Question

I am having trouble figuring out how this is done in android. It is a very simple application, a TextView taking up the majority of the screen and a ToggleButton on the bottom. When the button is toggled on the phone communicates over a socket every 5 seconds requesting new data, this new data must then be prepended to the top of the TextView.

Because you don’t want to do the 5 second timers or the network activity in the main thread I’ve been using asynctask but threads outside the main thread can’t update the TextView.

Here is some pseudocode for what I am doing. How can I make it so updateView is called each time new data is received, but from the main thread?

Communication(IO) Variables

LinkedList of strings for TextView

public class MyActivity {
//setContentView
//setup network connection
//getTextView 
//getToggleButton
    //when clicked on start asynctask GetData
    //when clicked off stop GetData (set global boolean to false)
}

public void updateView(){

//take linked list and make one String of proper size for textview
//setTextView

}

private class GetData extends AsyncTask {

//while we want to get data (global boolean variable)
    //send request
    //wait for response
    //*update global text variable for the view* 
    //sleep for 5 seconds

}

Answer 1

You can do this inside your AsyncTask in onPostExecute() or in onProgressUpdate()method. From there you can trigger updates on the UI. I assume that in doInBackground() you fetch the data.