Android Studioでナビゲーションメニューを追加した後にアプリケーションがクラッシュする

Question

ナビゲーションメニューを追加した後、私のソースコードを見て、私のアプリがクラッシュしました。何が間違っているのか教えてください。Googleで検索していて、この問題の解決策には到着できませんでしたか？ありがとうございました。

のように私のMainActivityに見える：

<?xml version="1.0" encoding="utf-8"?> 
<android.support.v4.widget.DrawerLayout 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/drawer_layout" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    > 

    <FrameLayout 
     android:id="@+id/content_frame" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" /> 


    <ListView 
     android:id="@+id/left_drawer" 
     android:layout_width="240dp" 
     android:layout_height="match_parent" 
     android:layout_gravity="start" 
     android:choiceMode="singleChoice" 
     android:divider="@android:color/transparent" 
     android:dividerHeight="0dp" 
     android:background="#ccc"/> 

</android.support.v4.widget.DrawerLayout> 

Drawer_list_item.xmlは、次のようになります：

<TextView xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@android:id/text1" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:textAppearance="?android:attr/textAppearanceListItemSmall" 
    android:gravity="center_vertical" 
    android:paddingLeft="16dp" 
    android:paddingRight="16dp" 
    android:textColor="#113d5e" 
    android:background="?android:attr/activatedBackgroundIndicator" 
    android:minHeight="?android:attr/listPreferredItemHeightSmall"/> 

Fragment_content.xmlは、次のようになります。

私Activity_main.xmlがどのように見える

package com.example.rssreader; 
import android.app.Fragment; 
import android.app.FragmentManager; 
import android.app.SearchManager; 
import android.content.Intent; 
import android.content.res.Configuration; 
import android.os.Bundle; 
import android.support.v4.view.GravityCompat; 
import android.support.v4.widget.DrawerLayout; 
import android.support.v7.app.AppCompatActivity; 
import android.support.v7.widget.RecyclerView; 
import android.support.v7.widget.Toolbar; 
import android.support.v7.app.ActionBar; 
import android.view.LayoutInflater; 
import android.view.MenuInflater; 
import android.view.View; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.ViewGroup; 
import android.widget.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.ImageView; 
import android.widget.ListView; 
import android.widget.Toast; 

import java.util.Locale; 

public class MainActivity extends AppCompatActivity { 
    private DrawerLayout mDrawerLayout; 
    private ListView mDrawerList; 
    private android.support.v4.app.ActionBarDrawerToggle mDrawerToggle; 

    private CharSequence mDrawerTitle; 
    private CharSequence mTitle; 
    private String[] mPlanetTitles; 
    RecyclerView recyclerView; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 


     recyclerView = (RecyclerView) findViewById(R.id.recyclerview); 
     ReadRss readRss = new ReadRss(this, recyclerView); 
     readRss.execute(); 

     mTitle = mDrawerTitle = getTitle(); 
     mPlanetTitles = getResources().getStringArray(R.array.contents); 
     mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout); 
     mDrawerList = (ListView) findViewById(R.id.left_drawer); 

     getSupportActionBar().setDisplayHomeAsUpEnabled(true); 
     getSupportActionBar().setHomeButtonEnabled(true); 

     // set a custom shadow that overlays the main content when the drawer opens 
     mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START); 
     // set up the drawer's list view with items and click listener 
     mDrawerList.setAdapter(new ArrayAdapter<String>(this, 
       R.layout.drawer_list_item, mPlanetTitles)); 
     mDrawerList.setOnItemClickListener(new DrawerItemClickListener()); 

     // enable ActionBar app icon to behave as action to toggle nav drawer 


     // ActionBarDrawerToggle ties together the the proper interactions 
     // between the sliding drawer and the action bar app icon 
     mDrawerToggle = new android.support.v4.app.ActionBarDrawerToggle(
       this,     /* host Activity */ 
       mDrawerLayout,   /* DrawerLayout object */ 
       R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */ 
       R.string.drawer_open, /* "open drawer" description for accessibility */ 
       R.string.drawer_close /* "close drawer" description for accessibility */ 
     ) { 
      public void onDrawerClosed(View view) { 
       getActionBar().setTitle(mTitle); 
       invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu() 
      } 

      public void onDrawerOpened(View drawerView) { 
       getActionBar().setTitle(mDrawerTitle); 
       invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu() 
      } 
     }; 
     mDrawerLayout.setDrawerListener(mDrawerToggle); 

     if (savedInstanceState == null) { 
      selectItem(0); 
     } 

     getWindow().setNavigationBarColor(getResources().getColor(R.color.colorPrimary)); 



    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     MenuInflater inflater = getMenuInflater(); 
     inflater.inflate(R.layout.main, menu); 
     return super.onCreateOptionsMenu(menu); 
    } 

    /* Called whenever we call invalidateOptionsMenu() */ 
    @Override 
    public boolean onPrepareOptionsMenu(Menu menu) { 
     // If the nav drawer is open, hide action items related to the content view 
     boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList); 
     menu.findItem(R.id.action_websearch).setVisible(!drawerOpen); 
     return super.onPrepareOptionsMenu(menu); 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // The action bar home/up action should open or close the drawer. 
     // ActionBarDrawerToggle will take care of this. 
     if (mDrawerToggle.onOptionsItemSelected(item)) { 
      return true; 
     } 
     // Handle action buttons 
     switch(item.getItemId()) { 
      case R.id.action_websearch: 
       // create intent to perform web search for this planet 
       Intent intent = new Intent(Intent.ACTION_WEB_SEARCH); 
       // catch event that there's no activity to handle intent 
       if (intent.resolveActivity(getPackageManager()) != null) { 
        startActivity(intent); 
       } else { 
        Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show(); 
       } 
       return true; 
      default: 
       return super.onOptionsItemSelected(item); 
     } 
    } 

    /* The click listner for ListView in the navigation drawer */ 
    private class DrawerItemClickListener implements ListView.OnItemClickListener { 
     @Override 
     public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
      selectItem(position); 
     } 
    } 

    private void selectItem(int position) { 
     // update the main content by replacing fragments 
     Fragment fragment = new PlanetFragment(); 
     Bundle args = new Bundle(); 
     args.putInt(PlanetFragment.ARG_CONTENT_NUMBER, position); 
     fragment.setArguments(args); 

     FragmentManager fragmentManager = getFragmentManager(); 
     fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit(); 

     // update selected item and title, then close the drawer 
     mDrawerList.setItemChecked(position, true); 
     setTitle(mPlanetTitles[position]); 
     mDrawerLayout.closeDrawer(mDrawerList); 
    } 

    @Override 
    public void setTitle(CharSequence title) { 
     mTitle = title; 
     getActionBar().setTitle(mTitle); 
    } 

    /** 
    * When using the ActionBarDrawerToggle, you must call it during 
    * onPostCreate() and onConfigurationChanged()... 
    */ 

    @Override 
    protected void onPostCreate(Bundle savedInstanceState) { 
     super.onPostCreate(savedInstanceState); 
     // Sync the toggle state after onRestoreInstanceState has occurred. 
     mDrawerToggle.syncState(); 
    } 

    @Override 
    public void onConfigurationChanged(Configuration newConfig) { 
     super.onConfigurationChanged(newConfig); 
     // Pass any configuration change to the drawer toggls 
     mDrawerToggle.onConfigurationChanged(newConfig); 
    } 

    /** 
    * Fragment that appears in the "content_frame", shows a planet 
    */ 
    public static class PlanetFragment extends Fragment { 
     public static final String ARG_CONTENT_NUMBER = "planet_number"; 

     public PlanetFragment() { 
      // Empty constructor required for fragment subclasses 
     } 

     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, 
           Bundle savedInstanceState) { 
      View rootView = inflater.inflate(R.layout.fragment_content, container, false); 
      int i = getArguments().getInt(ARG_CONTENT_NUMBER); 
      String planet = getResources().getStringArray(R.array.contents)[i]; 

      int imageId = getResources().getIdentifier(planet.toLowerCase(Locale.getDefault()), 
        "drawable", getActivity().getPackageName()); 
      ((ImageView) rootView.findViewById(R.id.image)).setImageResource(imageId); 
      getActivity().setTitle(planet); 
      return rootView; 

     } 
    } 

} 

<ImageView xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/image" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:background="#000000" 
    android:gravity="center" 
    android:padding="32dp" /> 

Main.xmlは、次のようになります。

<ImageView xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/image" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:background="#000000" 
    android:gravity="center" 
    android:padding="32dp" /> 

は、私は、ナビゲーション引き出しのために別のクラスを作成することによって、その問題を解決することができたあなたに

Answer 1

ありがとうございます。しかし、私はRssFeedsの別の問題に直面しています。 。

ReadRssは、デバッグを実行するときにアプリがクラッシュしたときにエラーが指している場所AsyncTaskとrecyclerView.setLayoutManager（新しいLinearLayoutManager（コンテキスト）が拡張するパブリッククラスは

ここではReadRss.javaです：

package tk.mattercast.myapplication; 

import android.app.ProgressDialog; 
import android.content.Context; 
import android.os.AsyncTask; 
import android.support.v7.widget.LinearLayoutManager; 
import android.support.v7.widget.RecyclerView; 

import org.w3c.dom.Document; 
import org.w3c.dom.Element; 
import org.w3c.dom.Node; 
import org.w3c.dom.NodeList; 

import java.io.InputStream; 
import java.net.HttpURLConnection; 
import java.net.URL; 
import java.util.ArrayList; 

import javax.xml.parsers.DocumentBuilder; 
import javax.xml.parsers.DocumentBuilderFactory; 


public class ReadRss extends AsyncTask<Void, Void, Void> { 
    Context context; 
    String address = "http://www.oecd.org/corruption/index.xml"; 
    ProgressDialog progressDialog; 
    ArrayList<FeedItem>feedItems; 
    RecyclerView recyclerView; 
    URL url; 
    public ReadRss(Context context,RecyclerView recyclerView) { 
     this.recyclerView=recyclerView; 
     this.context = context; 
     progressDialog = new ProgressDialog(context); 
     progressDialog.setMessage("Fetching Data..."); 
    } 

    @Override 
    protected void onPreExecute() { 
     progressDialog.show(); 
     super.onPreExecute(); 
    } 

    @Override 
    protected void onPostExecute(Void aVoid) { 
     super.onPostExecute(aVoid); 
     progressDialog.dismiss(); 
     MyAdapter adapter=new MyAdapter(context,feedItems); 
     recyclerView.setLayoutManager(new LinearLayoutManager(context) { 
      @Override 
      public RecyclerView.LayoutParams generateDefaultLayoutParams() { 
       return null; 
      } 
     }); 
     recyclerView.addItemDecoration(new VerticalSpace(50)); 
     recyclerView.setAdapter(adapter); 

    } 

    @Override 
    protected Void doInBackground(Void... params) { 
     ProcessXml(Getdata()); 

     return null; 
    } 

    private void ProcessXml(Document data) { 
     if (data != null) { 
      feedItems=new ArrayList<>(); 
      Element root = data.getDocumentElement(); 
      Node channel = root.getChildNodes().item(1); 
      NodeList items = channel.getChildNodes(); 
      for (int i = 0; i < items.getLength(); i++) { 
       Node cureentchild = items.item(i); 
       if (cureentchild.getNodeName().equalsIgnoreCase("item")) { 
        FeedItem item=new FeedItem(); 
        NodeList itemchilds = cureentchild.getChildNodes(); 
        for (int j = 0; j < itemchilds.getLength(); j++) { 
         Node cureent = itemchilds.item(j); 
         if (cureent.getNodeName().equalsIgnoreCase("title")){ 
          item.setTitle(cureent.getTextContent()); 
         }else if (cureent.getNodeName().equalsIgnoreCase("description")){ 
          item.setDescription(cureent.getTextContent()); 
         }else if (cureent.getNodeName().equalsIgnoreCase("pubDate")){ 
          item.setPubDate(cureent.getTextContent()); 
         }else if (cureent.getNodeName().equalsIgnoreCase("link")){ 
          item.setLink(cureent.getTextContent()); 
         } 
        } 
        feedItems.add(item); 





       } 
      } 
     } 
    } 

    public Document Getdata() { 
     try { 
      url = new URL(address); 
      HttpURLConnection connection = (HttpURLConnection) url.openConnection(); 
      connection.setRequestMethod("GET"); 
      InputStream inputStream = connection.getInputStream(); 
      DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance(); 
      DocumentBuilder builder = builderFactory.newDocumentBuilder(); 
      Document xmlDoc = builder.parse(inputStream); 
      return xmlDoc; 
     } catch (Exception e) { 
      e.printStackTrace(); 
      return null; 
     } 
    } 


}