UWP Json 到 C# 的转换

Question

我想将从网上获取的一些 json 数据序列化到 classes 并使用这些数据，所以我去了 http://json2csharp.com/ 并打开了 json如下

json: [{"line_descr":"\u03a0\u0395\u0399\u03a1\u0391\u0399\u0391\u03a3 - 
\u0392\u039f\u03a5\u039b\u0391","line_descr_eng":"PEIRAIAS - VOYLA"}]

对此class:

    public class RootObject
    {
        public string line_descr { get; set; }
        public string line_descr_eng { get; set; }
    }

这是我的代码：

class LineName
{
    public async static Task<RootObject> GetLineName(int linecode)
    {
        var http = new HttpClient();
        var response = await http.GetAsync("http://telematics.oasa.gr/api/?act=getLineName&p1=962");
        var result = await response.Content.ReadAsStringAsync();

        var serializer = new DataContractJsonSerializer(typeof(RootObject));
        var ms = new MemoryStream(Encoding.UTF8.GetBytes(result));
        var data = (RootObject)serializer.ReadObject(ms);

        return data;
    }
}

[DataContract]
public class RootObject
{
    [DataMember]
    public string line_descr { get; set; }

    [DataMember]
    public string line_descr_eng { get; set; }
}


    private async void Button_Click(object sender, RoutedEventArgs e)
    {
        RootObject myLine = await LineName.GetLineName(92);
        ResultTextBlock.Text = myLine.line_descr_eng;
    }

因此，当我尝试获取数据并将其显示在我的文本块中时，出现错误：line_descr_eng 为空。

谁能指出问题出在哪里？因为 line_descr_eng 应该是 PEIRAIAS - VOYLA 但我的是空的，经过大量搜索我无法找到错误所在。

Answer 1

你的json是数组，不是对象，你应该反序列化成数组。

public async static Task<RootObject[]> GetLineName(int linecode)
{
    var http = new HttpClient();
    var response = await http.GetAsync("http://telematics.oasa.gr/api/?act=getLineName&p1=962");
    var result = await response.Content.ReadAsStringAsync();

    var serializer = new DataContractJsonSerializer(typeof(RootObject[]));
    var ms = new MemoryStream(Encoding.UTF8.GetBytes(result));
    var data = (RootObject[])serializer.ReadObject(ms);

    return data;
}
//...


 var myLines = await LineName.GetLineName(92);
 var myLine = myLines.FirstOrDefault();

你也不需要内存流，你可以从 http 响应中读取流

var result = await response.Content.ReadAsStreamAsync();

Answer 2

您可以像这样使用 JavaScriptSerializer class 而不是 DataContractJsonSerializer：

替换：

var serializer = new DataContractJsonSerializer(typeof(RootObject));
var ms = new MemoryStream(Encoding.UTF8.GetBytes(result));
var data = (RootObject)serializer.ReadObject(ms);

有了这个：

var ser = new JavaScriptSerializer();
var test = ser.Deserialize<List<RootObject>>(json);

如果您找不到 JavaScriptSerializer，那么您必须执行以下简单的步骤：

Right click References and do Add Reference, then from Assemblies->Framework select System.Web.Extensions.
Now you should be able to add the following to your class file:
using System.Web.Script.Serialization;

引自：

UWP Json 到 C# 的转换

UWP Json to C# conversion

c#

json

implicit-conversion

uwp