ne of Silverlight's key strengths is its ability to provide rich, interactive features. Besides using it to perform cool animations and transformations on graphics and videos, another good use of Silverlight is for developing applications that could not otherwise be developed using conventional web applications (even when using ASP.NET and AJAX). A good example of this is a signature-capturing application. Oftentimes, when you sign for an online service (such as applying for a Google AdSense account), you need to sign a contractual agreement. In place of the traditional signature, you are often requested to provide some sort of personal information (such as your birth date or mother's maiden name) to prove that you are who you are said you are. This is because there is no way you could sign (literally) on the web page, unless you print out the form, sign it, and fax it back to the service provider.
With Silverlight, you can develop an application that allows users to sign on the page itself. And with more and more people using Tablet PCs (or having access to a pen tablet such as the Wacom Intuos Pen Tablet), pen input is no longer a dream. This article will walk you through creating a Silverlight application that captures the user's actual signature. You'll also learn how the signature can be sent back to a web service for archival.
Before you get started, you would need the following components:
- Silverlight 1.1 Alpha
- Expression Blend 2 (optional)
- Visual Studio 2008 Beta 2
- ASP.NET Futures
| Author's Note: If you have Visual Studio 2008 installed, be sure to check Microsoft’s web site to see if the Silverlight 1.1 Alpha has been fixed to work with the RTM version of Visual Studio 2008. At the time of writing, Silverlight 1.1 Alpha can only work with the Beta 2 of Visual Studio 2008. By the time you read this article, Microsoft should have fixed this problem.