Can not access “findViewById” in AsyncTask

Question

https://stackoverflow.com/a/14164318/3575963

Here, he used

View myFragmentView = inflater.inflate(R.layout.fragment_a, container, false);

From parent class. Also I don't have inflater in my parent, it is a map.

And from asynctask doitbackground, I returned 5 arraylists to make textview in postexecute.

But I can't do because I can't use findviewbyid because I can't get activity. I got context but it does not do anything.

Here is my postexecute

  protected void onPostExecute(Wrapper wrap){

     TextView name = new TextView (mContext);
     TextView type = new TextView (mContext);
     TextView location = new TextView (mContext);
     TextView distance = new TextView (mContext);

     List<Double> dist = new ArrayList();
     List<String> loc = new ArrayList();
     List<String> nme = new ArrayList();
     List<String> typ = new ArrayList();
     List<Calendar> start = new ArrayList();
     List<Calendar> endd = new ArrayList();

     dist = wrap.getDist();
     loc = wrap.getLocation();
     nme = wrap.getName();
     typ = wrap.getType();
     start = wrap.getsDate();
     endd = wrap.geteDate();
     int idx = -1;
     LinearLayout shw_evnt = (LinearLayout) shw_evnt.findViewById(R.id.);

      for(Double dis:dist){
         idx++;
         name.setText(nme.get(idx));
         type.setText(typ.get(idx));
         location.setText(loc.get(idx));
         distance.setText(dist.get(idx).toString()+" meters");

This part is faulty

 LinearLayout shw_evnt = (LinearLayout) shw_evnt.findViewById(R.id.);

I tried other things but it did not work. I will use another layout that was not used before.

show_events.xml:

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

</LinearLayout>

Here caller mapactivity class

 public class MapActivity extends AppCompatActivity  implements GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener {
    private int strokeColor = 0xffff0000; //red outline
    private int shadeColor = 0x44ff0000; //opaque red fill
    private int count=0;
    private GoogleMap googleMap;
    private GoogleApiClient mGoogleApiClient;
    private Location mLastLocation;
    private LocationRequest mLocationRequest;
    private Context mContext;
    private String TAG = "Chic";
    private final static int CONNECTION_FAILURE_RESOLUTION_REQUEST = 9000;
    private int radius;//in meters
    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    protected void onCreate(Bundle savedInstanceState) {
        Log.d(TAG, "inside map oncreaste");
        mContext =  getApplicationContext();
        View myFragmentView = inflater.inflate(R.layout.show_events, container, false);
        super.onCreate(savedInstanceState);
        setUpMapIfNeeded();
        Log.d(TAG, "buildgoogleapi called");
        buildGoogleApiClient();
        Log.d(TAG, "after buildgoogleapi called");
     }//end of oncreate

here error on that

View myFragmentView = inflater.inflate(R.layout.show_events, container, false);

because i dont have inflater

I dont want to return from postexecute to main class or another wrapper class. I think i can do inside postexecute, cant i?

LayoutInflater inflater = (LayoutInflater)context.getSystemService
  (Context.LAYOUT_INFLATER_SERVICE);

if i do this, i will take current view, not the view i want to create?

I tried

private Inflater inflater;
     View myFragmentView = inflater.inflate(R.layout.show_events, container, false);

Answer 1

Yep, just pass the Activity to the Asynctask:

   AsyncTask myAsyncTask = new MyTask(this);

And then you will find the element inside the layout of the Activity:

public class MyTask extends AsyncTask<String, String, String>{
    public MyActivity activity;

    public MyTask(MyActivity a){
        this.activity = a;
    }
    protected void onPostExecute(String result){
...
...
       LinearLayout shw_evnt = (LinearLayout) activity.findViewById(R.id.shwevnt);
...
...
    }
}

Like Daniel describes it would be a bad practice.

I recommend to you an Interface.

for example:

a) Create interface class.

public interface AsyncResponse {
    void processFinish(String output);
}

b) Go to your AsyncTask class, and declare interface AsyncResponse as a field :

public class MyAsyncTask extends AsyncTask{
    public AsyncResponse delegate = null;
    @Override
    protected void onPostExecute(String result) {
         delegate.processFinish(result);
    }
}

c) In your main Activity you need to implements interface AsyncResponse.

public class MainActivity implements AsyncResponse{    
MyAsyncTask asyncTask =new MyAsyncTask();
      @Override
      public void onCreate(Bundle savedInstanceState) {
         //this to set delegate/listener back to this class
         asyncTask.delegate = this;
    
         //execute the async task 
         asyncTask.execute();
      }
      //this override the implemented method from asyncTask
      void processFinish(String output){
         //Here you will receive the result fired from async class 
         //of onPostExecute(result) method.
           LinearLayout shw_evnt = (LinearLayout) findViewById(R.id.shwevnt);
       }
     }

Answer 2

this is the solution..

facturas_edittext=(EditText)((Activity)context).findViewById(R.id.mye);

Answer 3

Just pass the Activity as a parameter to the AsyncTask class. See here. Note that its bad practice to store context as a member variable since the context may change.