F9 Group Marketing and Technology Blog

XML is an increasingly popular way to encode documents, data, and electronic messages. There are a number of ways to programmatically create, modify, and search XML files. Since its inception, the .NET Framework’s System.Xml namespace has included classes for programmatically working with XML documents. For instance, the XmlReader and XmlWriter classes offer developers a means to read from or write to XML files in a fast, forward-only manner, while the XmlDocument class allows developers to work with an XML document as an in-memory tree representation. LINQ to XML is a new set of XML-related classes in the .NET Framework (found in the System.Xml.Linq namespace ), which enable developers to work with XML documents using LINQ’s features, syntax, and semantics. Compared to .NET’s existing XML APIs, LINQ to XML is a simpler, easier to use API. For a given task, LINQ to XML code is typically shorter and more readable than code that uses the XmlDocument or XmlReader / XmlWriter classes.

The ListView control is similar to the GridView control in many ways: both display a set of records, both support built-in sorting, paging, editing, and deleting functionality with minimal effort. The ListView differs from the GridView in two key ways: Rather than using fields, the ListView is rendered via templates, which offers the page developer much finer control over the emitted markup, and The ListView supports built-in inserting support The first installment in this series explored the ListView’s template-based rendering. This installment looks at how to use the ListView’s inserting functionality. In a nutshell, inserting data from the ListView requires two steps: defining the inserting interface via the InsertItemTemplate and specifying where the inserting interface should go via the InsertItemPosition property. Much like with editing data from within the ListView , the InsertItemTemplate can contain two-way databinding statements when using a data source control to get the inputs entered by the user from the ListView’s inserting interface into the parameters of the data source control. And like with the editing and deleting workflows, you can programmatically examine and modify the user’s submitted data before inserting the data, cancelling the operation altogether if needed. This article walks through the steps for creating a ListView that allows users to insert records.

One of the more substantive additions to the .NET Framework 3.5 and C# 3.0 and Visual Basic 9 languages was LINQ, a set of classes along with language enhancements that allow developers to use a common library and SQL-like query syntax to work with common data stores. The initial article in this series, An Introduction to LINQ , provided an overview of LINQ and its core pieces: the standard query operators, the language extensions that allow for LINQ’s query syntax, and LINQ providers. We also looked at some simple LINQ examples using both the standard query operators and the query syntax. LINQ’s standard query operators – Select , Where , OrderBy , Average , and so on – can be used as if they were instance methods of any object that implements IEnumerable<T> . For example, given a string array named FileNames we can determine how many strings in the array start with the letter “S” by using the Where and Count standard query operators like so: string[] FileNames = { … }; int count = FileNames. Where(name => name.StartsWith(”S”)).Count() ; The Where method and Count methods look like they are members of the Array class.

This article is the third installment of a four-part series that examines how to build a data-driven web applications that offers dynamic user interfaces. Over the past two articles we created a sample web application that allows for numerous law firms to log in to the site and manage their clientele.