记录个随机背景颜色的方法:
+ (UIColor*) randomColor{ NSInteger r = arc4random() % 255; NSInteger g = arc4random() % 255; NSInteger b = arc4random() % 255; return [UIColor colorWithRed:r/255.0 green:g/255.0 blue:b/255.0 alpha:1]; }
类方法,仅做记录!