简式:

var myArray= configuration.GetSection("MyArray")
                        .AsEnumerable()
                        .Where(p => p.Value != null)
                        .Select(p => p.Value)
                        .ToArray();

它返回一个字符串数组:

{“str1”，“str2”，“str3”}

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");
}

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:

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/"

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;

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:)