objective-c - 如何在 Objective-C 中使用这个枚举？

Question

1) 我从此转换了这个 Swift 枚举:

public enum TimeZone {
    case Local, UTC
}

进入此:

@interface DateFormat : NSObject

@property enum TimeZone {Local, UTC};


+ (instancetype) ISODateFormat: (NSString *) isoFormat;
+ (instancetype) DotNetDateFormat;
+ (instancetype) RSSDateFormat;
+ (instancetype) AltRSSDateFormat;
+ (instancetype) CustomDateFormat: (NSString *) formatString;

@property (readonly) NSString *dateFormatType;
@property (readonly) NSString *formatDetails;


@end

<小时/>

2)现在我需要转换它:

func toString(format format: DateFormat, timeZone: TimeZone = .Local) -> String
{
    var dateFormat: String
    let zone: NSTimeZone

    switch format {

        case .DotNet:
            let offset = NSTimeZone.defaultTimeZone().secondsFromGMT / 3600
            let nowMillis = 1000 * self.timeIntervalSince1970
            return  "/Date(\(nowMillis)\(offset))/"

        case .ISO8601(let isoFormat):
            dateFormat = (isoFormat != nil) ? isoFormat!.rawValue : ISO8601Format.DateTimeMilliSec.rawValue
            zone = NSTimeZone.localTimeZone()

        case .RSS:
            dateFormat = RSSFormat
            zone = NSTimeZone.localTimeZone()

        case .AltRSS:
            dateFormat = AltRSSFormat
            zone = NSTimeZone.localTimeZone()

        case .Custom(let string):

            switch timeZone {
                case .Local:
                    zone = NSTimeZone.localTimeZone()
                case .UTC:
                    zone = NSTimeZone(forSecondsFromGMT: 0)
            }
            dateFormat = string
    }

    let formatter = NSDate.formatter(format: dateFormat, timeZone: zone)
    return formatter.stringFromDate(self)
}

<小时/>

3)这是我到目前为止转换的内容:

    - (NSString *) toString: (DateFormat *) format : (DateFormat *) timeZone{
        NSString *dateFormat;
        NSTimeZone *zone;
        if([format.dateFormatType compare: DotNetDateFormatType] == NSOrderedSame) {
            NSInteger offset = [[NSTimeZone defaultTimeZone] secondsFromGMT] / 3600;
            NSInteger nowMillis = 1000 * self.timeIntervalSince1970;
            return [NSString stringWithFormat:@"/Date(%ld%ld)/", (long)nowMillis, (long)offset];
        }
        else if([format.dateFormatType compare: ISO8601DateFormatType] == NSOrderedSame) {
            NSString *isoFormat = ISO8601DateFormatType;
            dateFormat =  (isoFormat != nil) ? isoFormat : ISOFormatDateTimeMilliSec;
        }
        else if([format.dateFormatType compare: RSSDateFormatType] == NSOrderedSame) {
            dateFormat = RSSDateFormatType;
        }
        else if([format.dateFormatType compare: AltRSSDateFormatType] == NSOrderedSame) {
            dateFormat = AltRSSDateFormatType;
        }
        else if([format.dateFormatType compare: CustomDateFormatType] == NSOrderedSame) {
            NSString *string = CustomDateFormatType;
            dateFormat = string;
        }
        NSDateFormatter *formatter = [NSDate formatter : dateFormat : [NSTimeZone localTimeZone] : [NSLocale currentLocale]];
        return [formatter stringFromDate:(self)];
    }

<小时/>

问题:

我在其中包含 TimeZone 枚举时遇到问题。我转换的所有行为都工作正常，我只需要实现枚举。有什么想法吗？

Answer 1

而不是内联enum声明:

@property enum TimeZone {Local, UTC};

在@interface之外将其声明为

typedef NS_ENUM(NSInteger, TimeZone) {
   kTimeZoneLocal = 0,
   kTimeZoneUTC
};

(需要名称来防止冲突，第一个值的默认值为零是常见的)。

然后是属性:

@property (nonatomic) TimeZone timezone;

方法头应该是这样的:

- (NSString *)toStringWithFormat:(DateFormat *)format andTimeZone:(TimeZone)timeZone {

并且只需使用kTimeZoneLocal而不是每个.Local和kTimeZoneUTC而不是每个.UTC。