1.编辑AppSettings.Json

WebApi项目中的AppSettings.Json, 笔者学习时在实体库新建一个json文件读取不到

"ConnectionStrings": {
    "DefaultConnection": "Data Source=.;Initial Catalog=DataBaseName;User Id=UserName;Password=Password;"
  }

2.引用 Microsoft.Extensions.Configuration 相关包

nuget 引用以下三个包

Microsoft.Extensions.Configuration

Microsoft.Extensions.Configuration.FileExtensions

Microsoft.Extensions.Configuration.Json

3.创建 类 AppSettingsJson.cs

public static class AppSettingsJson
    {
        public static string ApplicationExeDirectory()
        {
            var location = System.Reflection.Assembly.GetExecutingAssembly().Location;
            var appRoot = Path.GetDirectoryName(location);
            return appRoot;
        }
        public static IConfigurationRoot GetAppSettings()
        {
            string applicationExeDirectory = ApplicationExeDirectory();
            var builder = new ConfigurationBuilder()
            .SetBasePath(applicationExeDirectory)
            .AddJsonFile("appsettings.json");
            return builder.Build();
        }

    }

4. 使用

var appSettingsJson = AppSettingsJson.GetAppSettings();
//方法一
var connectionString = appSettingsJson["ConnectionStrings:DefaultConnection"];
//方法二
var connectionString = appSettingsJson.GetConnectionString("DefaultConnection");
//方法三
var connectionString = appSettingsJson.GetSection("ConnectionStrings")["DefaultConnection"];