最近我还需要从appsettings中读取一个简单的字符串数组。Json文件(以及其他类似的. Json配置文件)。

对于我的方法，我创建了一个简单的扩展方法:

public static class IConfigurationRootExtensions
{
    public static string[] GetArray(this IConfigurationRoot configuration, string key)
    {
        var collection = new List<string>();
        var children = configuration.GetSection(key)?.GetChildren();
        if (children != null)
        {
            foreach (var child in children) collection.Add(child.Value);
        }
        return collection.ToArray();
    }
}

原始海报的.json文件如下所示:

{
      "MyArray": [
          "str1",
          "str2",
          "str3"
      ]
}

使用上面的扩展方法，它使读取这个数组成为一个非常简单的一行事务，如下面的例子所示:

var configuration = new ConfigurationBuilder().AddJsonFile("appsettings.json").Build();
string[] values = configuration.GetArray("MyArray");

在运行时，在值上设置一个'QuickWatch'的断点，以验证我们已经成功地将.json配置文件中的值读入一个字符串数组:

appsettings.json:

"MySetting": {
  "MyValues": [
    "C#",
    "ASP.NET",
    "SQL"
  ]
},

我的设置类：

namespace AspNetCore.API.Models
{
    public class MySetting : IMySetting
    {
        public string[] MyValues { get; set; }
    }

    public interface IMySetting
    {
        string[] MyValues { get; set; }
    }
}

Startup.cs

public void ConfigureServices(IServiceCollection services)
{
    ...
    services.Configure<MySetting>(Configuration.GetSection(nameof(MySetting)));
    services.AddSingleton<IMySetting>(sp => sp.GetRequiredService<IOptions<MySetting>>().Value);
    ...
}

Controller.cs

public class DynamicController : ControllerBase
{
    private readonly IMySetting _mySetting;

    public DynamicController(IMySetting mySetting)
    {
        this._mySetting = mySetting;
    }
}

访问值:

var myValues = this._mySetting.MyValues;

你可以像这样使用Microsoft.Extensions.Configuration.Binder包:

在你的appsettings.json中

{
      "MyArray": [
          "str1",
          "str2",
          "str3"
      ]
}

创建保存配置的对象:

 public class MyConfig
 {
     public List<string> MyArray { get; set; }
 }

在你的控制器绑定配置:

public class HomeController : Controller
{
    private readonly IConfiguration _config;
    private readonly MyConfig _myConfig = new MyConfig();

    public HomeController(IConfiguration config)
    {
        _config = config;
    }

    public IActionResult Index()
    {
        return Json(_config.Bind(_myConfig));
    }
}

这对我很管用; 创建json文件:

{
    "keyGroups": [
        {
            "Name": "group1",
            "keys": [
                "user3",
                "user4"
            ]
        },
        {
            "Name": "feature2And3",
            "keys": [
                "user3",
                "user4"
            ]
        },
        {
            "Name": "feature5Group",
            "keys": [
                "user5"
            ]
        }
    ]
}

然后，定义一些映射类:

public class KeyGroup
{
    public string name { get; set; }
    public List<String> keys { get; set; }
}

nuget packages:

Microsoft.Extentions.Configuration.Binder 3.1.3
Microsoft.Extentions.Configuration 3.1.3
Microsoft.Extentions.Configuration.json 3.1.3

然后加载它:

using Microsoft.Extensions.Configuration;
using System.Linq;
using System.Collections.Generic;

ConfigurationBuilder configurationBuilder = new ConfigurationBuilder();

configurationBuilder.AddJsonFile("keygroup.json", optional: true, reloadOnChange: true);

IConfigurationRoot config = configurationBuilder.Build();

var sectionKeyGroups = 
config.GetSection("keyGroups");
List<KeyGroup> keyGroups = 
sectionKeyGroups.Get<List<KeyGroup>>();

Dictionary<String, KeyGroup> dict = 
            keyGroups = keyGroups.ToDictionary(kg => kg.name, kg => kg);

你可以直接获得数组，而不需要在配置中增加一个新的级别:

public void ConfigureServices(IServiceCollection services) {
    services.Configure<List<String>>(Configuration.GetSection("MyArray"));
    //...
}

设置。json文件:

{
    "AppSetting": {
        "ProfileDirectory": "C:/Users/",
        "Database": {
            "Port": 7002
        },
        "Backend": {
            "RunAsAdmin": true,
            "InstallAsService": true,
            "Urls": [
                "http://127.0.0.1:8000"
            ],
            "Port": 8000,
            "ServiceName": "xxxxx"
        }
    }
}

code

代码:

public static IConfigurationRoot GetConfigurationFromArgs(string[] args, string cfgDir)
{
    var builder = new ConfigurationBuilder()
            .SetBasePath(cfgDir)
            .AddCommandLine(args ?? new string[0]) // null  in UnitTest null will cause exception
            .AddJsonFile(Path.Combine(cfgDir, "setting.json"), optional: true, reloadOnChange: true)
            .AddEnvironmentVariables()
        // .AddInMemoryollection(configDictionary)
        ;
    var config = builder.Build();
    return config;
}

你可以使用services.AddOptions<AppSettingOption>("AppSetting")或者直接从iconfigationroot对象获取Object。

var cfg = GetConfigurationFromArgs(args, appDataDirectory);
cfg.GetSection("AppSetting").Get<AppSettingOption>()

输出:

{App.AppSettingOption}
    Backend: {App.BackendOption}
    Database: {App.DatabaseOption}
    ProfileDirectory: "C:/Users/"