James McCaffrey

Programmatically posting data to a traditional ASP page is an extremely useful and well-known technique. However, I recently discovered that posting data to an ASP .NET Web application from another program is not well understood and requires several new programming tricks. In this article I'll show you how to use the HttpWebRequest class and the ASP .NET ViewState mechanism to programmatically send form data to an ASP .NET Web application and then capture the response. This will provide you with a powerful new way to write utility programs for your Web applications. (Note: This article assumes you are familiar with creating ASP .NET Web applications, using classes in the .NET Framework, and have intermediate familiarity with the C# language.) The best way to demonstrate what we will accomplish is with two screenshots. Figure 1 shows a simple ASP .NET Web applicatio... (more)

Cover Story: Understanding Base64 Encoding

If you work in a .NET environment you have probably come across Base64 encoded data. For example, Base64 encoding is used in ASP.NET for a Web application's ViewState value, as shown in Figure 1. Base64 encoding is also used to transmit binary data over e-mail. However, if you are like most of my colleagues (and me until recently) you do not have a thorough understanding of precisely what Base64 encoding is and when Base64 encoding should be used. In the this article I will explain exactly what Base64 encoding is, show you how to use the two primary .NET Framework methods that su... (more)

String Combinatorics with Visual Basic.NET

Sooner or later you'll probably find it useful to be able to create and manipulate combinations programmatically. By far the most useful kinds of combinations are string combinations. A string combination of order (n, k) is a subset of k strings chosen from a set of n strings, where order doesn't matter. For example, suppose you have the strings {"ant", "bat", "cow", "dog", "elk"}, so n = 5. If you set k = 3, there are 10 string combination elements: {"ant", "bat", "cow"} {"ant", "bat", "dog"} {"ant", "bat", "elk"} {"ant", "cow", "dog"} {"ant", "cow", "elk"} {"ant", "dog", "elk"} ... (more)