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:

在应用程序设置中添加一个级别。json:

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

创建一个代表你的section的类:

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

在你的应用启动类中，绑定你的模型并将其注入到DI服务中:

services.Configure<MySettings>(options => Configuration.GetSection("MySettings").Bind(options));

在你的控制器中，从DI服务中获取配置数据:

public class HomeController : Controller
{
    private readonly List<string> _myArray;

    public HomeController(IOptions<MySettings> mySettings)
    {
        _myArray = mySettings.Value.MyArray;
    }

    public IActionResult Index()
    {
        return Json(_myArray);
    }
}

你也可以把你的整个配置模型存储在控制器的属性中，如果你需要所有的数据:

public class HomeController : Controller
{
    private readonly MySettings _mySettings;

    public HomeController(IOptions<MySettings> mySettings)
    {
        _mySettings = mySettings.Value;
    }

    public IActionResult Index()
    {
        return Json(_mySettings.MyArray);
    }
}

ASP。NET Core的依赖注入服务就像一个魔法一样:)

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 };
}

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;

如果你有一个像这样的复杂JSON对象数组:

{
  "MySettings": {
    "MyValues": [
      { "Key": "Key1", "Value":  "Value1" },
      { "Key": "Key2", "Value":  "Value2" }
    ]
  }
}

你可以这样检索设置:

var valuesSection = configuration.GetSection("MySettings:MyValues");
foreach (IConfigurationSection section in valuesSection.GetChildren())
{
    var key = section.GetValue<string>("Key");
    var value = section.GetValue<string>("Value");
}

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;