ASP.NET Core和.NET控制台项目使用多配置类

我们可以在ASP.NET Core和.NET控制台项目中使用多个配置类，来读取同一个appsettings.json配置文件。

配置类

首先我们在ASP.NET Core项目和.NET控制台项目中创建两个配置类，FirstAppSettings和SecondAppSettings：

FirstAppSettings：

public class FirstAppSettings
{
    public string? MobilePhone { get; set; }
    public int? Port { get; set; }
    public string? NoneProperty { get; set; }
}

SecondAppSettings：

public class SecondAppSettings
{
    public string? Profile { get; set; }
    public int? Port { get; set; }
    public string? NoneProperty { get; set; }
}

ASP.NET Core项目

然后我们在ASP.NET Core项目中，定义如下appsettings.json配置文件：

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*",
  "AppSettings": {
    "MobilePhone": "+8613XXXXXXX09",
    "Port": 9090,
    "Profile": "Production"
  }
}

接下来在ASP.NET Core项目的Program类中，初始化配置文件节点AppSettings和FirstAppSettings类与SecondAppSettings类的映射关系：

using AspNetCore8Configuration.Models;

namespace AspNetCore8Configuration
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var builder = WebApplication.CreateBuilder(args);

            // Add configuration files to the container.
            var env = builder.Environment;
            var configurationBuilder = new ConfigurationBuilder()
                            .SetBasePath(env.ContentRootPath)
                            .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                            .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)//这里采用appsettings.{env.EnvironmentName}.json根据当前的运行环境来加载相应的appsettings文件
                            .AddEnvironmentVariables();
            builder.WebHost.UseConfiguration(configurationBuilder.Build());
            builder.Services.Configure<FirstAppSettings>(builder.Configuration.GetSection("AppSettings"));//初始化配置文件节点AppSettings和FirstAppSettings类的映射关系
            builder.Services.Configure<SecondAppSettings>(builder.Configuration.GetSection("AppSettings"));//初始化配置文件节点AppSettings和SecondAppSettings类的映射关系

            // Add services to the container.
            builder.Services.AddControllersWithViews();

            var app = builder.Build();

            // Configure the HTTP request pipeline.
            if (!app.Environment.IsDevelopment())
            {
                app.UseExceptionHandler("/Home/Error");
            }
            app.UseStaticFiles();

            app.UseRouting();

            app.UseAuthorization();

            app.MapControllerRoute(
                name: "default",
                pattern: "{controller=Home}/{action=Index}/{id?}");

            app.Run();
        }
    }
}

然后我们在ASP.NET Core项目的Controller构造函数中，就可以注入IOptions<FirstAppSettings>和IOptions<SecondAppSettings>接口的实例来读取到配置文件了：

using AspNetCore8Configuration.Models;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Options;
using System.Diagnostics;

namespace AspNetCore8Configuration.Controllers
{
    public class HomeController : Controller
    {
        private readonly ILogger<HomeController> _logger;
        private readonly IOptions<FirstAppSettings> _optFirstAppSettings;
        private readonly IOptions<SecondAppSettings> _optSecondAppSettings;

        public HomeController(ILogger<HomeController> logger, IOptions<FirstAppSettings> optFirstAppSettings, IOptions<SecondAppSettings> optSecondAppSettings)
        {
            _logger = logger;
            _optFirstAppSettings = optFirstAppSettings;
            _optSecondAppSettings = optSecondAppSettings;
        }

        public IActionResult Index()
        {
            return View();
        }

        public IActionResult Privacy()
        {
            return View();
        }

        [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
        public IActionResult Error()
        {
            return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
        }
    }
}

执行上面HomeController的Index方法，可以看到_optFirstAppSettings.Value和_optSecondAppSettings.Value的属性值如下：

可以看到FirstAppSettings类和SecondAppSettings类，都从配置文件appsettings.json中读取到了配置信息。

如果我们在配置文件appsettings.json中删除AppSettings节点，那么FirstAppSettings类和SecondAppSettings类读取不到任何属性值：

此外，我们也可以在ASP.NET Core项目的Program类中不初始化配置文件节点AppSettings和FirstAppSettings类与SecondAppSettings类的映射关系：

namespace AspNetCore8Configuration
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var builder = WebApplication.CreateBuilder(args);

            // Add configuration files to the container.
            var env = builder.Environment;
            var configurationBuilder = new ConfigurationBuilder()
                            .SetBasePath(env.ContentRootPath)
                            .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                            .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)//这里采用appsettings.{env.EnvironmentName}.json根据当前的运行环境来加载相应的appsettings文件
                            .AddEnvironmentVariables();
            builder.WebHost.UseConfiguration(configurationBuilder.Build());

            // Add services to the container.
            builder.Services.AddControllersWithViews();

            var app = builder.Build();

            // Configure the HTTP request pipeline.
            if (!app.Environment.IsDevelopment())
            {
                app.UseExceptionHandler("/Home/Error");
            }
            app.UseStaticFiles();

            app.UseRouting();

            app.UseAuthorization();

            app.MapControllerRoute(
                name: "default",
                pattern: "{controller=Home}/{action=Index}/{id?}");

            app.Run();
        }
    }
}

然后在ASP.NET Core项目的Controller构造函数中，注入IConfiguration接口的实例，来读取appsettings.json配置文件的AppSettings节点，并映射到FirstAppSettings类和SecondAppSettings类：

using AspNetCore8Configuration.Models;
using Microsoft.AspNetCore.Mvc;
using System.Diagnostics;

namespace AspNetCore8Configuration.Controllers
{
    public class HomeController : Controller
    {
        private readonly ILogger<HomeController> _logger;
        private readonly FirstAppSettings? _firstAppSettings;
        private readonly SecondAppSettings? _secondAppSettings;

        public HomeController(ILogger<HomeController> logger, IConfiguration configRoot)
        {
            _logger = logger;
            _firstAppSettings = configRoot.GetSection("AppSettings").Get<FirstAppSettings>();//通过注入的IConfiguration接口实例configRoot，读取appsettings.json配置文件的AppSettings节点，并映射到FirstAppSettings类
            _secondAppSettings = configRoot.GetSection("AppSettings").Get<SecondAppSettings>();//通过注入的IConfiguration接口实例configRoot，读取appsettings.json配置文件的AppSettings节点，并映射到SecondAppSettings类
        }

        public IActionResult Index()
        {
            return View();
        }

        public IActionResult Privacy()
        {
            return View();
        }

        [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
        public IActionResult Error()
        {
            return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
        }
    }
}

执行上面HomeController的Index方法，可以看到_firstAppSettings和_secondAppSettings的属性值如下：

可以看到FirstAppSettings类和SecondAppSettings类，都从配置文件appsettings.json中读取到了配置信息。

如果我们在配置文件appsettings.json中删除AppSettings节点，那么FirstAppSettings类和SecondAppSettings类都为null：

.NET控制台项目

在.NET控制台项目中，为了访问appsettings.json配置文件，我们要先在项目中安装下面五个NuGet包：

Microsoft.Extensions.Configuration
Microsoft.Extensions.Configuration.Binder
Microsoft.Extensions.Configuration.FileExtensions
Microsoft.Extensions.Configuration.Json
Microsoft.Extensions.Configuration.EnvironmentVariables

然后我们在.NET控制台项目中，创建appsettings.json配置文件：

{
  "AppSettings": {
    "MobilePhone": "+8613XXXXXXX09",
    "Port": 9090,
    "Profile": "Production"
  }
}

注意要将appsettings.json文件的属性做修改，将"Copy to Output Directory"选项设置为"Copy if newer"，如下：

我们在.NET控制台项目的Program类Main方法中，构造一个IConfigurationRoot接口的实例configRoot，然后通过configRoot来读取appsettings.json配置文件的AppSettings节点，并映射到FirstAppSettings类和SecondAppSettings类，代码如下：

using Microsoft.Extensions.Configuration;

namespace Net8Configuration
{
    internal class Program
    {
        static void Main(string[] args)
        {
            FirstAppSettings? _firstAppSettings;
            SecondAppSettings? _secondAppSettings;

            var builder = new ConfigurationBuilder()
                            .SetBasePath(Directory.GetCurrentDirectory())
                            .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                            .AddEnvironmentVariables();

            IConfigurationRoot configRoot = builder.Build();

            _firstAppSettings = configRoot.GetSection("AppSettings").Get<FirstAppSettings>();//通过IConfigurationRoot接口实例configRoot，读取appsettings.json配置文件的AppSettings节点，并映射到FirstAppSettings类
            _secondAppSettings = configRoot.GetSection("AppSettings").Get<SecondAppSettings>();//通过IConfigurationRoot接口实例configRoot，读取appsettings.json配置文件的AppSettings节点，并映射到SecondAppSettings类

            Console.WriteLine("Press any key to end...");
            Console.ReadLine();
        }
    }
}

执行上面的代码，可以看到_firstAppSettings和_secondAppSettings的属性值如下：

可以看到FirstAppSettings类和SecondAppSettings类，都从配置文件appsettings.json中读取到了配置信息。

如果我们在配置文件appsettings.json中删除AppSettings节点，那么FirstAppSettings类和SecondAppSettings类都为null：

参考文献：

Configuration in ASP.NET Core
Options pattern in ASP.NET Core

posted @ 2025-06-25 11:23 PowerCoder 阅读(44) 评论(0) 收藏举报

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