【iOS学习笔记】Objective-C中根据函数名调用函数

原文出自：http://blog.csdn.net/hopedark/article/details/7970370

 

Objective-C中调用函数的方法是“消息传递”，这个和普通的函数调用的区别是，你可以随时对一个对象传递任何消息，而不需要在编译的时候声明这些方法。所以Objective-C可以在runtime的时候传递消息。

主要用到：SEL和@selector，当然还有performSelector

看例子：

先是三个函数：

 

[cpp]  view plain copy -(void)CallBack0  {      NSLog(@"CallBack0");  }    -(void)CallBack1:(int)a  {      NSLog(@"CallBack1:a=%i",a);  }    -(void)CallBack2:(int)a b:(int)b  {      NSLog(@"CallBack2:a=%i,b=%i",a,b);  }  

performSelector调用：

 

 

[cpp]  view plain copy [self performSelector:@selector(CallBack0)];  [self performSelector:@selector(CallBack1:) withObject:1];  [self performSelector:@selector(CallBack2:b:) withObject:1 withObject:2];  

 

 

根据函数名动态调用：

 

[cpp]  view plain copy NSString *a=@"CallBack0";  SEL faSelector=NSSelectorFromString(a);  [self performSelector:faSelector];        NSString *b=@"CallBack1:";  SEL fbSelector=NSSelectorFromString(b);  [self performSelector:fbSelector withObject:1];        NSString *c=@"CallBack2:b:";  SEL fcSelector=NSSelectorFromString(c);  [self performSelector:fcSelector withObject:1 withObject:2];  

这样就可以根据函数名调用函数啦！

转载于:https://www.cnblogs.com/pjl0426/p/5015119.html