如何访问IWebHostBuilder扩展中的配置

对于 IWebHostBuilder ,它用于配置 WebHost 管道

Configuration ,你需要通过考试 Configuration CustomExtension

var config = new ConfigurationBuilder()
.AddEnvironmentVariables()
.Build();

var host = new WebHostBuilder()
.UseConfiguration(config)
.UseKestrel()
.UseStartup<Startup>();

另一方面,你可以像 UseConfiguration 访问 配置 对象,但仅当 CreateWebHostBuilder(args).Build().Run()

    public static class WebHostBuilderExtension
{
    public static IWebHostBuilder CustomExtension(this IWebHostBuilder webHostBuilder)
    {
        return webHostBuilder.ConfigureServices(services => {
            var config = services.BuildServiceProvider().GetRequiredService<IConfiguration>();
            var connection = config.GetConnectionString("Default");
        });
    }
    public static void CustomAction(IServiceCollection services)
    {
        var config = services.BuildServiceProvider().GetRequiredService<IConfiguration>();
        var connection = config.GetConnectionString("Default");
    }
}

用法:

        public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .UseStartup<Startup>()
            .CustomExtension()
            .ConfigureServices(services => WebHostBuilderExtension.CustomAction(services));