asp.net core 自定义中间件和service

public class MMiddleware
{
private RequestDelegate nextMiddleware;

public MMiddleware(RequestDelegate next)
{
this.nextMiddleware = next;
}

public async Task Invoke(HttpContext context)
{
context.Items.Add("middlewareID",
"ID of your middleware");
await this.nextMiddleware.Invoke(context);
}
}

public static class MyMiddlewareExtensions
{
public static IApplicationBuilder UseMMiddleware
(this IApplicationBuilder app)
{
return app.UseMiddleware<MMiddleware>();
}
}

就可以app.UseMMiddleware();

在controller中可以

public IActionResult Index()
{
ViewBag.str= service.Getstring();
    ViewBag.MiddlewareID = HttpContext.Items["middlewareID"];
    return View();
}