ios - iOS/Objective-C:将自定义对象的NSArray转换为JSON

Question

基于the accepted answer to this answer，我试图通过JSON将自定义对象数组发送到服务器。

但是，下面的序列化对象的代码崩溃了。我认为是因为NSJSONSerialization只能接受NSDictionary，而不能接受自定义对象。

NSArray <Offers *> *offers = [self getOffers:self.customer];
//Returns a valid array of offers as far as I can tell.
NSError *error;
//Following line crashes
NSData * JSONData = [NSJSONSerialization dataWithJSONObject:offers
                                                    options:kNilOptions
                                                      error:&error];

谁能建议将自定义对象数组转换为JSON的方法？

Answer 1

就像您说的那样，NSJSONSerialization仅理解字典和数组。您必须在自定义类中提供一个将其属性转换为Dictionary的方法，如下所示:

@interface Offers 
@property NSString* title;
-(NSDictionary*) toJSON;
@end

@implementation Offers
-(NSDictionary*) toJSON {
    return @{
       @"title": self.title
    };
}
@end

然后您可以将代码更改为

NSArray <Offers *> *offers = [self getOffers:self.customer];
NSMutableArray<NSDictionary*> *jsonOffers = [NSMutableArray array];
for (Offers* offer in offers) {
    [jsonOffers addObject:[offer toJSON]];
}
NSError *error;
//Following line crashes
NSData * JSONData = [NSJSONSerialization dataWithJSONObject:jsonOffers
                                                    options:kNilOptions
                                                      error:&error];