c# - Json反序列化，反序列化时无法将int解析成字符串。尝试使用自定义转换器类解决此问题

Question

我从 rest API 收到一个 int，我希望将 json 反序列化器放入字符串属性“Hovednummer”，但我收到一条错误消息，提示无法从 int 转换为字符串。

我尝试使用我称为 IntToStringConverter 的自定义转换器类来解决此问题。我向属性 Hovednummer [JsonConverter(typeof(IntToStringConverter))] 添加了一个 Json 属性。

但它不起作用，当我调试程序时，它甚至没有在自定义转换器类中输入任何断点。

namespace CrownData.DataInteractionLayer.DanishCrown.Models
{
    public class StemDataReadDTO
    {
        [JsonConverter(typeof(IntToStringConverter))]
        public string Hovednummer { get; set; }
        public EjerStem Ejer { get; set; }
    }


    public class IntToStringConverter : Newtonsoft.Json.JsonConverter
    {
        public override bool CanConvert(Type typeToConvert)
        {
            return typeToConvert == typeof(string);
        }

        public override bool Equals(object obj)
        {
            return base.Equals(obj);
        }

        public override int GetHashCode()
        {
            return base.GetHashCode();
        }

        public object IntToString(JsonReader reader) //, Type objectType, object existingValue, JsonSerializer serializer
        {
            if (reader.TokenType == JsonToken.Null)
                return null;
            if (reader.TokenType == JsonToken.String)
                return reader.Value;
            if (reader.TokenType == JsonToken.Integer)
                return reader.Value.ToString();

            throw new JsonReaderException(string.Format("Unexcepted token {0}", reader.TokenType));
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            throw new NotImplementedException();
        }

        public override string ToString()
        {
            return base.ToString();
        }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            throw new NotImplementedException();
        }
    }

• TryGetStemData，获取数据。这行得通，我得到了一些东西。我只希望 hovedenr 数据类型保持字符串。现在我被迫将其设置为 int。

    public bool TryGetStemData(string hovedNummer, string cvrNummer, out Models.StemDataReadDTO stemData)
    {
        string url = _dcConfig.UrlStemData;
        StemDataCreateDTO payload = new()
        {
            CVRnr = cvrNummer,
            Hovednr = hovedNummer
        };
        var stemTask = GetClientDataAsPostAsync<Models.StemDataReadDTO>(url, payload);
        stemTask.Wait();
        stemData = stemTask.Result.result;
        return stemTask.Result.succes;
    }
  

• GetClientDataAsPostAsync 方法，它是用于获取和验证响应的通用方法。

    private async Task<(bool succes, T result)> GetClientDataAsPostAsync<T>(string url, object payload, bool allowNull = false)
    {
        bool isValid = false;
        int MaxTimeout = 20;
        var cts = new CancellationTokenSource(TimeSpan.FromSeconds(MaxTimeout));
        T result = default;
        try
        {
            HttpResponseMessage response = await _client.PostAsJsonAsync(url, payload, _serializerOptions, cts.Token);
  
            if (response.IsSuccessStatusCode)
            {
                result = await JsonSerializer.DeserializeAsync<T>(await response.Content.ReadAsStreamAsync());
                if (result == null && !allowNull)
                {
                    ErrorMessage = "Ugyldigt returdata";
                }
                else
                {
                    isValid = true;
                }
  
            }
            else
            {
                ErrorMessage = (await response.Content.ReadAsStringAsync()) ?? response.ReasonPhrase;
            }
        }
        catch (TaskCanceledException e)
        {
            ErrorMessage = $"Timout: {e.Message}";
        }
        catch (Exception e)
        {
            ErrorMessage = e.Message;
        }
        return (isValid, result);
    }
  

• 我在这里设置了一些选项，但即使将 numberHandling 设置为 Write as string，我也会遇到相同的错误。

        _serializerOptions = new JsonSerializerOptions()
        {
            PropertyNamingPolicy = null,
            NumberHandling = (System.Text.Json.Serialization.JsonNumberHandling.WriteAsString),
        };
  

标签： c#asp.netjson