这样写有什么好处?
class A
{
static class B implements Icon // (1)
{
static class State // (2)
{
public static final State Normal = new State(); //(3)
public static final State Pressed = new State();
public static final State Rollover = new State();
private State();
}
State state;
public B( State state )
{
this.state = state;
}
}
}
问题:
A : (1) 和 (2) 这里为什么要申明为static类,是因为(3)这里吗?
B : 我看它实现class State 为的就是标识状态,为什么要写得这么累,这样
写有什么好处?