CODEWITHSUNDEEP
javaandroidandroid-layout
NewProger
NewProger

Reputation: 3075

Accessing UI elements in Activity from another class

I have a problem with that code

setContentView(R.layout.game);
TextView text = (TextView) findViewById(R.id.qwe_string);
text.setText("Hello Android");

It works if it's inside an activity, but if it isn't, obviously, it gives errors:

The method findViewById(int) is undefined for the type new TimerTask(){}
The method setContentView(int) is undefined for the type new TimerTask(){}

The code is inside a timer in separate class (not activity). The full code is as follows.

//main timer task for ingame time processing
static Timer gameTimer = new Timer();
static TimerTask gameTimerTask = new TimerTask() {
    @Override
    public void run() {
        setContentView(R.layout.game);
        TextView text = (TextView) findViewById(R.id.qwe_string);
        text.setText("Hello Android");
    }
};

I tried changing it like that

ScreenGame.this.setContentView(R.layout.game);
TextView text = (TextView) ScreenGame.this.findViewById(R.id.qwe_string);
text.setText("Hello Android");

But it still doesn't work :(

PS - Yes, I searched other similar questions, but all of them although appear to be the same, in fact completely different.

Upvotes: 2

Views: 4660

Answers (2)

Hidde
Hidde

Reputation: 11931

ScreenGame.this.setContentView(R.layout.game);
TextView text = (TextView) ScreenGame.this.findViewById(R.id.qwe_string);
text.setText("Hello Android");

is exactly the same as

setContentView(R.layout.game);
TextView text = (TextView) findViewById(R.id.qwe_string);
text.setText("Hello Android");

wrong code

You should make a parent class, that fires off all the other Activities. In that parent class, you can have a reference to each child activity, and you can ask each child for it's textfield: 

// In the parent:
child.getTextView().setText("Hello galaxy!");

// with the child method:
TextView getTextView () {
  return (TextView) findViewById(R.id.qwe_string);
}

EDIT: More info:

The code I gave was not good, I hadn't understood your problem well... I hope I do now, do I'll try to correct myself.

Make a seperate class, for example MyTimer, which will extends the TimerTask class:

class MyTimer extends TimerTask {
  // your class
}

Make a constructor, that excepts an TextView as an argument, and saves a reference to it.

TextView theTextView;
MyTimer (TextView tv) {
  this.theTextView = tv;
}

Now implement run():

@Override
public void run() {
    setContentView(R.layout.game);
    thetextView.setText("Hello Galaxy!");
}

Call make this class using the following code:

static TimerTask gameTimerTask = new MyTimer((TextView) findViewById(R.id.qwe_string));

I hope this is all correct, I have to do this from memory as I don't have any testing environment. At least it should help you in the right direction.

Upvotes: 2

Hakan Serce
Hakan Serce

Reputation: 11256

You will need:

ScreenGame.this.runOnUiThread( new Runnable(){
  public void run(){
   TextView text = (TextView) ScreenGame.this.findViewById(R.id.qwe_string);
   text.setText("Hello Android");  }
 });

And you should call the following line in onCreate() of ScreenGame:

setContentView(R.layout.game);

Upvotes: 0

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