objective-c - 我如何在 JSONKit 中对 NSDate 字典进行 JSON 序列化

Question

我尝试使用 Jsonkit 和 Apple 的 JSON 序列化程序，但没有成功。它不断打破 geo 属性，这是一个 NSNumbers 的 nsarray。

Post* p = [[Post alloc] init];

    p.uname = @"mike";
    p.likes =[NSNumber numberWithInt:1];
    p.geo = [[NSArray alloc] initWithObjects:[NSNumber numberWithFloat:37.78583], [NSNumber numberWithFloat:-122.406417], nil ];
    p.place = @"New York City";
    p.caption = @"A test caption";
    p.date = [NSDate date];


 NSError* error = nil;

    NSString* stuff = [[p getDictionary] JSONStringWithOptions:JKParseOptionNone error:&error];

更新:检查错误是它失败的 NSDate，而不是 NSArray。如何将日期格式化程序传递给函数？

更新 2:已解决 - 好的，查看了 jsonkit 的最新提交，发现您可以这样做:

 NSDateFormatter *outputFormatter = [[NSDateFormatter alloc] init];
    [outputFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss.SSSZZZ"];

    NSString* result = [p.dictionary JSONStringWithOptions:JKSerializeOptionNone serializeUnsupportedClassesUsingBlock:^id(id object) {
        if([object isKindOfClass:[NSDate class]]) { return([outputFormatter stringFromDate:object]); }
        return(nil);
    } error:nil];

这似乎已经奏效，但请注意，JSONKit 的此功能是 WIP，因此它可能会在下一个正式版本中更改。

Answer 1

嗯——不能代表 JSONKit 或 iOS5——我使用 Stig 的 SBJSON框架。使用它，实现相当简洁:

@implementation Post

- (id) initWithName:(NSString*)Name :(NSNumber*)Likes :(NSArray*)Geo :(NSString*)Place :(NSString*)Caption :(NSDate*)Date {

   if ((self=[super init])==nil) {
       return nil;
   }
   uname = Name;
   likes = Likes;
   geo = Geo;
   place = Place;
   caption = Caption;
   date = Date;
   return self;
}

- (NSDictionary*) getAsDictionary {
   NSDateFormatter* dateFormatter = [[NSDateFormatter alloc] init];
   [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
   NSString *dateString = [dateFormatter stringFromDate:[NSDate date]];
   [dateFormatter release];

   NSDictionary* dict = [NSDictionary dictionaryWithObjectsAndKeys:uname,@"uname",
                      likes,@"likes",
                      geo,@"geo",
                      place,@"place",
                      caption,@"caption",
                      dateString,@"date",
                      nil];
   return dict;
}

@end

和

- (void)viewDidLoad {
    [super viewDidLoad];

    Post* post = [[Post alloc] initWithName:@"Mike" 
                                       :[NSNumber numberWithInt:1] 
                                       :[[NSArray alloc] initWithObjects:[NSNumber numberWithFloat:37.78583], [NSNumber numberWithFloat:-122.406417],nil] 
                                       :@"New York City" :@"A Test caption" 
                                       :[NSDate date]];

    SBJsonWriter *writer = [[SBJsonWriter alloc] init];
    NSString* json = [writer stringWithObject:[post getAsDictionary]];
    if (json == nil) {
        NSLog(@"error = %@",writer.errorTrace);
    }
    NSLog(@"json = %@",json);
    [writer release];
    [post release];
}

产生

TestJSON[52337:207] json = {"likes":1,"date":"2011-12-13 11:12:57","place":"New York City","caption":"A Test caption","uname":"Mike","geo":[37.78583,-122.4064]}