Latest Entries

Using Parameter Transformers To Modify Route And Parameter Values In Razor Pages

calendar_today 29 April 2019 08:45

ASP.NET Core Razor Pages

Available from ASP.NET Core 2.2, parameter transformers enable the centralisation of logic for modifying the value of routes and route parameters in URLs generated by the anchor tag helper or the Url helper.

Creating Custom Constraints For Razor Pages Routes

calendar_today 01 April 2019 09:16

ASP.NET Core Razor Pages

Razor Page already includes a wide range of constraints that can be used to help disambiguate routes. It is also possible for you to create your own custom constraint and then register that with the routing system.

Rendering A Partial To A String In Razor Pages

calendar_today 19 March 2019 08:22

ASP.NET Core Razor Pages

Partial Views or Pages are primarily used as a means of including reusable snippets of HTML within one or more Razor Pages. This walkthrough illustrates how to take advantage of the power of the Razor templating system used by partial pages to generate HTML for other purposes, such as the body of a mail message.

Global Error Handling And Logging With NLog In Razor Pages

calendar_today 12 February 2019 08:26

ASP.NET Core Razor Pages

Exceptions in .NET represent an error condition in an executing program. Error conditions can come about as a result of a large number of causes, each represented by its own exception type. Most exceptions arise from logical errors in code, such as an attempt to work with an object that has not been instantiated (NullRefrenceException), or to divide by zero (DivideByZeroException). Other types of exceptions result from technical issues, which may or may not be temporary. Examples of such issues might include a database or mail server being unavailable, or insufficient file system permissions.

Including Static Resources In Razor Class Libraries In ASP.NET Core

calendar_today 17 October 2018 13:32

ASP.NET Core Razor Pages

Razor Class libraries (RCLs) were introduced in ASP.NET Core 2.1 as a way to package and distribute UI components to be referenced and consumed within a host application. You can see them as a fully functioning part of a web application packaged as a class libray. The templated management pages for ASP.NET Identity were included as a Razor Class Library in the project template in 2.1. The Identity UI RCL includes the Razor pages, Filters, a stub EmailService class that Identity uses, and local versions of both Bootstrap 3 and 4.

Adding Sorting To Paging In ASP.NET Core Razor Pages

calendar_today 10 October 2018 08:35

ASP.NET Core Razor Pages

This article builds on the simple paging functionality that was added to a Razor Pages application in my last article by showing how to add sorting functionality so that the user can determine the order in which results are displayed.

Simple Paging In ASP.NET Core Razor Pages

calendar_today 03 October 2018 07:49

ASP.NET Core Razor Pages

This article attempts to demonstrate how to implement simple paging functionality in a Razor Pages application. I will explain the basics behind paging, and then use BootStrap 4 to render a variety of paging links, without resorting to Nuget packages for link generation.

Customising Routing Conventions In Razor Pages

calendar_today 26 September 2018 07:39

ASP.NET Core Razor Pages

At its heart, the Razor Pages routing story is a simple one. It uses a convention of mapping URLs to files on disk. There are ways to customise how pages are found on an individual basis, but what if you want to change the default convention in its entirety? There is also a way to do that. And it's quite simple, as this article will demonstrate, using two real-world examples.

Using Unobtrusive Ajax In Razor Pages

calendar_today 17 September 2018 08:17

AJAX ASP.NET Core Razor Pages

There are a few demonstrations showing how to use the jQuery Unobtrusive AJAX library in ASP.NET Core, but existing examples tend to feature MVC applications. This article looks at how to use Unobtrusive AJAX in a Razor Pages setting, where it will help to remove a lot of the boilerplate associated with making AJAX requests.

Partials and AJAX In Razor Pages

calendar_today 07 September 2018 15:57

AJAX ASP.NET Core Razor Pages

Updating portions of a page using AJAX and partial views is a routine task in ASP.NET MVC applications. The experience is little different in ASP.NET Core Razor Pages - not much, but enough to stump some people. Here is some advice on accomplishing this task, and a preview of some additional help coming in the near future.

Areas In Razor Pages

calendar_today 03 September 2018 08:01

ASP.NET Core Razor Pages

Support for Areas was added to Razor Pages with the release of ASP.NET Core 2.1. They have long been used in MVC applications as a way to separate logical chunks of large applications into semi-independent modules to facilitate team working etc. Here, I explore how to use areas in a Razor Pages application.

Accessing The Model From Filters In Razor Pages

calendar_today 29 August 2018 08:23

ASP.NET Core Razor Pages

Support for filters was added to Razor Pages with the release of ASP.NET Core 2.1. Filters, for those unfamiliar with them, are components that enable the injection of processing at certain points within the Razor Page lifecycle. They differ from Middleware in that they provide access to the HttpContext. Razor Pages offers a number of different filter options. One of the things that you might want to do in a filter is to obtain data from an external resource (database, web service etc) and then use it in the PageModel or ViewData. Here, I take a look at how you can access the model or ViewData dictionary depending on the type of filter implementation that you choose.

Query Types in Entity Framework Core

calendar_today 15 August 2018 13:46

Entity Framework ASP.NET Core

Query Types, introduced in Entity Framework Core 2.1 enable you to return non-entity types that map to tables or views and can serve as the return type from FromSql method calls.

Razor Pages, TypeScript and Knockout

calendar_today 16 July 2018 07:54

Javascript ASP.NET Core Razor Pages TypeScript

In this article, I look at the steps required to get TypeScript up and running in the context of a Razor Pages application. I discuss why you might want to do this, and I use Knockout for the purposes of demonstration. By the end of the article, I will have configured and used TypeScript to replicate part of the final code for the Single Page Application tutorial from

Improved Cascading Dropdowns With Blazor

calendar_today 05 July 2018 13:27

C# Blazor

In my last article, I looked at the experimental Blazor framework, using Cascading Dropdown Lists as an entry point. Since then, some feedback from Steve Sanderson to a question I asked has shown me a better way to implement this pattern.

Cascading Dropdowns With Blazor

calendar_today 24 May 2018 20:51

ASP.NET Core Blazor

Blazor is an experimental framework introduced by Steve Sanderson of Knockout.js fame (among other things) on the ASP.NET team. The premise of the framework is simple, but potentially game-changing for ASP.NET developers: it enables you to write your client side code in C#. What this means is that rather than having to chase after the latest Javascript-based hotness - Aurelia, React, Angular etc, only to find that they are dependent on learning a whole new load of frameworks, or that they are no longer flavour of the week, you just use the .NET skills that you already have to move your processing to the browser.

Working With JSON in Razor Pages

calendar_today 21 May 2018 13:49

ASP.NET Core Razor Pages

UI generation and processing within web applications is moving increasingly to the client. Data processing and storage is still undertaken on the server, with JSON being the preferred format for exchanging data between the server and the client. There are a number of ways in which you can generate JSON when working with Razor Pages. This article explores some of them.

Extending the Command Timeout in Entity Framework Core Migrations

calendar_today 26 March 2018 08:50

Entity Framework ASP.NET Core

Most migrations that you execute when working with Entity Framework Core are likely to be straightforward - resulting in nothing more than an adjustment to the database schema. Sometimes, however, you might also want to include a task that requires longer than the default command timeout value (30 seconds in SQL Server) such as importing a lot of data.

Publishing Razor Pages Applications - Gotchas

calendar_today 22 March 2018 08:15

ASP.NET Core Razor Pages

I have just completed an article covering publishing a Razor Pages application to IIS on my Razor Pages dedicated site: While writing it (and publishing revised versions of the site) I uncovered a few stumbling blocks that might catch others out. So I thought they were worth highlighting here in their own post.

ViewModels and AutoMapper in Razor Pages

calendar_today 14 February 2018 08:13

ASP.NET Core Razor Pages

The Razor Pages PageModel class is part controller, part ViewModel. In this article, I take a look at the ViewModel part of the role that the PageModel plays, and how tools like AutoMapper can be used to reduce the amount of code you need to write when assigning values between your entity model and your ViewModel.