Microsoft.Extensions.Configuration 绑定字典，键中有冒号

Question

我在使用 Microsoft.Extensions.Configuration 绑定包含带有冒号 : 的键的字典时遇到问题。

我做了一个例子，它有一个字典“GoodErrorMappings”，它的键中不包含任何冒号。这些映射正确。

我创建了另一个字典“BadErrorMappings”，键中有一个冒号。在看到字典键中的第一个冒号后，该字典似乎没有正确映射。

我快速查看了源代码，但看不到一个明显的方法来覆盖冒号作为分隔符。

任何帮助将不胜感激。

多科： https://docs.microsoft.com/en-us/aspnet/core/fundamentals/configuration

程序集版本： “Microsoft.NETCore.App” “1.1.0”

C# 代码：

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using Newtonsoft.Json;

namespace OptionsTest
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var builder = new ConfigurationBuilder()
                .SetBasePath(Directory.GetCurrentDirectory())
                .AddJsonFile("appsettings.json");

            var config = builder.Build();

            var services = new ServiceCollection().AddOptions();

            services.Configure<ApiConfig>(x => config.GetSection("ApiConfig").Bind(x));

            var apiConfig = services.BuildServiceProvider().GetService<IOptions<ApiConfig>>().Value;

            Debug.WriteLine(string.Format("\r\nGoodErrorMappings: {0}", JsonConvert.SerializeObject(apiConfig.GoodErrorMappings, Formatting.Indented)));
            Debug.WriteLine(string.Format("\r\nBadErrorMappings: {0}", JsonConvert.SerializeObject(apiConfig.BadErrorMappings, Formatting.Indented)));

            Console.ReadLine();
        }
    }

    public class ApiConfig
    {
        public Dictionary<string, ErrorMapping> GoodErrorMappings { get; set; } = new Dictionary<string, ErrorMapping>();
        public Dictionary<string, ErrorMapping> BadErrorMappings { get; set; } = new Dictionary<string, ErrorMapping>();
    }

    public class ErrorMapping
    {
        public int HttpStatusCode { get; set; }
        public int ErrorCode { get; set; }
        public string Description { get; set; }
    }
}

AppSettings.json：

{
  "ApiConfig": {
    "GoodErrorMappings": {
      "/SOMEVALUE/BLAH.123": {
        "httpStatusCode": "500",
        "errorCode": "110012",
        "description": "Invalid error description 1"
      },
      "/SOMEVALUE/BLAH.456": {
        "httpStatusCode": "500",
        "errorCode": "110013",
        "description": "Invalid error description 2"
      }
    },
    "BadErrorMappings": {
      "/SOMEVALUE/BLAH:123": {
        "httpStatusCode": "500",
        "errorCode": "110012",
        "description": "Invalid error description 1"
      },
      "/SOMEVALUE/BLAH:456": {
        "httpStatusCode": "500",
        "errorCode": "110013",
        "description": "Invalid error description 2"
      }
    }
  }
}

输出：

GoodErrorMappings: {
  "/SOMEVALUE/BLAH.123": {
    "HttpStatusCode": 500,
    "ErrorCode": 110012,
    "Description": "Invalid error description 1"
  },
  "/SOMEVALUE/BLAH.456": {
    "HttpStatusCode": 500,
    "ErrorCode": 110013,
    "Description": "Invalid error description 2"
  }
}

BadErrorMappings: {
  "/SOMEVALUE/BLAH": {
    "HttpStatusCode": 0,
    "ErrorCode": 0,
    "Description": null
  }
}

Answer 1

发生这种情况的原因是冒号在配置绑定中具有特殊含义。

当在键字符串中提供时，冒号可用于标识集合。我已经在您的示例应用程序的以下代码更改中演示了它。我还将您的 BadErrorMappings 更新为绑定中的一个数组，因为这是冒号分隔符正在做的事情。

程序.cs

public class Program
    {
        public static void Main(string[] args)
        {
            var builder = new ConfigurationBuilder()
                .SetBasePath(Directory.GetCurrentDirectory())
                .AddJsonFile("appsettings.json");

            var config = builder.Build();

            var services = new ServiceCollection().AddOptions();

            services.Configure<ApiConfig>(x => config.GetSection("ApiConfig").Bind(x));
            services.Configure<Fruit>(x => config.GetSection("Fruit").Bind(x));

            var serviceProvider = services.BuildServiceProvider();
            var apiConfig = serviceProvider.GetService<IOptions<ApiConfig>>().Value;
            var fruit = serviceProvider.GetService<IOptions<Fruit>>().Value;

            Console.WriteLine(string.Format("\r\nGoodErrorMappings: {0}", JsonConvert.SerializeObject(apiConfig.GoodErrorMappings, Formatting.Indented)));
            Console.WriteLine(string.Format("\r\nBadErrorMappings: {0}", JsonConvert.SerializeObject(apiConfig.BadErrorMappings, Formatting.Indented)));
            Console.WriteLine(string.Format("\r\nFruit: {0}", JsonConvert.SerializeObject(fruit, Formatting.Indented)));

            Console.ReadLine();
        }
    }

    public class Fruit : List<string>
    {
    }

    public class ApiConfig
    {
        public Dictionary<string, ErrorMapping> GoodErrorMappings { get; set; } = new Dictionary<string, ErrorMapping>();
        public Dictionary<string, ErrorMapping[]> BadErrorMappings { get; set; } = new Dictionary<string, ErrorMapping[]>();
    }

    public class ErrorMapping
    {
        public int HttpStatusCode { get; set; }
        public int ErrorCode { get; set; }
        public string Description { get; set; }
    }

appsettings.json

{
  "ApiConfig": {
    "GoodErrorMappings": {
      "/SOMEVALUE/BLAH.123": {
        "httpStatusCode": "500",
        "errorCode": "110012",
        "description": "Invalid error description 1"
      },
      "/SOMEVALUE/BLAH.456": {
        "httpStatusCode": "500",
        "errorCode": "110013",
        "description": "Invalid error description 2"
      }
    },
    "BadErrorMappings": {
      "/SOMEVALUE/BLAH:123": {
        "httpStatusCode": "500",
        "errorCode": "110012",
        "description": "Invalid error description 1"
      },
      "/SOMEVALUE/BLAH:456": {
        "httpStatusCode": "500",
        "errorCode": "110013",
        "description": "Invalid error description 2"
      }
    }
  },
  "Fruit:0": "Apple",
  "Fruit:1": "Orange" 
}

您可以看到 aspnet 团队也在他们的单元测试中利用了这一点，因此这是预期的行为。

示例： https://github.com/aspnet/Configuration/blob/dev/test/Config.Binder.Test/ConfigurationCollectionBindingTests.cs#L396-L423

Answer 2

我找到的最简单的解决方案是将您的Dictionary<string, string> 转换为List<KeyValuePair<string, ErrorMapping>>。 JSON.NET 然后将您的 List 转换为具有 { Key: 'keyname', Value: 'value' } 形式的对象数组。如果您接受所需的模型更改，这将很有效。

使用List<KeyValuePair<string, ErrorMapping>> 而不是Dictionary<string, ErrorMapping>。

 public class ApiConfig
    {
        public List<KeyValuePair<string, ErrorMapping>> GoodErrorMappings { get; set; } = new List<KeyValuePair<string, ErrorMapping>>();
        public List<KeyValuePair<string, ErrorMapping>> BadErrorMappings { get; set; } = new List<KeyValuePair<string, ErrorMapping>>();
    }