的活动Android系统服务不（）

Question

....  

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

    ... 

done = true; 
} 

... 


public class addcontacts extends ListActivity { 

    protected void onCreate() { 

    } 
    protected void execute(final Boolean success) { 
if (done) { 
     adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, listItems); 
     setListAdapter(adapter); 
} 
    } 

} 


public class UserLoginTask extends AsyncTask<Void, Void, Boolean> { 

@Override 
    protected Boolean doInBackground(Void... params) { 

... 

} 
@Override 
    protected void onPostExecute(final Boolean success) { 

      setContentView(R.layout.main); 


      ac = new addcontacts(); 
      ac.execute(true); 


    } 

... 

public class getcontacts extends AsyncTask<Void, Void, Boolean> { 
    @Override 
    protected Boolean doInBackground(Void... params) { 


... 
listItems.add(json_data.getString("login") + " " + derp); 
... 
} 

... 
} 

@Override 
    protected void onPostExecute(final Boolean success) { 
     getc = null; 
     //showProgress(false); 
     adapter.notifyDataSetChanged(); 
} 

运行时错误：

02-12 15:59:35.274: E/AndroidRuntime(1308): FATAL EXCEPTION: main 
02-12 15:59:35.274: E/AndroidRuntime(1308): java.lang.IllegalStateException: System services not available to Activities before onCreate() 
02-12 15:59:35.274: E/AndroidRuntime(1308): at android.app.Activity.getSystemService(Activity.java:3989) 

02-12 15:59:35.274: E/AndroidRuntime(1308): at android.widget.ArrayAdapter.init(ArrayAdapter.java:310) 
02-12 15:59:35.274: E/AndroidRuntime(1308): at android.widget.ArrayAdapter.<init>(ArrayAdapter.java:153) 

任何想法如何解决呢？

Answer 1

唯一被破坏的是你的代码。修复是为了避免在onCreate（）完成之前访问系统服务，否则没有对活动对象进行设置，因此是您所面临的自我解释的原因异常。