Professional ASP.NET 3.5 SP1 Edition: In C# and VB

Chapter 25. File I/O and Streams

Although most of this book concentrates specifically on learning and using the features of ASP.NET 3.5, .NET provides an enormous amount of additional functionality in other areas of the Base Class Library (BCL). This chapter examines a few of the common base classes that you can use to enhance your ASP.NET applications. First, you look at using the frameworks System.IO namespace to manage files on the local file system. Next, you explore how to use the various Stream classes within the framework to read from and write different data formats to memory and the local file system. Finally, you learn how to use the .NET Framework to communicate with other computers across the Internet using common protocols such as HTTP and FTP.

AWord about I/O Security

Although this chapter is not specifically about ASP.NET security, you need to understand the impact of local system security on what the ASP.NET Worker Process is allowed to do inside of the IO namespace. Remember that generally, when your code is executed by IIS, it executes under the context of the ASP.NET Worker Process user account (ASPNET) and, therefore, your application may be restricted by that account's security rights. For example, by default, the ASP.NET Worker Process does not have rights to write to the local disk. The two main areas that you should look at to get a very basic understanding of the impact of security on an application are impersonation and user account ACLs. ASP.NET security ...