// Copyright (c) .NET Foundation. All rights reserved. // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information. using System.Linq; using System.Net; using System.Text; using System.Text.Encodings.Web; using System.Threading.Tasks; using Microsoft.AspNetCore.Builder; using Microsoft.AspNetCore.Diagnostics; using Microsoft.AspNetCore.Hosting; using Microsoft.AspNetCore.Http; using Microsoft.AspNetCore.Http.Features; namespace StatusCodePagesSample { public class Startup { public void Configure(IApplicationBuilder app) { app.UseDeveloperExceptionPage(); app.UseStatusCodePages(); // There is a default response but any of the following can be used to change the behavior. // app.UseStatusCodePages(context => context.HttpContext.Response.SendAsync("Handler, status code: " + context.HttpContext.Response.StatusCode, "text/plain")); // app.UseStatusCodePages("text/plain", "Response, status code: {0}"); // app.UseStatusCodePagesWithRedirects("~/errors/{0}"); // PathBase relative // app.UseStatusCodePagesWithRedirects("/base/errors/{0}"); // Absolute // app.UseStatusCodePages(builder => builder.UseWelcomePage()); // app.UseStatusCodePagesWithReExecute("/errors/{0}"); // "/[?statuscode=400]" app.Use(async (context, next) => { // Check for ?statuscode=400 var requestedStatusCode = context.Request.Query["statuscode"]; if (!string.IsNullOrEmpty(requestedStatusCode)) { context.Response.StatusCode = int.Parse(requestedStatusCode); // To turn off the StatusCode feature - For example the below code turns off the StatusCode middleware // if the query contains a disableStatusCodePages=true parameter. var disableStatusCodePages = context.Request.Query["disableStatusCodePages"]; if (disableStatusCodePages == "true") { var statusCodePagesFeature = context.Features.Get(); if (statusCodePagesFeature != null) { statusCodePagesFeature.Enabled = false; } } await Task.FromResult(0); } else { await next(); } }); // "/errors/400" app.Map("/errors", error => { error.Run(async context => { var builder = new StringBuilder(); builder.AppendLine(""); builder.AppendLine("An error occurred, Status Code: " + HtmlEncoder.Default.Encode(context.Request.Path.ToString().Substring(1)) + "
"); var referrer = context.Request.Headers["referer"]; if (!string.IsNullOrEmpty(referrer)) { builder.AppendLine("Retry " + WebUtility.HtmlEncode(referrer) + "
"); } builder.AppendLine(""); context.Response.ContentType = "text/html"; await context.Response.WriteAsync(builder.ToString()); }); }); app.Run(async context => { // Generates the HTML with all status codes. var builder = new StringBuilder(); builder.AppendLine(""); builder.AppendLine("" + HtmlEncoder.Default.Encode(context.Request.PathBase.ToString()) + "/missingpage/
"); var space = string.Concat(Enumerable.Repeat(" ", 12)); builder.AppendFormat("
{0}{1}{2}
", "Status Code", space, "Status Code Pages"); for (int statusCode = 400; statusCode < 600; statusCode++) { builder.AppendFormat("{0}{1}{2}{3}
", statusCode, space + space, string.Format("[Enabled]{1}", statusCode, space), string.Format("[Disabled]{1}", statusCode, space)); } builder.AppendLine(""); context.Response.ContentType = "text/html"; await context.Response.WriteAsync(builder.ToString()); }); } public static void Main(string[] args) { var host = new WebHostBuilder() .UseKestrel() .UseIISIntegration() .UseStartup() .Build(); host.Run(); } } }