asp.net-core-2.0 - ASP.NET Core 2.0中间件-访问配置设置

Question

在asp.net核心Web API中间件中，是否可以访问中间件中的配置？有人可以指导我如何做吗？

Answer 1

在middle-ware中，您可以访问设置。为此，您需要在IOptions<AppSettings>构造函数中获取middle-ware。请参阅以下示例。

public static class HelloWorldMiddlewareExtensions
{
    public static IApplicationBuilder UseHelloWorld(
        this IApplicationBuilder builder)
    {
        return builder.UseMiddleware<HelloWorldMiddleware>();
    }
}

public class HelloWorldMiddleware
{
    private readonly RequestDelegate _next;
    private readonly AppSettings _settings;

    public HelloWorldMiddleware(
        RequestDelegate next,
        IOptions<AppSettings> options)
    {
        _next = next;
        _settings = options.Value;
    }

    public async Task Invoke(HttpContext context)
    {
        await context.Response.WriteAsync($"PropA: {_settings.PropA}");
    }
}

public class AppSettings
{
    public string PropA { get; set; }
}

有关更多信息，请参见 here。