佈局Inflater在片段中的錯誤

Question

我正在使用片段創建UI。在onCreate（Bundle savedInstanceState）中，我解析了JSON數據。我收到以下錯誤：

07-17 15:23:18.089: W/System.err(1368): at android.os.Looper.loop(Looper.java:132) 07-17 15:23:18.129: E/AndroidRuntime(1368): FATAL EXCEPTION: main 07-17 15:23:18.129: E/AndroidRuntime(1368): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.afghanread.android/com.afghanread.android.AfghanMagActivity}: android.view.InflateException: Binary XML file line #8: Error inflating class fragment 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1748) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1764) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.app.ActivityThread.access$1500(ActivityThread.java:122) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1002) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.os.Handler.dispatchMessage(Handler.java:99) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.os.Looper.loop(Looper.java:132) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.app.ActivityThread.main(ActivityThread.java:4025) 07-17 15:23:18.129: E/AndroidRuntime(1368): at java.lang.reflect.Method.invokeNative(Native Method) 07-17 15:23:18.129: E/AndroidRuntime(1368): at java.lang.reflect.Method.invoke(Method.java:491) 07-17 15:23:18.129: E/AndroidRuntime(1368): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841) 07-17 15:23:18.129: E/AndroidRuntime(1368): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599) 07-17 15:23:18.129: E/AndroidRuntime(1368): at dalvik.system.NativeStart.main(Native Method) 07-17 15:23:18.129: E/AndroidRuntime(1368): Caused by: android.view.InflateException: Binary XML file line #8: Error inflating class fragment 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:688) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.view.LayoutInflater.rInflate(LayoutInflater.java:724) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.view.LayoutInflater.inflate(LayoutInflater.java:479) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.view.LayoutInflater.inflate(LayoutInflater.java:391) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.view.LayoutInflater.inflate(LayoutInflater.java:347) 07-17 15:23:18.129: E/AndroidRuntime(1368): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:223) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.app.Activity.setContentView(Activity.java:1780) 07-17 15:23:18.129: E/AndroidRuntime(1368): at com.afghanread.android.AfghanMagActivity.onCreate(AfghanMagActivity.java:26) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1048) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1712) 07-17 15:23:18.129: E/AndroidRuntime(1368): ... 11 more 07-17 15:23:18.129: E/AndroidRuntime(1368): Caused by: java.lang.NullPointerException 07-17 15:23:18.129: E/AndroidRuntime(1368): at org.json.JSONTokener.nextCleanInternal(JSONTokener.java:112) 07-17 15:23:18.129: E/AndroidRuntime(1368): at org.json.JSONTokener.nextValue(JSONTokener.java:90) 07-17 15:23:18.129: E/AndroidRuntime(1368): at org.json.JSONObject.(JSONObject.java:154) 07-17 15:23:18.129: E/AndroidRuntime(1368): at org.json.JSONObject.(JSONObject.java:171) 07-17 15:23:18.129: E/AndroidRuntime(1368): at com.afghanread.android.CategoryFragment.parseJSON(CategoryFragment.java:72) 07-17 15:23:18.129: E/AndroidRuntime(1368): at com.afghanread.android.CategoryFragment.onCreateView(CategoryFragment.java:161) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:713) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:905) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.app.FragmentManagerImpl.addFragment(FragmentManager.java:983) 07-17 15:23:18.129: E/AndroidRuntime(1368): at android.app.Activity.onCreateView(Activity.java:4141)

我的代碼是：

public class CategoryFragment extends Fragment implements OnItemClickListener { 

ArrayList<String> cat = new ArrayList<String>(); 
ListView list; 
DatabaseManager manager; 
static String DATABASE_NAME = "afghanread.sqlite"; 
static Integer DATABASE_VERSION = 1; 
TextView text; 
TextView cat_name; 
int length; 
String[] values = new String[] { "Android", "iPhone", "WindowsMobile", 
     "Blackberry", "WebOS", "Ubuntu", "Windows7", "Max OS X", "Linux", 
     "OS/2" }; 

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

} 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    parseJSON(); 
    manager = new DatabaseManager(null, DATABASE_NAME, null, 
      DATABASE_VERSION); 

} 

private void parseJSON() { 
    try { 
     JSONObject jObject = new JSONObject(getJSONData()); 
     JSONArray jArray = jObject.getJSONArray("data"); 
     length = jArray.length(); 
     for (int i = 0; i < length; i++) { 
      JSONObject tmpJson = jArray.getJSONObject(i); 
      Category category = new Category(); 

      category.setCategotyId(tmpJson.getInt("category_id")); 
      category.setCategoryName(tmpJson.getString("category_name")); 

      // manager.insertCategoryDetails(category); 

     } 
     System.out.println("Jason parsing successful......."); 
    } catch (JSONException e) { 

     e.printStackTrace(); 
    } 
} 

private String getJSONData() { 
    HttpPost httpPost = null; 
    HttpClient httpClient = null; 
    HttpResponse httpResponse = null; 
    HttpEntity entity = null; 
    InputStream in = null; 
    BufferedReader reader = null; 
    StringBuilder sb = null; 
    String line = null; 
    String result = null; 
    try { 
     httpPost = new HttpPost(
       "http://183.182.84.197:88/Sayyed_fahim/mobile/category.php"); 
     httpClient = new DefaultHttpClient(); 
     httpResponse = httpClient.execute(httpPost); 
     int statusCode = httpResponse.getStatusLine().getStatusCode(); 
     if (statusCode == 200) { 
      entity = httpResponse.getEntity(); 
      in = entity.getContent(); 
      reader = new BufferedReader(new InputStreamReader(in)); 
      sb = new StringBuilder(); 
      while ((line = reader.readLine()) != null) 
       sb.append(line); 

      result = sb.toString(); 
      result = result.trim(); 
      result = result.substring(1, result.length()); 
      Log.i("RESULT", result); 
     } else 
      Log.e("Error", "" + statusCode); 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } finally { 
     try { 
      if (in != null) { 
       in.close(); 
       in = null; 
      } 

      httpPost = null; 
      httpClient = null; 
      httpResponse = null; 
      entity = null; 
      in = null; 
      reader = null; 
      sb = null; 
      line = null; 

     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    } 

    return result; 
} 

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

    System.out.println("Inside the afghan Read category"); 
    View view = (View) inflater.inflate(R.layout.categoryfragment, null); 
    list = (ListView) view.findViewById(R.id.cat_list); 

    /* 
    * ArrayAdapter<String> adapter = new 
    * ArrayAdapter<String>(getActivity(), 
    * android.R.layout.simple_list_item_1, values); 
    */ 
    parseJSON(); 
    list.setAdapter(new CustomAdapter(getActivity(), R.layout.categoryitem, 
      values)); 

    list.setOnItemClickListener(this); 
    return view; 
} 

@Override 
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) { 
    String item = (String) values[arg2]; 
    LibraryFragment fragment = (LibraryFragment) getFragmentManager() 
      .findFragmentById(R.id.library); 
    if (fragment != null && fragment.isInLayout()) { 
     fragment.setText(item); 
    } else { 
     Intent intent = new Intent(getActivity().getApplicationContext(), 
       LibraryActivity.class); 
     intent.putExtra("value", item); 
     startActivity(intent); 
    } 

} 

public class CustomAdapter extends BaseAdapter { 
    String names[]; 
    Context mCtx; 
    int item; 
    LayoutInflater inflater; 

    public CustomAdapter(Context ctx, int categoryitem, String[] values) { 

     this.names = values; 
     this.mCtx = ctx; 
     this.item = categoryitem; 
     inflater = (LayoutInflater) ctx 
       .getSystemService(getActivity().LAYOUT_INFLATER_SERVICE); 
    } 

    @Override 
    public int getCount() { 
     // TODO Auto-generated method stub 
     return names.length; 
    } 

    @Override 
    public Object getItem(int position) { 
     // TODO Auto-generated method stub 
     return null; 
    } 

    @Override 
    public long getItemId(int position) { 
     // TODO Auto-generated method stub 
     return 0; 
    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     if (convertView == null) { 

      convertView = inflater.inflate(item, null); 
      cat_name = (TextView) convertView.findViewById(R.id.cat_name); 

     } 

     cat_name.setText(names[position]); 

     return convertView; 

    } 

} 

}

如何解決這個問題？

Answer 1

我想網絡通話會失敗，您傳遞null給new JSONObject(getJSONData())。
是JSONObject jObject = new JSONObject（getJSONData（））;第72行，作爲logcat輸出中的空指針的原點聲明：com.afghanread.android.CategoryFragment.parseJSON（CategoryFragment.java:72）？

與錯誤不完全相關，但在代碼中也是一個大問題。你正在UI-Thread內部做一個webcall。這將凍結手機，直到從服務器上加載json數據。您至少應該將所有數據加載代碼放入AsyncTask，並在onPostExecute方法中更新您的UI。