMenuInflater().inflate(R.menu.main, menu); 
     return true; 
    } 

    @Override 
    protected void onSaveInstanceState(Bundle outState) { 
     // TODO Auto-generated method stub 
     super.onSaveInstanceState(outState); 
    } 

    @Override 
    protected void onDestroy() { 
     // TODO Auto-generated method stub 
     super.onDestroy(); 
     ////Intent intent = new Intent(this, FindArticlesService.class); 
     //this.startService(intent); 
    } 

    public static class TabListener<T extends Fragment> implements ActionBar.TabListener { 
     Fragment fragment; 
     final Activity activity; 
     final String tag; 
     final Class<T> mClass; 

     public TabListener(Activity a, String s, Class<T> c){ 
      activity = a; 
      tag = s; 
      mClass = c; 
     } 

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

     } 

     @Override 
     public void onTabSelected(Tab tab, FragmentTransaction ft) { 
      // TODO Auto-generated method stub 
      if(fragment == null){ 
       fragment = Fragment.instantiate(activity, mClass.getName()); 
       ft.add(android.R.id.content, fragment, tag); 
      }else{ 
       ft.attach(fragment); 
      } 
     } 

     @Override 
     public void onTabUnselected(Tab tab, FragmentTransaction ft) { 
      // TODO Auto-generated method stub 
      if(fragment != null){ 
       ft.detach(fragment); 
      } 
      activity.closeContextMenu(); 
     } 

    } 

} 

我的片段

類

package com.mynews; 

import java.io.FileInputStream; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.ObjectInputStream; 
import java.io.ObjectOutputStream; 
import java.net.MalformedURLException; 
import java.util.ArrayList; 

import android.app.AlertDialog; 
import android.app.Dialog; 
import android.app.DialogFragment; 
import android.app.Fragment; 
import android.content.Context; 
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.View.OnClickListener; 
import android.view.ViewGroup; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.Toast; 

public class AddSites extends Fragment { 

    public AddSites(){} 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     //setContentView(R.layout.activity_add_sites); 
     // Show the Up button in the action bar. 
     setHasOptionsMenu(true); 
    } 

    @Override 
    public void onActivityCreated(Bundle savedInstanceState) { 
     // TODO Auto-generated method stub 
     super.onActivityCreated(savedInstanceState); 
     Button button = (Button) getActivity().findViewById(R.id.add); 
     button.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       // TODO Auto-generated method stub 
       UserSitesFunc usf = new UserSitesFunc(); //create a new UserSitesFunc to hold 
       try{         //the list of sites 
        FileInputStream fis = getActivity().openFileInput("MySites.ser");//check if there's a file 
        ObjectInputStream ois = new ObjectInputStream(fis);//with a USF object 
        usf = (UserSitesFunc) ois.readObject(); //if there is, deserialize it and use it 
        ois.close();//instead of a brand new object 
       }catch(IOException e){ //catch various exceptions 
        e.printStackTrace(); 
       }catch(Exception ep){ 
        ep.printStackTrace(); 
       }finally{ 
       try{ //do this with either the new object or the deserialised one 
        EditText website = (EditText) getActivity().findViewById(R.id.editText1);//get the input 
        EditText keywords = (EditText) getActivity().findViewById(R.id.editText2);//from the user 
        String web = website.getText().toString(); //store it in strings 
        String key = keywords.getText().toString(); 
        String[] kwords = key.split(", "); 
        ArrayList<String> newKeywords = new ArrayList<String>(); 
        for(String s:kwords){ 
         newKeywords.add(s); 
        } 
        Sites s = new Sites(web, newKeywords);//create a new site from the input 
        if(usf.siteList.contains(s)){ 
         showContainedDialog(); 
         return; 
        } 
        usf.addSite(s);//add it to the user's list of sites 
        FileOutputStream fs = getActivity().openFileOutput("MySites.ser", Context.MODE_PRIVATE);//save it 
        ObjectOutputStream oos = new ObjectOutputStream(fs); 
        oos.writeObject(usf); 
        oos.close(); 
        Toast.makeText(getActivity(), web + " added to Tracked Websites", Toast.LENGTH_LONG).show(); 
        website.setText(""); 
        keywords.setText(""); 
       }catch(MalformedURLException mue){ 
        showDialog(); 
       }catch(Exception ex){ 
        ex.printStackTrace(); 
       } 
       } 
      } 
     }); 
    } 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
      Bundle savedInstanceState) { 
     // TODO Auto-generated method stub 
     View view = inflater.inflate(R.layout.activity_add_sites, container, false); 
     return view; 
    } 

    @Override 
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { 
     menu.clear(); 
     inflater.inflate(R.menu.add_sites, menu); 
     super.onCreateOptionsMenu(menu, inflater); 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     switch (item.getItemId()) { 
     case android.R.id.home: 
      // This ID represents the Home or Up button. In the case of this 
      // activity, the Up button is shown. Use NavUtils to allow users 
      // to navigate up one level in the application structure. For 
      // more details, see the Navigation pattern on Android Design: 
      // 
      // http://developer.android.com/design/patterns/navigation.html#up-vs-back 
      // 
      return true; 
     } 
     return super.onOptionsItemSelected(item); 
    } 

    public static class NotAWebsiteDialog extends DialogFragment { 
     public static NotAWebsiteDialog newInstance(){ 
      NotAWebsiteDialog notAWebsite = new NotAWebsiteDialog(); 
      Bundle args = new Bundle(); 
      notAWebsite.setArguments(args); 
      return notAWebsite; 
     } 

     @Override 
     public Dialog onCreateDialog(final Bundle savedInstanceState) { 
      // TODO Auto-generated method stub 
      return new AlertDialog.Builder(getActivity()) 
      .setMessage("Please enter a vaild web address") 
      .create(); 

     } 
    } 

    public void showDialog(){ 
     DialogFragment dialog = NotAWebsiteDialog.newInstance(); 
     dialog.show(getFragmentManager(), "Not A Website"); 
    } 

    public static class AlreadyContainsWebsiteDialog extends DialogFragment { 
     public static AlreadyContainsWebsiteDialog newInstance(){ 
      AlreadyContainsWebsiteDialog containsAWebsite = new AlreadyContainsWebsiteDialog(); 
      Bundle args = new Bundle(); 
      containsAWebsite.setArguments(args); 
      return containsAWebsite; 
     } 

     @Override 
     public Dialog onCreateDialog(final Bundle savedInstanceState) { 
      // TODO Auto-generated method stub 
      return new AlertDialog.Builder(getActivity()) 
      .setMessage("This website is already being tracked") 
      .create(); 

     } 
    } 

    public void showContainedDialog(){ 
     DialogFragment dialog = AlreadyContainsWebsiteDialog.newInstance(); 
     dialog.show(getFragmentManager(), "Contains this Website"); 
    } 

} 

Answer 1

榮譽不採取討巧...跟上你的編程努力！

請參閱my answer here關於使用菜單及其主機碎片。