将 JSON 响应消息的一部分显示在文本框中时出错

Question

我正在 UWP 应用程序中解析 JSON 数据，这是我目前的工作代码：

public sealed partial class MainPage : Page
{
    public MainPage()
    {
        this.InitializeComponent();

    }

    private async void Button_Click(object sender, RoutedEventArgs e)
    {


        UsersObject MyGetRequest = await GetRequest();



        ResultTextBlock.Text = MyGetRequest.ToString() + " - ";

    }


  public static async Task<UsersObject> GetRequest()
    {
        Uri geturi = new Uri("url"); //replace your url
        System.Net.Http.HttpClient client = new System.Net.Http.HttpClient();
        System.Net.Http.HttpResponseMessage responseGet = await client.GetAsync(geturi);
        string response = await responseGet.Content.ReadAsStringAsync();
        //return response;

        var json = await responseGet.Content.ReadAsStringAsync();
        var result = JsonConvert.DeserializeObject<UsersObject>(json);
        return result;
    }

还有一个 UserObject 类：

public class UsersObject { public List<UserObject> users = new List<UserObject>(); }
public class UserObject
{
    public string username { get; set; }
    public string password { get; set; }
    public int Id { get; set; }
    public object userscol { get; set; }
    public string __href { get; set; }
}

我目前在线上遇到错误：UsersObject MyGetRequest = await GetRequest();其中说：“在 mscorlib.ni.dll 中发生了 'Newtonsoft.Json.JsonSerializationException' 类型的异常，但未在用户代码中处理

附加信息：无法将当前 JSON 数组（例如 [1,2,3]）反序列化为 'HttpDemo.UsersObject' 类型，因为该类型需要 JSON 对象（例如 {"name":"value"}）才能反序列化正确。”

我使用的 JSON 是：

[
    {
        "username": "user1",
        "password": "10",
        "Id": 1,
        "userscol": null,
        "__href": "/db/GroupDBTest/users/Id/1.json"
    },
{
        "username": "user2",
        "password": "100",
        "Id": 2,
        "userscol": null,
        "__href": "/db/GroupDBTest/users/Id/2.json"
}

]

Answer 1

问题是您的服务器返回List<UserObject>。您正在尝试将其转换为仅包含 List<UserObject> 但本身不是 List<UserObject> 的 UsersObject！

您需要执行以下操作：

public static async Task<List<UserObject>> GetRequest()
{
    Uri geturi = new Uri("url"); //replace your url
    System.Net.Http.HttpClient client = new System.Net.Http.HttpClient();
    System.Net.Http.HttpResponseMessage responseGet = await client.GetAsync(geturi);
    string response = await responseGet.Content.ReadAsStringAsync();
    //return response;

    var json = await responseGet.Content.ReadAsStringAsync();
    var result = JsonConvert.DeserializeObject<List<UserObject>>(json);
    return result;
}


private async void Button_Click(object sender, RoutedEventArgs e)
{
    UsersObject myGetRequest = new UsersObject();
    myGetRequest.users = await GetRequest();

    //to iterate all users you got do this:
    foreach(var item in myGetRequest.users)
    {
        //do something
    }
}