- (id)performSelector:(SEL)aSelector;调用和直接调用区别

performSelector调用和直接调用区别

performSelector是运行时系统负责去找方法的,直接调用方法时候，一定要在头文件中声明该方法的使用，也要将头文件import进来。而使用performSelector时候，可以不用import头文件包含方法的对象，直接用performSelector调用即可。

- (id)performSelector:(SEL)aSelector;

- (id)performSelector:(SEL)aSelector withObject:(id)object;

- (id)performSelector:(SEL)aSelector withObject:(id)object1 withObject:(id)object2;
 //例  用performSelector方法调用domeName方法(同时赋值);

 [person performSelector:@selector(domeName:)
withObject:@"sdfg"];

 //延迟调用   

 [person performSelector:@selector(dome)
withObject:nil
afterDelay:5];

[[NSRunLoop currentRunLoop] run];----------让程序继续运行