Obj-C @synthesize

Question

  

可能重复：
  Prefixing property names with an underscore in Objective C

iPhone App Developer初学者：

in .h

@property (nonatomic, retain) IBOutlet UILabel *detailDescriptionLabel;

in .m

@synthesize detailDescriptionLabel = _detailDescriptionLabel;

我习惯看

@synthesize detailDescriptionLabel;

= _让我失望，这是做什么的？

Answer 1

每个属性都由实例变量支持。该语言允许以不同的方式命名它们。通过执行@synthesize detailDescriptionLabel = _detailDescriptionLabel;，您基本上会说使用_detailDescriptionLabel作为属性detailDescriptionLabel的支持实例变量。如果您只是@synthesize detailDescriptionLabel;，它会隐含地理解实例变量具有相同的名称。

Answer 2

n .h

    UILabel *_detailDescriptionLabel;
}
    @property (strong, nonatomic) IBOutlet UILabel *detailDescriptionLabel;

in .m

@synthesize detailDescriptionLabel = _detailDescriptionLabel;

此行表示属性“detailDescriptionLabel”将具有名为“_detailDescriptionLabel”的类属性的setter和getter

如果名称相同，您将拥有

@synthesize detailDescriptionLabel;