Creating an instance of an interface itself in Android

Question

Here is code ``` btn.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { //... } }); ``` where `setOnClickListener` looks like: ``` public void setOnClickListener(android.view.View.OnClickListener l) { /* compiled code */ } ``` However, what's `new View.OnClickListener()` itself? It turns out this is an interface: ``` //View.class public static interface OnClickListener { void onClick(android.view.View view); } ``` That is, here `btn.setOnClickListener(new View.OnClickListener() ....` I create an instance of the interface. No, this is not the instance of a class which implements this interface. How is it possible to create an instance of an interface?

Accepted Answer

Yes, it is. It is a Anonymous class that implements the interface. The onclick that goes after is the implementation of onclick.

Try to do it like this:

```
View.OnClickListener listener=new View.OnClickListener() {
  public void onClick(View v) {
    //...
  }
};
btn.setOnClickListener(listener);
```

This may look more clear.

Creating an instance of an interface itself in Android

Solution

Problem