<<^ 随机颜色>>

创建一个延展类, 声明一个外界可以访问的方法, 然后在.m文件实现该方法.

#import "UIColor+RandomColor.h"

@implementation UIColor (RandomColor)

+(UIColor *)randomColor{
    
    return [UIColor colorWithRed:arc4random()%256/255.0 green:arc4random()%256/255.0 blue:arc4random()%256/255.0 alpha:1];
}
@end```