CODEWITHSUNDEEP
androidandroid-asynctask
GMX
GMX

Reputation: 960

Get a TextView in an AsyncTask - Android

I want to publish the result of my AsyncTask (a string) in a textView.

Here is my Main:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    ReadRss readRss=new ReadRss(this);
    readRss.execute();
    ......
}

Here is my AsyncTask:

public class ReadRss extends AsyncTask<Void,Void,Void> {

public ReadRss(Context context){
}

@Override
protected void onPreExecute() {
}

@Override
protected void onPostExecute(Void aVoid) {
}

@Override
protected Void doInBackground(Void... params) {
    ProcessXml();
    return null;
}

private void ProcessXml() {
    //HERE CREATE MY STRING
    String myresult="example";

    TextView txt_ris = (TextView)findViewById(R.id.txt_ris);  <---HOW CAN I DO THIS?
    txt_ris.setText(myresult);   

            }

        }
    }
}

FindViewById don't work in the AsyncTask so how can i get the TextView in here? Maybe i can pass it as a paramiter in the AsyncTask, What is the syntax?

Upvotes: 1

Views: 598

Answers (2)

Mikhail Spitsin
Mikhail Spitsin

Reputation: 2608

You need to place UI work in onPostExecute method, since doInBackground executes in not UI thread

public class ReadRss extends AsyncTask<Void,Void,String> {

    public ReadRss(Context context){
    }

    @Override
    protected void onPreExecute() {
    }

    @Override
    protected void onPostExecute(String string) {
        TextView txt_ris = (TextView)findViewById(R.id.txt_ris);
        txt_ris.setText(myresult); 
    }

    @Override
    protected String doInBackground(Void... params) {
        return ProcessXml();
    }

    private String ProcessXml() {
        //HERE CREATE MY STRING
        return "example";
    }
}

Upvotes: 2

Chisko
Chisko

Reputation: 3107

For your TextView to be correctly referenced you need a context and you already have a reference to your starting Activity in your AsyncTask constructor, so you can do something like:

public class ReadRss extends AsyncTask<Void,Void,Void> {

     private TextView tv;
     private YourStartingActivity activity;

     public ReadRss(Context context){
         activity = (YourStartingActivity)context;
         tv = (TextView)activity.findViewById(R.id.txt_ris)
     }

     @Override
     protected void onPreExecute() {
         ...
     }

     @Override
     protected void onPostExecute(Void aVoid) {
         (follow Michael Spitsin instructions here)
     }

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

Upvotes: 1

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