JSON无法反序列化为对象,需要数组吗？

Question

我试图获取传入的JSON项目并将它们绑定到列表框项目,但我被视觉工作室告知我需要做一个数组而不是对象？我从来没有这样做过......任何人都知道怎么做？

我的RootObject:

public class RootObject
{
    public string url { get; set; }
    public string display { get; set; }
    public List<string> genetics { get; set; }
    public List<string> price { get; set; }
    public List<string> brandMaker { get; set; }
    public string form { get; set; }
    public string dosornos { get; set; }
    public string qty { get; set; }
    public string mfg { get; set; }
    public string mobURI { get; set; }
}

注意:Genetics,Price,BrandMaker实际上并不返回任何值,而是返回值,如下所示:

"genetics": [
    "typeophere"
],
"price": [
    "$1400"
],

JSON文件/请求基本结果:

  [
{
    "url": "N/A",
    "display": "",
    "genetics": [
        "microogiz"
    ],
    "price": [
        "96.016"
    ],
    "brandMaker": [
        "Oshi Kunti Multikashi, Osaka, JP"
    ],
    "form": "tangent",
    "dosornos": "n/a",
    "qty": "88G",
    "mfg": "SelfMade Industries, USA Dist.",
    "mobURI": "n/a"
}

]

我原来的代码:

// Get JSON via WEB
string ProviderURI = goURI;
webClient webClient = new WebClient();
webClient.DownloadStringCompleted += new  
    DownloadStringCompletedEventHandler(webClient_DownloadStringCompleted);
webClient.DownloadStringAsync(new Uri(ProviderURI));

void webClient_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
    if (e.Error != null)
    {
        return;
    }

    var deserializedJSON = JsonConvert.DeserializeObject<RootObject>(e.Result);
    lstBoxResults.ItemsSource = deserializedJSON; // or deserializedJSON.url.ToString();
}

Answer 1

好的,你提到遗传和价格是数组,但返回的JSON只包含一个项目.RootObject的其余部分是简单的字符串属性.

由于您没有发布原始JSON示例.让我展示一个精简版,以保持简单和简短.

{
    "url": "http://www.stackoverflow.com",
    "display": "This is a test",
    "genetics": [
        "typeophere"
    ],
    "price": [
        "$1400"
    ],
    "form": "a form"
}

现在我们可以减少RootObject类类型.我使用Pascal大小写来表示我的属性,并将它们与JSON.NET属性相关联,以帮助进行deserialing/serializing.

[JsonObject(MemberSerialization = MemberSerialization.OptIn)]
public class RootObject
{
    [JsonProperty(PropertyName = "url")]
    public string Url { get; set; }

    [JsonProperty(PropertyName = "display")]
    public string Display { get; set; }

    [JsonProperty(PropertyName = "genetics")]
    public List<string> Genetics { get; set; }

    [JsonProperty(PropertyName = "price")]
    public List<string> Price { get; set; }

    [JsonProperty(PropertyName = "form")]
    public string Form { get; set; }
}

由于我不知道您正在调用的Web服务,因此我将此JSON存储在文本文件中.将其标记为嵌入式资源并从那里读取.

string json;
var resource = Application.GetResourceStream(new Uri("json.txt", UriKind.Relative));
using (var reader = new StreamReader(resource.Stream))
{
    json = reader.ReadToEnd();
}

只需使用WebClient调用替换此部分即可获取JSON数据.

现在我们可以将JSON反序列化为RootObject实例.

var rootObject = JsonConvert.DeserializeObject<RootObject>(json);

像宣传的那样工作.现在需要将它绑定到ListBox控件.如果将鼠标悬停在ListBox实例的ItemSource属性上,您将看到工具提示提到您可以将其绑定到集合.好吧,单个rootObject不是集合.你不能直接绑定它.

lstBoxResults.ItemsSource = rootObject;

这不起作用.您无法将RootObject实例转换为System.Collections.IEnumerable.这是ItemsSource的期望.

轻松修复.让我们创建一个集合.

lstBoxResults.ItemsSource = new List<RootObject> { rootObject };

这假设您的JSON数据仅返回一个rootObject.ListBox中只会显示一个项目.

现在让我们假设您的JSON数据返回一个RootObject数组.例如,一个名为"items"的数组,其中包含RootItems的集合.

{
    "items": [
    {
    "url": "http://www.stackoverflow.com",
    "display": "This is a test",
    "genetics": [ "typeophere" ],
    "price": [ "$1400" ],
    "form": "a form"        
    },
    {
    "url": "http://cgeers.com",
    "display": "This is another test",
    "genetics": [ "typeophere" ],
    "price": [ "$2000" ],
    "form": "another form"
    }]
}

去除这一点同样容易.使用JSON.NET获取RootObjects的集合.

var data = JObject.Parse(json)["items"];

现在反序列化为一个集合(IEnumerable).

var rootObjects = JsonConvert.DeserializeObject<IEnumerable<RootObject>>(data.ToString());

由于您现在已经拥有RootObject集合,因此无需自己创建.您可以直接将其绑定到ListBox.

lstBoxResults.ItemsSource = rootObjects;

似乎您收到的JSON数据无效.在解析之前,请确保修改它以便拥有有效的JSON对象.

例如:

json = json.Substring(json.IndexOf("[") + 1);
json = json.Substring(0, json.LastIndexOf("]"));
var rootObjects = JsonConvert.DeserializeObject<RootObject>(json);

Answer 2

试试这个

RootObject rootObject;

if (json.startsWith("["))
{
  rootObject = JsonConvert.DeserializeObject<List<RootObject>>(json)[0];
}
else
{
  rootObject = JsonConvert.DeserializeObject<RootObject>(json);
}