c# - 无法序列化字典<int, t="">在 C# 中</int,>

问题描述

我将请求模型作为参数传递给我的 POST 请求的 API，请求模型上的属性之一是 Dictionary<int, OrderFood> 类型。我正在使用 Swagger 测试操作方法，我得到的错误响应是：

“不支持集合类型'System.Collections.Generic.Dictionary`2[System.int32, OrderFood]。'”

我知道目前不支持序列化非字符串键字典，我需要实现自定义 JSON 转换器。这是请求模型类：

    [JsonConverter(typeof(JsonNonStringKeyDictionaryConverter<int, OrderFood>))]
public class FoodOrderRequestModel
{
    public string ModelName { get; set; }

    public string DisplayName { get; set; }

    public string Type { get; set; }

    public object ModelValue { get; set; }

    public object DisplayValue { get; set; }

    public Dictionary<int, OrderFood> Items { get; set; }
}

这是转换器：

internal sealed class JsonNonStringKeyDictionaryConverter<TKey, TValue> : JsonConverter<IDictionary<TKey, TValue>>
{
    public override IDictionary<TKey, TValue> Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
    {
        var convertedType = typeof(Dictionary<,>)
            .MakeGenericType(typeof(string), typeToConvert.GenericTypeArguments[1]);
        var value = JsonSerializer.Deserialize(ref reader, convertedType, options);
        var instance = (Dictionary<TKey, TValue>)Activator.CreateInstance(
            typeToConvert,
            BindingFlags.Instance | BindingFlags.Public,
            null,
            null,
            CultureInfo.CurrentCulture);
        var enumerator = (IEnumerator)convertedType.GetMethod("GetEnumerator")!.Invoke(value, null);
        var parse = typeof(TKey).GetMethod("Parse", 0, BindingFlags.Public | BindingFlags.Static, null, CallingConventions.Any, new[] { typeof(string) }, null);
        if (parse == null)
        {
            throw new NotSupportedException($"{typeof(TKey)} as TKey in IDictionary<TKey, TValue> is not supported.");
        }

        while (enumerator.MoveNext())
        {
            var element = (KeyValuePair<string?, TValue>)enumerator.Current;
            instance.Add((TKey)parse.Invoke(null, new[] { element.Key }), element.Value);
        }

        return instance;
    }

    public override void Write(Utf8JsonWriter writer, IDictionary<TKey, TValue> value, JsonSerializerOptions options)
    {
        var convertedDictionary = new Dictionary<string?, TValue>(value.Count);
        foreach (var (k, v) in value)
        {
            convertedDictionary[k?.ToString()] = v;
        }

        JsonSerializer.Serialize(writer, convertedDictionary, options);
        convertedDictionary.Clear();
    }
}

internal sealed class JsonNonStringKeyDictionaryConverterFactory : JsonConverterFactory
{
    public override bool CanConvert(Type typeToConvert)
    {
        if (!typeToConvert.IsGenericType)
        {
            return false;
        }

        if (typeToConvert.GenericTypeArguments[0] == typeof(string))
        {
            return false;
        }

        return typeToConvert.GetInterface("IDictionary") != null;
    }

    public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options)
    {
        var converterType = typeof(JsonNonStringKeyDictionaryConverter<,>)
            .MakeGenericType(typeToConvert.GenericTypeArguments[0], typeToConvert.GenericTypeArguments[1]);
        var converter = (JsonConverter)Activator.CreateInstance(
            converterType,
            BindingFlags.Instance | BindingFlags.Public,
            null,
            null,
            CultureInfo.CurrentCulture);
        return converter;
    }
}

序列化发生在我的 API 上的任何断点之前，所以我不确定如何测试我的转换器以查看它是否已添加到管道中。我也不确定 JsonNonStringKeyDictionaryConverter<,> 的位置，因为我已经看到它直接位于属性上方的某些实现。非常感谢任何建议或帮助。

标签： c#jsondictionaryasp.net-coreserialization

c# - 无法序列化字典在 C# 中

问题描述

解决方案

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