Question

我正在使用URL访问JSON文件
我从以下代码

获得此信息

    NSData* data=[jsonString dataUsingEncoding: [NSString defaultCStringEncoding] ];
    NSError *error;  //where jsonString is string of URL
    NSDictionary *jsonDictionary = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];


    if (jsonDictionary==nil) {
    NSLog(@"Error::Loading");

}else
{

    NSArray *array = [jsonDictionary objectForKey:@"categories"];
    for (int i=0; i<[array count]; i++) {
        NSMutableDictionary *dic = [[NSMutableDictionary alloc] init];
        [dic setValue:[[array objectAtIndex:i] valueForKey:@"cat_id"] forKey:@"cat_id"];
        [dic setValue:[[array objectAtIndex:i] valueForKey:@"cat_name"] forKey:@"cat_name"];
        [dic setValue:[[array objectAtIndex:i] valueForKey:@"cat_image"] forKey:@"cat_image"];
        [dic setValue:[[array objectAtIndex:i] valueForKey:@"cat_list"] forKey:@"cat_list"];
        [newsArray addObject:dic];

        [categoryArry addObject:[dic valueForKey:@"cat_name"]];
        [categoryId addObject:[dic valueForKey:@"cat_id"]];
        [categoryImage addObject:[dic valueForKey:@"cat_image"]];
        [categoryList addObject:[dic valueForKey:@"cat_list"]];
        [dic release];


    }
}

并获得json这样的结构

{
    "categories": [
        {
            "cat_id": "15",
            "cat_name": "Shop",
            "cat_image": null,
            "cat_list": [
                {
                    "sub_cat_name": "New Arrivals",
                    "Cat_Data": [
                        {
                            "prod_name": "Generals Coat Biege",
                            "prod_price": "215.0000",
                            "prod_image": "honey_beau_lookbook_winter13_febmarch-24.jpg"
                        }
                    ]
                }
            ]
        }
    ]
}

categoryArry仅包含ine值“Shop”
但我想访问categoryArry中的“sub_cat_name”并跳过商店等级....

简而言之，我想将“sub_cat_name”存储到categoryArry。

Answer 1

我正在使用名为AFNetworking的第三方库来发出JSON请求并解析响应。

以下是一个例子：

AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:@"http://yoursite.com"];

NSMutableURLRequest *request = [httpClient requestWithMethod:@"POST"
                                                             path:@"blah/path"
                                                       parameters:@{@"jsonKey":@"jsonValue"}];
AFJSONRequestOperation *operation = [AFJSONRequestOperation
                                     JSONRequestOperationWithRequest:request
                                     success:^(NSURLRequest *request, NSHTTPURLResponse *res, id json) {

                                     // Use the json here    
                                     json[@"categories"][0][@"cat_list"];

                               } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id json) {
                                     //Handle Errors
                               }];
[operation start];

Answer 2

在你的代码替换：

  [categoryArry addObject:[dic valueForKey:@"cat_name"]];

通过

   [categoryArry addObject:[[dic valueForKey:@"cat_list"][0]] valueForKey:@"sub_cat_name"];

无论如何，您可以直接使用jsonDictionary，而不是创建另一个dict。

Answer 3

当然你只需要这样做：

NSArray *catlist = [dic valueForKey:@"cat_list"]
NSDictionary *firstcat = [catlist objectAtIndex:0];
NSString *subcatname = [firstcat valueForKey:@"sub_cat_name"];

当然，假设您在cat_list数组中至少有一个项目。

从Json URL访问Dictionary

3 个答案: