ASP NET Core提供了一种灵活的方式来从多个来源加载配置选项。配置选项可以来自于应用程序的环境变量,命令行参数,用户定义配置文件等。您可以使用以下代码示例来演示如何使用ASP NET Core读取配置选项:
1.在Startup.cs文件中添加以下代码:
public Startup(IHostingEnvironment env)
{
var builder = new ConfigurationBuilder()
.SetBasePath(env.ContentRootPath)
.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
.AddEnvironmentVariables();
Configuration = builder.Build();
}
public IConfigurationRoot Configuration { get; }
public void ConfigureServices(IServiceCollection services)
{
// 添加配置到依赖注入容器中
services.AddSingleton(Configuration);
// 添加其他服务到依赖注入容器中
// ...
}
2.在appsettings.json配置文件中添加一些选项,例如:
{
"LogLevel": "Information",
"AllowedHosts": "*",
"ConnectionStrings": {
"DefaultConnection": "Data Source=blog.db"
}
}
3.在控制器中注入IConfiguration服务,例如:
public class HomeController : Controller
{
private readonly IConfiguration _configuration;
public HomeController(IConfiguration configuration)
{
_configuration = configuration;
}
public IActionResult Index()
{
// 读取配置选项
var logLevel = _configuration.GetValue("LogLevel");
var allowedHosts = _configuration["AllowedHosts"];
var connectionString = _configuration.GetConnectionString("DefaultConnection");
// 显示配置选项
ViewData["LogLevel"] = logLevel;
ViewData["AllowedHosts"] = allowedHosts;
ViewData["ConnectionStrings"] = connectionString;
return View();
}
}
这将演示如何使用ASP NET Core中的配置选项。您可以使用此基础来处理并注入您所需的任何配置选项。