框架设计

1.NS_DESIGNATED_INITIALIZER

• 方法后面带有 NS_DESIGNATED_INITIALIZER 时, 为特定构造方法
• 注意:子类如果重写了父类的特定构造方法, 那么必须使用super调用父类的特定构造方法
• 警告信息:
• Designated initializer missing a ‘super‘ call to a designated initializer of the super class
• 例子

  - (instancetype)initWithFrame:(CGRect)frame
  {
      if (self = [super initWithFrame:frame]) {
          self.titleLabel.font = [UIFont systemFontOfSize:16];
          // 文字颜色
          [self setTitleColor:[UIColor darkGrayColor] forState:UIControlStateNormal];
          [self setTitleColor:[UIColor redColor] forState:UIControlStateSelected];
      }
      return self;
  }

2.NS_REQUIRES_SUPER

• 方法后面带有 NS_REQUIRES_SUPER , 则必须先调用父类的方法
• 警告信息:
• Method possibly missing a [super run] call

@interface XMGTest : NSObject
- (void)run NS_REQUIRES_SUPER;
@end

@interface XMGSecondTest : XMGTest
@end
@implementation XMGSecondTest
- (void)run
{
    // 不调用, 则会有警告信信
    //[super run];
}
@end