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:

如果你想要选择第一项的值，那么你应该这样做-

var item0 = _config.GetSection("MyArray:0");

如果你想选择整个数组的值，那么你应该这样做-

IConfigurationSection myArraySection = _config.GetSection("MyArray");
var itemArray = myArraySection.AsEnumerable();

理想情况下，您应该考虑使用官方文档建议的选项模式。这会给你带来更多的好处。

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;

对于从配置返回复杂JSON对象数组的情况，我调整了@djangojazz的答案，以使用匿名类型和动态而不是元组。

给定的设置部分:

"TestUsers": [
{
  "UserName": "TestUser",
  "Email": "Test@place.com",
  "Password": "P@ssw0rd!"
},
{
  "UserName": "TestUser2",
  "Email": "Test2@place.com",
  "Password": "P@ssw0rd!"
}],

你可以这样返回对象数组:

public dynamic GetTestUsers()
{
    var testUsers = Configuration.GetSection("TestUsers")
                    .GetChildren()
                    .ToList()
                    .Select(x => new {
                        UserName = x.GetValue<string>("UserName"),
                        Email = x.GetValue<string>("Email"),
                        Password = x.GetValue<string>("Password")
                    });

    return new { Data = testUsers };
}

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));
    }
}

从appsettings.json中获取所有section的所有值

        public static string[] Sections = { "LogDirectory", "Application", "Email" };
        Dictionary<string, string> sectionDictionary = new Dictionary<string, string>();

        List<string> sectionNames = new List<string>(Sections);
        
        sectionNames.ForEach(section =>
        {
            List<KeyValuePair<string, string>> sectionValues = configuration.GetSection(section)
                    .AsEnumerable()
                    .Where(p => p.Value != null)
                    .ToList();
            foreach (var subSection in sectionValues)
            {
                sectionDictionary.Add(subSection.Key, subSection.Value);
            }
        });
        return sectionDictionary;