.NET Core控制台项目中使用DI依赖注入

本文主要介绍在.net Core 控制台程序中如何进行依赖注入，简单步骤如下

1、.NET Core Console项目安装引用Nuget包

Install-Package Microsoft.Extensions.Configuration.EnvironmentVariables
Install-Package Microsoft.Extensions.Configuration.Json
Install-Package Microsoft.Extensions.DependencyInjection
Install-Package Microsoft.Extensions.Logging.Console
Install-Package Microsoft.Extensions.Logging.Debug
Install-Package Microsoft.Extensions.Options

2、使用Nuget的界面的管理器安装：

Microsoft.Extensions.Configuration.EnvironmentVariables
Microsoft.Extensions.Configuration.Json
Microsoft.Extensions.DependencyInjection
Microsoft.Extensions.Logging.Console
Microsoft.Extensions.Logging.Debug
Microsoft.Extensions.Options

3、修改Program.cs文件

static void Main(string[] args)
        {
            var env = Environment.GetEnvironmentVariable("APP_ENVIRONMENT");

            //根据环境变量读取配置文件
            string appsetting = !string.IsNullOrEmpty(env) ? $"appsettings.{env}.json" : "appsettings.json";

            var services = new ServiceCollection();

            // 创建 config
            var configuration = new ConfigurationBuilder()
                .SetBasePath(Directory.GetCurrentDirectory())
                .AddJsonFile(appsetting, optional: false)
                .AddEnvironmentVariables()
                .Build();
            services.Configure(configuration.GetSection("ConnectionStrings"));
            //注入
            services.AddTransient();
            //注入数据库
            var defaultConnection = connectionStrings.DBConnection;
            services.AddLinqToDbContext((provider, options) =>
            {
                options.UseSqlServer(defaultConnection).UseDefaultLogging(provider);
            });
      
            
            //调用
            var serviceProvider = services.BuildServiceProvider();

            var bar = serviceProvider.GetService<*********>();
            bar.*******();

            Console.WriteLine("Hello World!");
        }