Android异常：错误膨胀类片段

Question

我是Android的新手。我正在研究一个小的Android应用程序，用于学习新的概念。

我正在fragments上工作。我在进行HTTP请求时卡住了。我正在使用HttpUrlConnection库来完成我的任务。

我已经创建了下面的代码至今：

MainActivity.java：

public class MainActivity extends AppCompatActivity { 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
    setSupportActionBar(toolbar); 

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); 
    fab.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) 
        .setAction("Action", null).show(); 
     } 
    }); 
} 

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

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle action bar item clicks here. The action bar will 
    // automatically handle clicks on the Home/Up button, so long 
    // as you specify a parent activity in AndroidManifest.xml. 
    int id = item.getItemId(); 

    //noinspection SimplifiableIfStatement 
    if (id == R.id.action_settings) { 
     return true; 
    } 

    return super.onOptionsItemSelected(item); 

} 
} 

MainActivityFragment.java

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

    HttpURLConnection urlConnection = null; 
    BufferedReader reader = null; 
    InputStream in = null; 
    String forecastJsonStr = null; 
    int resCode = -1; 

    try { 

     URL url= new URL("http://api.openweathermap.org/data/2.5/forecast/daily?q=94043&mode=json&units=metric&cnt=7&APPID=XXX"); 

     urlConnection= (HttpURLConnection) url.openConnection(); 
     urlConnection.setRequestMethod("GET"); 
     urlConnection.connect(); 

     resCode=urlConnection.getResponseCode(); 

     if(resCode == HttpURLConnection.HTTP_OK){ 

      in = urlConnection.getInputStream(); 
     } 

     reader = new BufferedReader(new InputStreamReader(in)); 

     StringBuffer buffer = new StringBuffer(); 
     String line; 
     while ((line = reader.readLine()) != null) { 

      buffer.append(line + "\n"); 
     } 

     if (buffer.length() == 0) { 
      return null; 
     } 
     forecastJsonStr = buffer.toString(); 

     Log.d("responce", forecastJsonStr); 
    } 

    catch (IOException e1) { 
     e1.printStackTrace(); 
    } 

//You can ignore the lower portion of the code. I have just created an arraylist of weather and am showing on the android app 

    String[] data={"Mon 6/23 - Sunny - 31/17", 
      "Tue 6/24 - Foggy - 21/8", 
      "Wed 6/25 - Cloudy - 22/17", 
      "Thurs 6/26 - Rainy - 18/11", 
      "Fri 6/27 - Foggy - 21/10", 
      "Sat 6/28 - TRAPPED IN WEATHERSTATION - 23/18", 
      "Sun 6/29 - Sunny - 20/7"}; 

    List<String> weekForcast = new ArrayList<String>(Arrays.asList(data)); 

    ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(getActivity(), R.layout.list_item_forecast, R.id.list_item_forecast_textview,weekForcast); 

    View rootView = inflater.inflate(R.layout.fragment_main,container,false); 
    ListView listView = (ListView) rootView.findViewById(R.id.listview_forcast); 
    listView.setAdapter(arrayAdapter); 
    return rootView; 
} 

每当我试图运行的代码，我得到以下错误：

> Process: com.example.android.udacityclass, PID: 20766 02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity 
> ComponentInfo{com.example.android.udacityclass/com.example.android.udacityclass.MainActivity}: 
> android.view.InflateException: Binary XML file line #1: Error 
> inflating class fragment 02-05 16:54:20.695 
> 20766-20766/com.example.android.udacityclass E/AndroidRuntime:  at 
> android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2358) 
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2420) 
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.app.ActivityThread.access$900(ActivityThread.java:154) 02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321) 
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.os.Handler.dispatchMessage(Handler.java:102) 02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at android.os.Looper.loop(Looper.java:135) 02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.app.ActivityThread.main(ActivityThread.java:5292) 02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at java.lang.reflect.Method.invoke(Native 
> Method) 02-05 16:54:20.695 
> 20766-20766/com.example.android.udacityclass E/AndroidRuntime:  at 
> java.lang.reflect.Method.invoke(Method.java:372) 02-05 16:54:20.695 
> 20766-20766/com.example.android.udacityclass E/AndroidRuntime:  at 
> com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904) 
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699) 02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime: Caused by: android.view.InflateException: Binary 
> XML file line #1: Error inflating class fragment 02-05 16:54:20.695 
> 20766-20766/com.example.android.udacityclass E/AndroidRuntime:  at 
> android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:763) 
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.view.LayoutInflater.parseInclude(LayoutInflater.java:892) 
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.view.LayoutInflater.rInflate(LayoutInflater.java:802) 02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.view.LayoutInflater.inflate(LayoutInflater.java:504) 02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.view.LayoutInflater.inflate(LayoutInflater.java:414) 02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.view.LayoutInflater.inflate(LayoutInflater.java:365) 02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:257) 
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109) 
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> com.example.android.udacityclass.MainActivity.onCreate(MainActivity.java:17) 
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.app.Activity.performCreate(Activity.java:5990) 02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106) 
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2311) 
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2420)  
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.app.ActivityThread.access$900(ActivityThread.java:154)  02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321)  
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.os.Handler.dispatchMessage(Handler.java:102)  02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at android.os.Looper.loop(Looper.java:135)  
> 02-05 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at 
> android.app.ActivityThread.main(ActivityThread.java:5292)  02-05 
> 16:54:20.695 20766-20766/com.example.android.udacityclass 
> E/AndroidRuntime:  at java.lang.reflect.Method.invoke(Native 
> Method)  02-05 16:54:20.695 
> 20766-20766/com.example.android.udacityclass E/AndroidRuntime:  at 
> java.lang.reflect.Method.invoke(Method.java:372) 

任何人都可以帮助我解决这个错误。此外，有人可以帮助我找到在android中调试错误的参考。非常感谢

Answer 1

看起来您正在主线程上发出请求，请使用Asynctask <>在后台线程中发出请求。看看这个链接如何使用，在doInbackground方法中创建你的http请求。

http://programmerguru.com/android-tutorial/android-asynctask-example/

在Android背景的进一步细节处理结账这个环节 http://www.vogella.com/tutorials/AndroidBackgroundProcessing/article.html 希望这有助于。