What does "this" mean for ViewPagers?

Question

I am making a page listener, I've seen a view people do this:

ViewPager.addOnPageChangeListener(this);

What does that mean? What does that code even do, seems like nothing? I thought "this" meant the current Activity or context but I feel like the above code is not doing anything.

The current instance of the class you're in. In this context, the class you're in should be implementing the OnPageChangeListener interface. — Ryan, Jan 31 '22 at 22:26
Does this answer your question? [What is the meaning of "this" in Java?](https://stackoverflow.com/questions/3728062/what-is-the-meaning-of-this-in-java) — cmak, Jan 31 '22 at 23:10

score 1 · Accepted Answer · edited Feb 11 '22 at 14:21

1

It means it is referring to a onPageChangeListner object which u need to create sepearately. So you will have to create a OnPageChangeListener like this:

ViewPager.OnPageChangeListener()  pageChangeListener = new ViewPager.OnPageChangeListener() {}

And then use it like:

ViewPager.addOnPageChangeListener(this)

So basically this means the reference of the onPageChangeListener object

edited Feb 11 '22 at 14:21

YourHelper

703
7
17

answered Feb 10 '22 at 17:25

Ruchi

71
3

Thank you! This answer makes sense! – Android Dev Feb 14 '22 at 18:43

What does "this" mean for ViewPagers?

1 Answers1