Uploading files in ASP.NET Core is largely the same as standard full framework MVC but now we can stream large files. Here I explain how
Uploading files in ASPNET Core
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Category: MVC
Create View Components in ASP.NET Core
In this post, I want to show how creating View Components in ASP.NET Core is simple and powerful and allows us to have reusable components.
Features for AdminLTE with ASP.NET Core
I want to add new cool features for AdminLTE with ASP.NET Core. The source code of this template is on GitHub #aspnetcore #adminlte #mvc #gravatar #breadcrumbs #navigation
Adding an external Microsoft login to IdentityServer4
This article shows how to implement a Microsoft Account as an external provider in an IdentityServer4 project using ASP.NET Core Identity with a SQLite database. Setting up the App Platform for the Microsoft Account To setup the app, login using your Microsoft account and open the My Applications link https://apps.dev.microsoft.com/?mkt=en-gb#/appList Click the Add an app button. Give the application a name and add your email. This app is called microsoft_id4_enrico. After you clicked the create button, you need to generate a new password. Save this somewhere for the application configuration.…
Connect ASP.NET MVC 4.6.2 project to IdentityServer4
I have a website running on ASP.NET MVC 4.5.2. I have an IdentityServer4 server running but when I try and authenticate against it I get an: invalid_request I googled a bit but I can’t find a solution. Finally, I found the way. First, in your IdentityServer4 you have to create a new client: public static IEnumerable GetClients() { return new List<client> { new Client { ClientId = “yourid”, AllowedScopes = new List<string> { “openid” }, AllowedGrantTypes = GrantTypes.Hybrid, RedirectUris = new List { “https://yoururl/signin-oidc” }, } } } When you…
Render in MVC a link with image and text
Hi guys, I want in MVC to render a text with an image as an ActionLink. For creating a simple anchor tag, we use Html.ActionLink() helper which generates anchor tag for us. If you want to create something a bit more complicated, you must create you own component. For this reason, I created the following code. It allows you to create an anchor with an image and a text. using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; using System.Web.Routing; namespace PSC.MVC.Helpers { public static class CustomHtmlHelpers { ///…
C# and HTML5: drag and Drop elements
HTML5 API includes Drag and Drop (DnD) native functionality. The event listener methods for all the drag and drop events accept Event object which has a readonly attribute called dataTransfer. The event.dataTransfer returns DataTransfer object associated with the event This is the list of events fired during the different stages: Event Description dragstart Fires when the user starts dragging of the object. dragenter Fired when the mouse is first moved over the target element while a drag is occuring. A listener for this event should indicate whether a drop is…
C# MVC: HttpContextBase from HttpContext.Current
It’s easy by using the HttpContextWrapper HttpContextBase basecontext = (new HttpContextWrapper(HttpContext.Current)); Happy coding!
Creating a URL shortener using ASP.NET WepAPI and MVC: error handling
In the two previous post I discussed about the first step to creare this application and the implementation of the business logic. Now we can implement the error handling. We have two custom exception classes: ShorturlConflictException (when a segment already exists) and ShorturlNotFoundException (when a segment isn’t found in the database). There is also a third type: an unexpected exception, for example when there is no database connection. Normally, the user will see these errors. We have to build a mechanism where these exceptions are caught and a nice error…
Creating a URL shortener using ASP.NET WepAPI and MVC: implementing the business layer
In my previsious post I discussed the first implementation of this application. In this post I’m explained how to implement the business layer. First of all you make sure the Business project references the Data, Entities and Exceptions projects. In the Exceptions project you add two new classes: ShorturlConflictException using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace PSC.Shorturl.Web.Exceptions { public class ShorturlConflictException : Exception { } } ShorturlNotFoundException using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace PSC.Shorturl.Web.Exceptions { public class ShorturlNotFoundException : Exception {…
Creating a URL shortener using ASP.NET WepAPI and MVC
In this tutorial, I use several techniques and tools. I use Microsoft Visual Studio 2015 and the latest version of all components. ASP.NET MVC: Microsoft’s modern web application framework. As the name says, it pushes you to use the MVC (model view controller) software design principle. ASP.NET Web API: Web API and MVC are used together in many applications. With MVC, the HTML of the web pages are rendered on the server, and with Web API you can, like the name says, create an API. Web API also uses the…
OWIN and Facebook: the developers of this app have not set up this app properly for Facebook Login?
Did you received this error when you try to login in your Owin app with Facebook? App Not Set Up: This app is still in development mode, and you don’t have access to it. Switch to a registered test user or ask an app admin for permissions. Solution Go to https://developers.facebook.com/ Click on the My Apps menu on the top bar and select your appThe circle next to your app name is not fully green. When you hover mouse on it, you’ll see a popup saying, "Not available to all…
C# ASP.NET MVC OWIN and Twitter authentication error
We have an MVC project using OWIN Framework to allow our users to authenticate using Twitter. However starting today, we have been getting this exception when trying to authenticate: System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure. Thanks to the power of open source we can see that the thumbprints for the twitter certificates have been coded in the Katana Project. Microsoft.Owin.Security.Twitter.TwitterAuthenticationOptions Recently some certificates must have changed and now the thumbprints no longer match. Please add a new thumb print for the "VeriSign Class 3 Public…
ASP.NET MVC Return image dynamically drawn in controller
If you have problem returning dynamically drawn image from controller below informations may help. The task looks easy and should be achieved with this code: public ActionResult Image(string text) { //Create new image Image img = new Bitmap(100, 50); Graphics g = Graphics.FromImage(img); //Do some drawing Font font = new Font("Arial", 24); PointF drawingPoint = new PointF(10, 10); g.DrawString(text, font, Brushes.Black, drawingPoint); //Return Image MemoryStream ms = new MemoryStream(); img.Save(ms, ImageFormat.Png); return new FileStreamResult(ms, "image/png"); } Unfortunately this won’t work. At least not in .NET 4.0. Perceptive person will…
ASP.NET MVC OWIN and Microsoft account
Register an app in the Microsot Account Developer Center Go to the Microsoft Account Developer Center and create a new application. After you have registered the application take note of the App ID and App Secret: Install the Nuget Package Install the Nuget Package which contains the Microsoft OAuth provider. Install-Package Microsoft.Owin.Security.MicrosoftAccount Register Provider Locate the file in your project called \App_Start\Startup.Auth.cs. Ensure that you have imported the Owin namespace: using Owin; In the ConfigureAuth method add the following lines of code: app.UseMicrosoftAccountAuthentication( clientId: "Your client ID", clientSecret: "Your client…
The current type, is an interface and cannot be constructed. Are you missing a type mapping?
You might have missed to register your Interface and class (which implements that inteface) registration in your code. e.g if the error is "The current type, xyznamespace. Imyinterfacename, is an interface and cannot be constructed. Are you missing a type mapping?" Then you must register the class which implements the Imyinterfacename in the UnityConfig class in the Register method. Using the following code as an example using System; using Microsoft.Practices.Unity; using Microsoft.Practices.Unity.Configuration; using PSC.Shorturl.Web.Business; using PSC.Shorturl.Web.Business.Implementations; namespace PSC.Shorturl.Web.App_Start { /// /// Specifies the Unity configuration for the main container. ///…
Templated Razor Delegates
What’s that? I’ll let the code do the speaking. @{ Func<dynamic, object> b = @<strong>@item</strong>; } <span>This sentence is @b(“In Bold”).</span> That could come in handy if you have friends who’ll jump on your case for using the bold tag instead of the strong tag because it’s “not semantic”. Note that the delegate that’s generated is a Func<T, HelperResult>. Also, the @item parameter is a special magic parameter. These delegates are only allowed one such parameter, but the template can call into that parameter as many times as it needs.…
ASP.NET MVC 3: Razor’s @: and syntax
Razor minimizes the number of characters and keystrokes required when writing a view template, and enables a fast, fluid coding workflow. Unlike most template syntaxes, you do not need to interrupt your coding to explicitly denote the start and end of server blocks within your HTML. The Razor parser is smart enough to infer this from your code. This enables a compact and expressive syntax which is clean, fast and fun to type. For example, the Razor snippet below can be used to iterate a list of products: When run,…
DateDiff() function in C#
I have written the following DateDiff() function in C#. VB.NET users already had it using the Micrsoft.VisualBasic.dll assembly. Now you can use it without referencing this ‘ugly’ extra assembly. using System; namespace PureSourceCode.System { public enum DateInterval { Year, Month, Weekday, Day, Hour, Minute, Second } public class DateTimeUtil { public static long DateDiff(DateInterval interval, DateTime date1, DateTime date2) { TimeSpan ts = date2 – date1; switch (interval) { case DateInterval.Year: return date2.Year – date1.Year; case DateInterval.Month: return (date2.Month – date1.Month) + (12 * (date2.Year – date1.Year)); case DateInterval.Weekday: return…