asp.net core 读取配置不同文件的两种方法

第一种是读取appsettings.json
新建的项目它默认是和源代码根目录在一起的，内容如下

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*"
}

在程序启动的Program.cs时就有如下代码

using coreapiauth;
using coreapiauth.TestWebApi.AuthCenter.Utility;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.IdentityModel.Tokens;
using System.Text;

var builder = WebApplication.CreateBuilder(args);

所以拿到builder就可以了

if (builder.Configuration["SecurityKey"]==null|| builder.Configuration["SecurityKey"].Length==0)
{
    throw new Exception("please defined key on appsettings.json [SecurityKey issuer audience] is must!");
}

在控制器中如何拿到呢？

这就需要定义构造方法了，之前默认构造方法是不带参数的，改成带参数的,不过看上去不是复写方法，和java语法不同，这种注入不需要定义什么注解它就能给你传递进来。

    using Microsoft.AspNetCore.Authentication;
    using Microsoft.AspNetCore.Authorization;
    using Microsoft.AspNetCore.Mvc;
    using Microsoft.Extensions.Configuration;
    using Microsoft.Extensions.Logging;
    using Newtonsoft.Json;
    //using TestWebApi.AuthCenter.Utility;

    namespace TestWebApi.AuthCenter.Controllers
    {
        [Route("api/[controller]")]
        [ApiController]
        public class AuthController : ControllerBase
        {
            //需要注入的服务
            private readonly ILogger<AuthController> _logger;
            private readonly IConfiguration _configuration;
            private readonly IJwtService _jwtService;

            public AuthController(IConfiguration configuration,
                ILogger<AuthController> logger,
                IJwtService jwtService)
            {
                _configuration = configuration;
                _logger = logger;
                _jwtService = jwtService;
            }

}


}

或者
···

private readonly IConfiguration _iConfiguration = null;
public ConfigurationController(IConfiguration configuration)
{
this._iConfiguration = configuration;

}

···
第二种
这种会生成一个你的程序名(.dll|.exe).config这种似乎不方便调试在源代码阶段，这个配置文件和源代码并不是在一起的，而且它默认是没有的。

using System.Configuration;
using System.Data.SqlClient;
using webapi_test.consts;
using ConfigurationManager = System.Configuration.ConfigurationManager;

namespace webapi_test.utils
{
    public class ConfigUtil
    {
        public static void init()
        {

            Configuration cfa = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            if (cfa.AppSettings.Settings["LaunchTime"] == null)
            {
                cfa.AppSettings.Settings.Add("LaunchTime", "");
                cfa.AppSettings.Settings.Add("DataSource", "");
                cfa.AppSettings.Settings.Add("InitialCatalog", "");
                cfa.AppSettings.Settings.Add("Password", "");
                cfa.AppSettings.Settings.Add("UserID", "SA");
                cfa.AppSettings.Settings.Add("ConnectTimeout", "15");
     
            }
            else
            {

                String DataSource = cfa.AppSettings.Settings["DataSource"]?.Value??"";

                if (DataSource != null&&DataSource.Length>0)
                {

              
                    String InitialCatalog = cfa.AppSettings.Settings["InitialCatalog"]?.Value??"";
                    String UserID = cfa.AppSettings.Settings["UserID"]?.Value??"";

                    int ConnectTimeout =ParseUtil.parseInt(cfa.AppSettings.Settings["ConnectTimeout"]?.Value ?? "15");
                    String Password = cfa.AppSettings.Settings["Password"]?.Value ?? "";
                    Consts.strConn= SercretCS. Conn = new SqlConnectionStringBuilder()
                        {
                            DataSource = DataSource,
                            InitialCatalog = InitialCatalog,//
                            UserID = UserID,
                            ConnectTimeout = ConnectTimeout,
                            Password = Password
                     }.ConnectionString;
    }
                    



    }
            
            cfa.AppSettings.Settings["launchTime"].Value = DateTime.Now.ToString();

            cfa.Save();



        }
       
    }
}

如果写入成功内容如下:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <appSettings>
        <add key="LaunchTime" value="xxx" />
        <add key="DataSource" value="xxx" />
        <add key="InitialCatalog" value="xxx" />
        <add key="Password" value="xxx" />
        <add key="UserID" value="SA" />
        <add key="ConnectTimeout" value="15" />
    </appSettings>
</configuration>