android Avoid Memory Leaks 内部类问题

An inner class holds a reference to the object instance that created it; 

thus, in the following: 

public class Outer 

{ 

  public class Inner 

  { 

  } 

  Inner i = new Inner(); 

} 

Outer o = new Outer; 

Outer.Inner oi = o.i; 

o = null; 

  // o is still alive because oi references it 

oii has a hidden reference (the "outer this") to the enclosing class 

instance o. So long as somebody holds a reference to the Inner object, the 

reference to the outer object remains alive. 

If you mark the enclosing class or enclosing method as static, the inner 

class will be a static inner class, which holds no reference to the 

enclosing class (and also therefore lacks the ability to referencere fields 

and methods of the outer class). 

Event listeners were a common source of leaks (meaning, longer-lived objects 

than intended) in Swing code back in the day. Might try hunting around that 

way on Google--there used to be a great article on "four types of lapsed 

listeners" back then, that described all of this in more detail.