objective-c - Typedef 枚举 Objective-C

Question

我有 Distance 类和 typedef enum Unit，

@interface Distance:NSObject{

double m_miles;

}

@property double m_miles;

-(Distance *) initWithDistance: (double) value andUnit:(Unit) unit;

@implementation Distance

-(Distance *)initWithDistance: (double) value andUnit:(Unit) unit{

  self = [super init];

 if (self){

   switch (unit) {

     case Unit.miles:  m_miles = value;

                       break;

    case Unit.km:      m_miles = value/1.609344;

                       break;
}


}

我在哪里声明我的枚举单位？如何访问

typedef enum{

    miles;

    km;

}Unit

在另一个类中，我应该可以调用 Distance.Unit.km 或英里:

Distance *a = [[Distance alloc] initWithDistance: 10.2 andUnit: Distance.Unit.km];

Answer 1

在 C 中，enum 不会使其值“合格”。你必须访问它

Distance *a = [[Distance alloc] initWithDistance: 10.2 andUnit:km];
//                                                             ^^
//                                                             no Distance.Unit.stuff