HTML5 makes it possible to develop more powerful and more user friendly web applications than we could do ever before. One of the interesting new features is support for drag and drop of files. In the past, if your application needed to provide the possibility to upload files you had to use a file selection chooser. Although this works without issues in all browsers, it is far from user friendly. In native applications, users can interact with files by using drag and drop which is much more intuitive. Luckily for us, HTML5 now also supports this and it is already supported in a number of browsers (Chrome, Firefox, Safari, …).
In this article, I will show you how we can implement drag & drop in an ASP.NET MVC3 web application. We will create a webpage containing a simple drop area that changes of color when the user is dragging a file over the page and we will update the content of the page if the file upload was successful. In order to implement the client side code, we will make use of jQuery and a jQuery plugin called “jquery-filedrop” that simplifies implementing drag & drop based file upload.