objective-c - Objective-C : where to declare private instance properties?

Question

我有以下类接口(interface):

@interface MyClass : NSObject

@property int publicProperty;

@end

然后是实现:

@interface MyClass() // class extension

- (void)privateMethod; // private methods

@end

@implementation MyClass {
    int _privateProperty;
}

@property int privateProperty = _privateProperty;

@end

这是 Apple 人在 WWDC 上展示的内容，但是有什么理由不将 _privateProperty 放在类扩展中，例如:

@interface MyClass() // class extension
{
    int _privateProperty;
}

- (void)privateMethod; // private methods

@end

谢谢!

Answer 1

我通常在实现中通过扩展“强制”私有(private)

在你的标题中

@interface MyClass : NSObject
{
}

@property (nonatomic, assign) int publicProperty;

@end

在你的实现文件中:

@interface MyClass ()
@property (nonatomic, assign) int privateProperty;
@end


@implementation MyClass
@synthesize privateProperty;
@synthesize publicProperty;

@end