I am in the process of converting a large .NET Framework project to a .NET Core project, and I have come across the following code:
public class ContentStreamingResult : ActionResult {
private Action<Stream> _onExecuteAction;
public ContentStreamingResult(Action<Stream> onExecuteAction) {
_onExecuteAction = onExecuteAction;
}
public override void ExecuteResult(ControllerContext context) {
var httpContext = context.HttpContext;
httpContext.Response.BufferOutput = false;
_onExecuteAction(httpContext.Response.OutputStream);
}
}
There is no BufferOutput property on the HttpResponse class in .NET Core.
What is the equivalent of the HttpResponseBase.BufferOutput property in ASP.NET Core 2?
For enabling Buffering in Asp.Net Core, you could use UseResponseBuffering middleware in Startup like below:
app.UseResponseBuffering();
After applying the Buffering Middleware, if you want to disable buffer for specific requests, you could try code below:
var bufferingFeature = httpContext.Features.Get<IHttpBufferingFeature>();
bufferingFeature?.DisableResponseBuffering();
You can use IHttpResponseBodyFeature for response buffer or IHttpRequestBodyFeature for request buffer.
httpContext.Features.Get<IHttpResponseBodyFeature>().DisableBuffering()
Related
I'm writing an app using WebAssembly Blazor hosted by ASP.NET Core. Some of pages are implemented in Blazor, but some old pages are still ASP.NET Core Razor views. I need to create a link in Blazor component pointing to action of controller on server.
I can write:
NavigationManager.NavigateTo("SomeContoller/SomeAction/123", true)
But I don't want to hardcode url to action, because changing server routing or contoller/action names will break such links. Is there any way to create proper links via some helper, similar to ASP.Net Core UriHelper? Like:
UriHelper.Action("SomeAction", "SomeController", new {id = 123});
In Blazor server apps you can use LinkGenerator. The usage is not much different that of UriHelper:
#using Microsoft.AspNetCore.Routing
#inject LinkGenerator LinkGenerator
Sign in
ReSharper understands this one too, so you will get auto-completion for controller and action names.
In WebAssembly apps LinkGenerator is not available, so your best bet is to dump all routes from the server and implement your own link generator which uses that data on the client (its complexity depends on complexity of your routes, the one from ASP.NET Core is quite complex).
using Microsoft.AspNetCore.Mvc;
using System.Collections.Generic;
using System.Linq;
using Microsoft.AspNetCore.Mvc.Controllers;
using Microsoft.AspNetCore.Routing;
namespace BlazorTest.Server.Controllers
{
[Route("api/routes")]
[ApiController]
public class RouteInformationController : ControllerBase
{
private readonly EndpointDataSource _endpointDataSource;
public RouteInformationController(EndpointDataSource endpointDataSource)
{
_endpointDataSource = endpointDataSource;
}
public IEnumerable<object> Get()
{
foreach (var endpoint in _endpointDataSource.Endpoints.OfType<RouteEndpoint>())
{
var actionDescriptor = endpoint.Metadata.GetMetadata<ControllerActionDescriptor>();
if (actionDescriptor == null)
continue;
yield return new
{
actionDescriptor.ControllerName,
actionDescriptor.ActionName,
Parameters = actionDescriptor.Parameters.Select(p => p.Name),
RoutePattern = endpoint.RoutePattern.RawText,
};
}
}
}
}
You can create a static class with constant properties in it for all the URLs that you use in the app. After that use the same static class property in both the page route and your navigation route. Below is a very basic version of this:
public static class RouteUrls
{
public static string Home = "/Home";
public static string ProductList = "/Product";
public static string ProductDetail = "/Product/Detail";
public static string SomePage = "/SomeContoller/SomeAction";
}
// to access it use like this:
NavigationManager.NavigateTo($"{RouteUrls.SomePage}/123", true)
I'm reading through Adam Freeman's Pro ASP.NET Core MVC 2 and one of the chapters about advanced routing features includes a mechanism whereby you can implement two-way legacy URL handling via IRouter. The gist of it is this:
Suppose you have a "legacy" URL like "/article/Windows_3.1_Overview.html"
Using a custom IRouter implementation, Core 2.0 lets you:
Direct that legacy URL to a specific action (e.g. Legacy/GetLegacyUrl) while passing in the URL as a parameter as so:
public async Task RouteAsync(RouteContext context)
{
string requestedUrl = context.HttpContext.Request.Path.Value.TrimEnd('/');
if (urls.Contains(requestedUrl, StringComparer.OrdinalIgnoreCase))
{
context.RouteData.Values["controller"] = "Legacy";
context.RouteData.Values["action"] = "GetLegacyUrl";
context.RouteData.Values["legacyUrl"] = requestedUrl;
await mvcRoute.RouteAsync(context); // mvcRoute is an instance of MvcRouteHandler
}
}
Generate that same URL using a tag helper: (<a asp-route-legacyurl="/article/Windows_3.1_Overview.html">Old Link</a>) using the following:
public VirtualPathData GetVirtualPath(VirtualPathContext context)
{
if (context.Values.ContainsKey("legacyUrl"))
{
string url = context.Values["legacyUrl"] as string;
if (urls.Contains(url))
{
return new VirtualPathData(this, url);
}
}
return null;
}
My question is: how do I do that in Core 3.0? I've tried this approach but there is no MvcRouteHandler anymore. I've tried implementing DynamicRouteValueTransformer like so:
public async override ValueTask<RouteValueDictionary> TransformAsync(HttpContext httpContext,
RouteValueDictionary values)
{
string requestedUrl = httpContext.Request.Path.Value.TrimEnd('/');
return await Task.FromResult(new RouteValueDictionary()
{
["controller"] = "Legacy",
["action"] = "GetLegacyUrl",
["legacyUrl"] = requestedUrl
});
}
... but as far as I've read, this only works one way. It's also the only thing mentioned in Microsoft's 2.2 -> 3.0 migration guide. I've tried to just literally map the URL using
routes.MapRoute(
name: "",
template: route,
defaults: new { controller = "Legacy", action = "GetLegacyUrl", legacyUrl = route });
But this also doesn't generate the legacy URL, instead opting for Legacy/GetLegacyUrl/?legacyUrl=%2Farticle%2FWindows_3.1_Overview.html
I'm not really sure how else I can achieve this and I've been racking my brain and the documentation for several hours now. "Routing in ASP.NET Core" didn't help, neither did "Migrate from ASP.NET Core 2.2 to 3.0".
I'm probably missing something obvious, but I just can't seem to find an answer.
You could get the default mvc route handler using routes.DefaultHandler
In LegacyRoute.cs file, change your constructor signature from
public LegacyRoute(IServiceProvider services, params string[] targetUrls)
To
public LegacyRoute(IRouter routeHandler, params string[] targetUrls)
In Startup.cs file, add the route like this given below
routes.Routes.Add(new LegacyRoute(routes.DefaultHandler, "/articles/Windows_3.1_Overview.html", "/old/.NET_1.0_Class_Library"));
Upgrading to asp.net core 2.2 in my hobby project there is a new routing system I want to migrate to. Previously I implemented a custom IRouter to be able to set the controller for the request dynamically. The incoming request path can be anything. I match the request against a database table containing slugs and it looks up the a matching data container class type for the resolved slug. After that I resolve a controller type that can handle the request and set the RouteData values to the current HttpContext and passing it along to the default implementation for IRouter and everything works ok.
Custom implementaion of IRouter:
public async Task RouteAsync(RouteContext context)
{
var requestPath = context.HttpContext.Request.Path.Value;
var page = _pIndex.GetPage(requestPath);
if (page != null)
{
var controllerType = _controllerResolver.GetController(page.PageType);
if (controllerType != null)
{
var oldRouteData = context.RouteData;
var newRouteData = new RouteData(oldRouteData);
newRouteData.Values["pageType"] = page.PageType;
newRouteData.Values["controller"] = controllerType.Name.Replace("Controller", "");
newRouteData.Values["action"] = "Index";
context.RouteData = newRouteData;
await _defaultRouter.RouteAsync(context);
}
}
}
A controller to handle a specific page type.
public class SomePageController : PageController<PageData>
{
public ActionResult Index(PageData currentPage)
{
return View("Index", currentPage);
}
}
However I got stuck when I'm trying to figure out how I can solve it using the new system. I'm not sure where I'm suppose to extend it for this behavior. I don't want to turn off the endpoint routing feature because I see an opportunity to learn something. I would aso appreciate a code sample if possible.
In ASP.NET 3.0 there is an new dynamic controller routing system. You can implement DynamicRouteValueTransformer.
Documentation is on the way, look at the github issue
I’m developing a web application using Razor Pages and Code First.
I know that in ASP.NET MVC, you can use Remote above a property referring to an action in a controller that validates the data without the whole page being posted back. But it doesn’t seem to work in Razor Pages as there’s no Controller and Action in ASP.NET Core Razor Pages.
So, How can I get remote validation done in Razor Pages?
For anyone like me who finds this later and loses their mind trying to pass a property from their model onto the validation method, make the method signature look like so
public IActionResult IsCharacterNameAvailable([Bind(Prefix = "Character.Name")] string name)
Character is the model and Name is the property. Without adding the [Bind(Prefix = "")] before the parameter I was always receiving a null value. Hope this helps!
I added the following in my model class:
[Remote(action: "IsNationalIdValid",controller:"Validations")]
I created 'Controllers' folder in my Razor Pages project and added a controller(ValidationsController) with the following method:
public IActionResult IsNationalIdValid(string nationalId){}
However,when I tried to go to the page where this validation was supposed to work,I got the following exception:
No URL for remote validation could be found in asp.net core
Thanks to a reply to the same thread in Asp.Net forum,I figured out the answer:
All I needed to do was to add the following code in Startup.cs file of my Razor Pages project in order to configure the route.
app.UseMvc(routes =>
{
routes.MapRoute(
name: "default",
template: "{controller=Home}/{action=Index}/{id?}");
});
Hope this answer will help someone else as well.
In the base class that RemoteAttribute derives from there's a protected GetUrl() method than can be overriden. Therefore I created my own MyRemoteAttribute class
public class MyRemoteAttribute : RemoteAttribute
{
/// <summary>
/// Initialise an instance of the <see cref="MyRemoteAttribute"/>
/// </summary>
/// <param name="handler">The name of the Razor Page Handler</param>
/// <param name="page">The Razor Page name</param>
public MyRemoteAttribute(string handler = null, string page = null)
{
Handler = handler;
Page = page;
}
/// <summary>
/// Gets/sets the url to use for remote validation
/// </summary>
public string Url { get; set; }
public string Page { get; private set; }
public string Handler { get; private set; }
protected override string GetUrl(ClientModelValidationContext context)
{
// Use an URL is specified
if (!string.IsNullOrEmpty(Url)) return Url;
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (string.IsNullOrEmpty(Handler))
{
throw new InvalidOperationException("No Handler specified");
}
var services = context.ActionContext.HttpContext.RequestServices;
var factory = services.GetRequiredService<Microsoft.AspNetCore.Mvc.Routing.IUrlHelperFactory>();
var urlHelper = factory.GetUrlHelper(context.ActionContext);
var page = Page?? context.ActionContext.RouteData.Values["page"] as string;
Url = urlHelper.Page(page, Handler);
if (Url == null)
{
throw new InvalidOperationException();
}
return Url;
}
}
In my app which is using areas, creates a url /BusinessPartners/Clients/Create?handler=CheckUnique
To use decorate your model property with [MyRemote(Url="/Something/Somecheck")] to use the specified URL, or [MyRemote("CheckUnique")] to specify the Razor Page Handler. The handler should be named OnGet<handlername> and needs to return a JsonResult with true for passing validation, false or null if validation fails.
The handler in the Razor Page is:
public IActionResult OnGetCheckUnique(string shortName)
{
var found = db.Queryable<BusinessPartner>().Any(a => a.ShortName == shortName);
return new JsonResult(!found);
}
This is the same as you would do for the RemoteAttribute with the exception on the slightly modified naming convention.
I like my validation to be close to the point where it is used so therefore I've put it in the same page. I also have use a single [BindProperty] for a model class just to keep things neat and manageable.
Looks like there is a feature request for remote validation in ASP.NET Core Razor Pages but it is not priority:
https://github.com/aspnet/Mvc/issues/8245
The PageRemoteValidation attribute was introduced in ASP.NET Core 3.0 and is designed specifically to work with a Razor Pages handler method.
So, if you are working with ASP.NET Core 2.x, or your validation endpoint is an MVC controller, you must use the RemoteValidation attribute. If you are working with ASP.NET Core 3.x or newer, AND your validation service is a Razor Pages handler method, you must use the PageRemoteValidation attribute.
Here is an example describing this in details:
I'm trying to work on ASP.NET 5 application. Here is a class and it looks good (no red curly underlines). But when I try to build, it gives error - SymmetricAlgorithm' does not contain a definition for 'Create'
using System;
using System.IO;
using System.Security.Cryptography;
namespace SalesBook
{
public static class Encryptor
{
private static byte[] EncryptString(string data)
{
byte[] byteData = Common.GetByte(data);
SymmetricAlgorithm algo = SymmetricAlgorithm.Create();
}
}
}
I'm using .net 4.6.1.
Any help?
This method has not been ported to .NET Core. The recommended alternative is to use the specific Create method associated with the algorithm you need:
var algorithm = Aes.Create();
On CoreCLR, it will automatically determine and return the best implementation, depending on your OS environement.
If you don't need .NET Core support, you can remove the dnxcore50/dotnet5.4 from your project.json.