Newtonsoft.Json.JsonSerializationException:C#

再會！

我在反序列化 JSON 字串時遇到問題

這是我的功能：

 public static void Deserialised()
    {
        string jsonString = "{\"data\":{\"merchantRefNo\":\"foo\","  
                            "\"responseText\":\"Approved\","  
                            "\"status\":\"A\","  
                            "\"txnDate\":\"20220321\","  
                            "\"txnId\":\"000067\","  
                            "\"txnTime\":\"1049\","  
                            "\"txnType\":\"sale\","  
                            "\"amt\":\"109\"},"  
                            "\"dataType\":\"trans\"}";

        Root myDeserializedJson = JsonConvert.DeserializeObject<Root>(jsonString); //Error popup here!

        foreach (var datas in myDeserializedJson.data)
        {
            Console.WriteLine(datas.merchantRefNo);
        }
    }

這是我的模型：

 public class Data
    {
        public string merchantRefNo { get; set; }
        public string responseText { get; set; }
        public string status { get; set; }
        public string txnDate { get; set; }
        public string txnId { get; set; }
        public string txnTime { get; set; }
        public string txnType { get; set; }
        public string amt { get; set; }
    }

    public class Root
    {
        public List<Data> data { get; set; }
        public string dataType { get; set; }
    }

錯誤：

Newtonsoft.Json.JsonSerializationException: 'Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[fortestings.Program Data]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly. To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object. Path 'data.merchantRefNo', line 1, position 25.'

uj5u.com熱心網友回復：

在您的Root班級中，更改List<Data> data為Data data，然后您可以根據班級JSON的需要反序列化您的字串Root：

using System;
using Newtonsoft.Json;
                    
public class Program
{
    public static void Main()
    {
        string jsonString = "{\"data\":{\"merchantRefNo\":\"foo\","  
            "\"responseText\":\"Approved\","  
            "\"status\":\"A\","  
            "\"txnDate\":\"20220321\","  
            "\"txnId\":\"000067\","  
            "\"txnTime\":\"1049\","  
            "\"txnType\":\"sale\","  
            "\"amt\":\"109\"},"  
            "\"dataType\":\"trans\"}";
        
        var result =JsonConvert.DeserializeObject<Root>(jsonString);
        Console.WriteLine(result.dataType);
        Console.WriteLine(result.data.merchantRefNo);
        Console.WriteLine(result.data.status);
        Console.WriteLine(result.data.txnId);           
    }
}

public class Data
{
    public string merchantRefNo { get; set; }
    public string responseText { get; set; }
    public string status { get; set; }
    public string txnDate { get; set; }
    public string txnId { get; set; }
    public string txnTime { get; set; }
    public string txnType { get; set; }
    public string amt { get; set; }
}

public class Root
{
    public Data data { get; set; }
    public string dataType { get; set; }
}

輸出：

trans
foo
A
000067

您可以在這里找到一個作業示例：https ://dotnetfiddle.net/8Nsl9m

uj5u.com熱心網友回復：

{“資料”：{“merchantRefNo”：“foo”，“responseText”：“已批準”，“狀態”：“A”，“txnDate”：“20220321”，“txnId”：“000067”，“txnTime”： "1049", "txnType":"sale", "amt":"109" }, "dataType":"trans" }

這是您的根物件 JSON，但您的班級需要一個資料串列

public class Root
{
    public **List<Data>** data { get; set; }
    public string dataType { get; set; }
}

因此，對于反序列化 json 與您的模型不匹配。您的 Json 應如下所示 { "data":[{ "merchantRefNo":"foo", "responseText":"Approved", "status":"A", "txnDate":"20220321", "txnId":" 000067", "txnTime":"1049", "txnType":"sale", "amt":"109" }], "dataType":"trans" }

標籤：c# json json.net

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