Change TextView value using uithread

Question

I'm trying to change some textview value but when it's not appeared on the screen the value don't change or when it's appeared on screen it changes and when scroll down and scroll back up it's value returns to the old one i tried the following two ways but non of them is working :

final Timer timer=new Timer();
timer.schedule(new TimerTask() {
    @Override
    public void run() {
        MainActivity.this.runOnUiThread(new Runnable() {
            @Override
            public void run() {
                myTextView.setText("sometext");
                timer.cancel();
            }
        });
    }
}, 5000, 1000);

and:

MainActivity.this.r1.post(new Runnable() {
    public void run() {
        myTextView.setText("sometext");
    }
});

Try removing timer.cancel() as it is forcing the timer to execute just once. — Parag Kadam, Aug 26 '15 at 14:03
it takes high usage of the memory and causes too much work on the main thread , my question is about updating text view after id generation once — Waleed Saad Jebreen, Aug 26 '15 at 14:24
Solved it or shall I update my answer? you have to mark a question as a correct — Skizo-ozᴉʞS ツ, Sep 22 '15 at 21:11

score 0 · Answer 1 · answered Aug 26 '15 at 13:55

Try using Handler

    private void TestThread() {
    Handler handler = new Handler();
    Runnable runnable = new Runnable() {
        public void run() {
                 handler.post(new Runnable(){
                    public void run() {
                       tvTime.setText("SomeText");
                    }
                 });
        }
    }
    };
    new Thread(runnable).start();
}

Also you can take a look AsyncTask Documentation and onPostExecute() you set the text to TextView.

score 0 · Answer 2 · answered Aug 26 '15 at 14:33

0

You have to make sure that the UI is drawn first before you change the value of the TextView , It can be done by adding a layout listener,

ViewTreeObserver vto = getWindow().getDecorView().getViewTreeObserver();
vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Overrid
public void onGlobalLayout() {
final Timer timer=new Timer();
timer.schedule(new TimerTask() {
    @Override
    public void run() {
        MainActivity.this.runOnUiThread(new Runnable() {
            @Override
            public void run() {
                myTextView.setText("sometext");
                timer.cancel();
            }
        });
    }
}, 5000, 1000);
}
}

answered Aug 26 '15 at 14:33

Parag Kadam

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OnGlobalLayoutListener keeps calling it self , and thats not what i wanted , i need to change all textviews one time even the not shown ones , because of the CPU usage !?!?!?!?!?!? – Waleed Saad Jebreen Aug 27 '15 at 13:58
your answer is great but it makes the CPU do too much work :) – Waleed Saad Jebreen Aug 27 '15 at 14:00
The OnGlobalLayoutListener is called only when the layout is drawn ,how is it calling itself again and again? – Parag Kadam Aug 28 '15 at 06:36
So you mean that it is working for you just that it is too hard on the CPU? – Parag Kadam Aug 28 '15 at 06:37

Change TextView value using uithread

2 Answers2