无法解析符号'适配器'

Question

我收到以下代码的错误。我不明白为什么，但adapter.notifyDataSetChanged();不起作用。错误消息是：“无法解析符号'适配器'”。

final String URL = "http://example...."; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 

    rv = (RecyclerView) findViewById(R.id.rv); 

    .... 

    public class PrintA extends AsyncTask<String, String, List<Model>> { 
     .... 
     @Override 
     protected void onPostExecute(final List<MyModel> result) { 
      super.onPostExecute(result); 
      if (result != null) { 
       MyAdapter adapter = new MyAdapter(result); 
       rv.setAdapter(adapter); 
      } else { 
       Toast.makeText(getApplicationContext(), "no internet",     
      } 
     } 
    } 

    new PrintA().execute(URL); 

    rv.addOnScrollListener(new RecyclerView.OnScrollListener() { 
     .... 
     public class PrintB extends AsyncTask<String, String, List<Model>> { 
      .... 

      @Override 
      protected void onPostExecute(final List<MyModel> result) { 
       super.onPostExecute(result); 
       if (result != null) { 
        .... 
        adapter.notifyDataSetChanged(); 
       } else { 
        Toast.makeText(getApplicationContext(), "can't add",     
       } 
      } 

      @Override 
      public void onScrolled(RecyclerView recyclerView, int dx, int dy) { 
       ....    
       new PrintB().execute(URL); 
      } 
     } 
    } 
} 

Answer 1

MyAdapter adapter = new MyAdapter(result); 

通过

adapter = new MyAdapter(result); 

代替这一点，并声明此全球

MyAdapter adapter; 

这样

MyAdapter adapter; 

@Override 
protected void onCreate(Bundle savedInstanceState) {