Can I use App_Data folder as a normal folder in my C# ASP.NET MVC application?

Question

I understand this folder App_Data is normally for database files etc but I want this now for images, the idea being users upload images into this folder and they can be accessed from the website, I basically want App_Data to be used/thought of as a normal folder now, anyone know how to do this? Is it just permission settings or can this folder not be used like a normal folder. Thanks in advance :)

Answer 1

ApplicationData is a folder for Application Data. What kind of data you store there is up to you. Note that there are 3 on a Windows:

• ApplicationData
• CommonApplicationData
• LocalApplicationData

Generally data in there it should be data specific to this user - except for CommonApplicationData, of course. Being shared across users, is what the "Common" Prefixed Folders are there for.

However the rest of the question makes no sense. You want the user to manually put stuff there, so a WebSite can upload it? You also seem to think it is somehow not a "normal" folder?

WebSites do not have random access to the file System. So it would really just be annoying for the user to navigate there. And if there is another programm in the loop, you have not told us of it.

And the folder is quite normal. The OS stores a path to it wich can be changed (and the file moved Automagically), but beyond that it is as normal as can be. The unknown position is why you should always retreive the real values from the OS with https://learn.microsoft.com/en-us/dotnet/api/system.environment.specialfolder

Edit:

Based on your comment, I understand now. You are writing a Website. And you wonder why the server has no access to the AppData Folder. Of course only now I noticed MVC properly.

WebServers are uniquely vulnerable to hacking. Online 24/7, a few well known frameworks and widespread reachability as a core goal. As a result they generally run under the most restrictive userrights possible.

Read access to the servers programm and the Instances content directory - any more can not be expected and should never be granted. Maybe write access in a subfolder of content for Temp files - but there are better solutions, that involve Databases and HTTP Handlers.

Solution:

If you want your images to be avalible, put them into a subfolder of the Content directory for this instance. However you really should be considered Database Storage with HTTP Handlers: https://www.red-gate.com/simple-talk/sql/learn-sql-server/an-introduction-to-sql-server-filestream/ Some even go as far as having a seperate, dedicated Webserver just for Images. But I doubt you are on that scale yet.