如何使用多个密钥创建NSDictionary？

Question

我不确定我要问的是实际上是NSDictionary多用键还是好的.

我想要做的是NSDictionary为我的数据创建一个带键和值,然后将其转换为JSON格式.该JSON格式将看起来就像这样:

{
    "eventData": {
        "eventDate": "Jun 13, 2012 12:00:00 AM",
        "eventLocation": {
            "latitude": 43.93838383,
            "longitude": -3.46
        },
        "text": "hjhj",
        "imageData": "raw data",
        "imageFormat": "JPEG",
        "expirationTime": 1339538400000
    },
    "type": "ELDIARIOMONTANES",
    "title": "accIDENTE"
}

我只用过NSDictionaries这样的:

NSArray *keys = [NSArray arrayWithObjects:@"eventDate", @"eventLocation", @"latitude"  nil];
NSArray *objects = [NSArray arrayWithObjects:@"object1", @"object2", @"object3", nil]; 
dictionary = [NSDictionary dictionaryWithObjects:objects forKeys:keys];

但上述格式并非全部都与关键价值有关.所以我的问题是如何NSDictionary适应JSON格式？感谢您阅读我的帖子,对不起,如果有任何困惑.

Answer 1

你知道你可以拥有NSDictionary另一个内部NSDictonary权利吗？

NSDictionary *eventLocation = [NSDictionary dictionaryWithObjectsAndKeys:@"43.93838383",@"latitude",@"-3.46",@"latitude", nil];

NSMutableDictionary *eventData = [NSDictionary dictionaryWithObjectsAndKeys:eventLocation,@"eventLocation", nil];
[eventData setObject:@"Jun 13, 2012 12:00:00 AM" forKey:@"eventDate"];
[eventData setObject:@"hjhj" forKey:@"text"];
.
.
.
NSMutableDictionary *finalDictionary = [NSMutableDictionary dictionaryWithObjectsAndKeys:eventData,@"eventData", nil];
[finalDictionary setObject:@"ELDIARIOMONTANES" forKey:@"type"];
[finalDictionary setObject:@"accIDENTE" forKey:@"title"];

Answer 2

现在有了Objective-C文字,有一种更好,更简单,更清晰的方法来实现这一目标.这是您使用这种新语法的确切字典:

NSDictionary *dictionary = @{
    @"eventData": @{
        @"eventDate": @"Jun 13, 2012 12:00:00 AM",
        @"eventLocation": @{
            @"latitude": @43.93838383,
            @"longitude": @-3.46
        },
        @"text": @"hjhj",
        @"imageData": @"raw data",
        @"imageFormat": @"JPEG",
        @"expirationTime": @1339538400000
    },
    @"type": @"ELDIARIOMONTANES",
    @"title": @"accIDENTE"
};

// Prints: "43.93838383"
NSLog(@"%@", dictionary[@"eventData"][@"eventLocation"][@"latitude"]);