Question

I have a layout in xml.

In my activity, in the onCreate method i get a reference to the view i want to update periodically like this:

TextView myText = (TextView)findViewById(R.id.textview1);

Then, in a periodic method, i do this:

myText.setText(Float.toString(myData));

It works fine, until the screen rotates.

I read that when the screen rotates, the layout is recreated, and all the views on the layout are recreated, so the old references don’t work.

My code:

private TextView myText; //Its a class member

public void onCreate(Bundle savedInstanceState) {
   //Other things
   myText = (TextView)findViewById(R.id.textview1);
   //Other things
}

//This is the periodic method, it occurs many times per second
public final void onSensorChanged(SensorEvent event) {
   myText.setText(Float.toString(event.myData)); 
   //This setText works fine until the screen rotation
}

How can i have a permanent reference to the view?
And how can i know when the screen has rotated?

Thanx

Answer 1

You might be thinking about things a little incorrectly if you want a permanent reference. The view is removed from memory when the phone is rotated (assuming you allow rotation.)

At the point of rotation you will need to get a pointer to the newly created object.

To detect orientation changes related to layout use onConfigurationChanged as shown in this post.

How to detect orientation change in layout in Android?