objective-c - 用于假人的Objective-C:如何在NSDictionary内部循环浏览NSDictionary？

Question

好的，我很困惑。所以，我有一个NSDictionary，它由一个JSON字符串填充，如下所示:

{"Success":true,"Devices":[{"UDId":"...","User":"...","Latitude":0.0,"Longitude":0.0}]}

现在，我知道如何检查 Success是否为 true，但是我需要遍历 Devices(JSON对象)数组并创建内部 Devices(内部应用程序对象)数组，我不知道该怎么做。有人可以解释怎么做吗？

这是我的 Device.m/h:

#import <CoreLocation/CoreLocation.h>
#import <Foundation/Foundation.h>

@interface Device : NSObject {
    NSString *udId;
    NSString *name;
    NSNumber *latitude;
    NSNumber *longitude;
}

@property (nonatomic, retain) NSString *udId;
@property (nonatomic, retain) NSString *name;
@property (nonatomic, retain) NSNumber *latitude;
@property (nonatomic, retain) NSNumber *longitude;

#pragma mark -
#pragma mark MKAnnotation Properties
@property (nonatomic, readonly) CLLocationCoordinate2D coordinate;

@end

----

#import "Device.h"

@implementation Device

@synthesize udId, name, latitude, longitude;

- (CLLocationCoordinate2D)coordinate {
    CLLocationCoordinate2D internalCoordinate;

    internalCoordinate.latitude = [self.latitude doubleValue];
    internalCoordinate.longitude = [self.longitude doubleValue];

    return internalCoordinate;
}

- (void)dealloc {
    [udId release];
    udId = nil;

    [name release];
    name = nil;

    [latitude release];
    latitude = nil;

    [longitude release];
    longitude = nil;

    [super dealloc];
}

@end

这是我应该读取响应并将其转换为可以使用的对象的方法:

- (void)requestFinished:(ASIHTTPRequest *)request {
    if (![request error]) {
        NSError *jsonError = nil;
        NSDictionary *jsonDictionary = [NSDictionary dictionaryWithJSONString:[request responseString] error:&jsonError];

        if (!jsonError || ([[jsonDictionary objectForKey:@"Success"] intValue] == 1)) {
            //  READ "DEVICES" AND CONVERT TO OBJECTS
        } else {
            //  AUTHORIZATION FAILED
        }
    }
}

我真的很感谢您的帮助。我只是似乎无法包住头...

提前致谢!

Answer 1

首先，您需要为Device类定义初始化器/构造器。

设备.h

- (id)initWithUdid:(NSString *)udid name:(NSString *)name latitude:(NSNumber *)lat longitude:(NSNumber *)lon;

设备号

- (id)initWithUdid:(NSString *)udid name:(NSString *)name latitude:(NSNumber *)lat longitude:(NSNumber *)lon {
    if (self = [super init]) {
        self.udid = udid;
        self.name = name;
        self.latitude = lat;
        self.longitude = lon;
    }
    return self;
}

然后，您可以初始化一个新对象，例如:

Device *dev = [[Device alloc] initWithUdid:@"a udid" name:@"the name" latitude:latNum longitude:lonNum];

因此，您应该能够像这样迭代数组并构建Device对象:

NSArray *devicesArray = [dict objectForKey:@"Devices"];
for (NSDictionary *d in devicesArray) {
  Device *dev = [[Device alloc] initWithUdid:[d objectForKey:@"UDId"]
                                        name:[d objectForKey:@"User"]
                                    latitude:[NSNumber numberWithDouble:[d objectForKey:@"Latitude"]]
                                   longitude:[NSNumber numberWithDouble:[d objectForKey:@"Latitude"]]];
}