calendar_today 23 July 2015 20:05
There are a number of reasons why you might get "The 'Microsoft.ACE.OLEDB.12.0' provider is not registered on the local machine" error when attempting to connect to either an accdb or an xlsx file, depending on what you are doing. This article discusses some of the causes and provides solutions first for uses involving ASP.NET, and then looking at other application uses.
calendar_today 17 July 2015 13:43
Every time I need to work with the contents of text-based files in an ASP.NET application I invariably start off thinking about using the various static methods on the
System.IO.File class to extract the text and then some string manipulation or Regex to parse the content into some kind of structure. And, just in time, I remember the
TextFieldParser class that hides itself away in the
Microsoft.VisualBasic assembly. The purpose of this article is to introduce this component to a wider audience, but also to serve me as an aide-mémoire in terms of the basic usage, which I always have to look up.
calendar_today 07 July 2015 13:49
There are countless articles that demonstrate exporting ASP.NET GridViews to Excel. They pretty much all do the same thing - they use the RenderControl method to generate HTML and then save it to a file with a .xls extension. This kind of works, but the resulting file is actually an HTML file masquerading as an Excel file. And that has two flaws: it cannot be used as a data source because providers complain that it is not in an acceptable format, and users of Office 2007 or newer are always confronted with a warning about the contents of the file when they try to open it, causing confusion, suspicion or annoyance. This article shows how to use the free, open source library to export the content of a GridView control to a genuine .xlsx file that doesn't suffer these problems.
calendar_today 30 June 2015 14:47
This article allows me the opportunity to demonstrate a feature of my newest favourite open source library: EPPlus. EPPlus is a .net library that reads and writes Excel 2007+ files using the Open Office Xml format (xlsx). This fantastic, easy to use (and free) library enables the use of Excel in ASP.NET applications without the need to install the Access Database Engine (ACE) or having to mess about with unsupported Office Automation on the web server (assuming you can even get Office installed there). Prompted by a rash of similar questions that appeared on the ASP.NET forums recently, this article looks at reading the contents of an uploaded Excel file without saving it, and displaying the data in a Web Forms GridView.
calendar_today 18 June 2015 13:56
This article looks at how to configure Entity Framework to manage many to many relationships based on the same table. This scenario arises the same entity is related to itself in a different role. An example is the related product feature you might see in a "People also bought" section of an ecommerce site. Another is the relationship between clients and agencies in the advertising and marketing world. That scenario will form the basis of the illustration below.
calendar_today 18 May 2015 13:45
TagHelpers is one of the new features introduced in MVC 6, part of ASP.NET 5. They are used for generating reusable pieces of UI that require some kind of server-side processing. I took a closer look at the built-in collection of TagHelpers in my last article, Introducing TagHelpers in ASP.NET MVC 6. This article shows how to create your own custom TagHelpers. It will illustrate two ways of doing so: through parsing custom attributes; and by binding properties on the TagHelper.
calendar_today 11 May 2015 13:17
TagHelpers is one of the new features introduced in MVC 6. The TagHelper's role is similar to the one played in previous versions of ASP.NET MVC by HtmlHelpers: they are designed to simplify the work required to author views that need to respond dynamically to the data provided to them. However, the way in which they work and their impact on view design is very different to HtmlHelpers.
calendar_today 30 April 2015 13:26
Hardly a week goes by without someone asking a question in the ASP.NET forums about parsing HTML for one purpose or another. Mostly, the questions are couched in terms of 'finding values' or similar, prompting responses from the community that recommend one regular expression pattern or another, treating HTML as a string of text with no structure or rules. In fact, HTML is a structured document format with a set of very clearly defined rules, which means that it can easily be parsed given the right tool. My favourite tool for parsing HTML is the HtmlAgilityPack.
calendar_today 23 April 2015 13:19
This post explores the options available to you when your application requirements include managing and storing time using the Entity Framework. Specifically, I am thinking of durations of time, such as the time required to complete some kind of task, not the time part of a date. Relevant examples might include storing the length of a movie, or the preparation time required for a recipe.
calendar_today 14 April 2015 13:25
Visual Studio 2015 introduces a completely new version of ASP.NET, but it also includes version 6 of the C# language. Previous new versions of C# have heralded substantial changes like the introduction of
await in version 5,
dynamic in version 4, LINQ in version 3 and so on. There are no major feature changes or introductions in version 6, but there are a number of syntactical improvements that you are likely to use on a daily basis. Here's a rundown of them.
calendar_today 07 April 2015 13:39
ASP.NET Core is being designed so that your application is only dependent on features that it actually needs. This is achieved in large part by creating a composable framework, where the developer opts in to non-essential features - a number of which are baked in to traditional versions of ASP.NET. One of the features that this applies to is Session State. This article looks at how to obtain and use session state in ASP.NET Core applications.
calendar_today 31 March 2015 13:22
ASP.NET 5 has been largely rewritten from the ground up, and incorporates some radical changes when compared with previous versions of ASP.NET. One of the biggest changes is in the HTTP Pipeline. This article looks at how those changes impact the design and registration of plug and play components that used to be represented by HttpModules.
calendar_today 24 March 2015 13:21
This article takes a comprehensive look at the business of generating and sending email from an ASP.NET MVC application. It covers the most common use cases as well as some advanced scenarios. It also explores some of the more common errors that arise from attempting to generate and send email programmatically from an ASP.NET MVC site.
calendar_today 16 March 2015 13:20
There's a lot of confusion surrounding the numbers relating to the impending release of the next version of ASP.NET. This post takes a look at the main ones and seeks to explain their significance.
calendar_today 10 March 2015 13:07
Bang! An unhandled exception occurred during the execution of the current web request. And that's it - your visitor is met with the yellow screen of death and they are left wondering what they did wrong. You might not even be aware of what's just happened - unless your visitor can find some way of alerting you, oh, and they bother to do so. That's the problem with run time errors; the code worked fine when you ran it on your machine. But then along came a user and they tried to do something you didn't anticipate and broke your site. So what should you do about this?
calendar_today 03 March 2015 13:26
My original article about Drop Down Lists in ASP.NET MVC has proven to be among the most popular on this site, amassing over a third of a million views since it was published 5 years ago. This article builds on the original by looking at using drop down lists for multiple selections, and the helper that was introduced in MVC 5.1 to support enumerations as a source of select options.
calendar_today 24 February 2015 14:51
If you have built sites with the ASP.NET Razor Web Pages framework, you might want to look at migrating them to ASP.NET MVC at some point. This tutorial is the last in a series of three that explores how you do that by taking a step by step approach to migrating the WebMatrix Bakery template site to ASP.NET MVC 5. Previous tutorials in the series have looked at the roles of the View and Controller, and the data access and view model aspects of the Model. This final part covers model binding and form posting. A download (c. 24MB) featuring the completed application is available on GitHub.
calendar_today 18 February 2015 13:16
If you have built sites with the ASP.NET Razor Web Pages framework, you might want to look at migrating them to ASP.NET MVC at some point. This tutorial is the second in a series of three that explores how you do that by taking a step by step approach to migrating the WebMatrix Bakery template site to ASP.NET MVC 5. Along the way, each of the core parts of MVC are discussed by way of an introduction to the framework. The tutorial is divided into three parts. The first part looked at the roles of the View and Controller. This part looks at the M in MVC, the Model. Specifically, it features data access and view models. The final part will cover model binding and form posting. A download (c. 24MB) featuring the completed application is available on GitHub.
calendar_today 16 February 2015 13:33
If you have built sites with the ASP.NET Razor Web Pages framework, you might want to look at migrating them to ASP.NET MVC at some point. This tutorial is the first in a series of three that explores how you do that by taking a step by step approach to migrating the WebMatrix Bakery template site to ASP.NET MVC 5. Along the way, each of the core parts of MVC will be discussed by way of an introduction to the framework. The tutorial is divided into three parts. This first part looks at the V and C part of MVC - View and Controller. The M or Model is covered in the second and third parts. A download (c. 24MB) featuring the completed application is available on GitHub.
calendar_today 03 February 2015 13:26
ASP.NET Web API is the recommended way to build RESTful services over HTTP when using the ASP.NET stack. This article looks at incorporating Web API into an existing Razor Web Pages site, and provides a brief introduction to Web API itself.