SilverLight: DriveInfo ; Using System.IO;

David Smith

I cant get access to "DriveInfo". I added "Using System.IO;"
Do you have any clue why I cant get access to "DriveInfo"

public long GetTotalFreeSpace(string driveName)
    {
      foreach (DriveInfo drive in DriveInfo.GetDrives())
      {
        if (drive.IsReady && drive.Name == driveName)
        {
          return label.TotalFreeSpace;
        }
      }
      return -1;
    }

9 Replies

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Vulpes15y ago
Accepted answer
For security reasons Silverlight applications aren't allowed to browse the file system and consequently stuff like the DriveInfo class isn't supported.

You are allowed to use the OpenFileDialog and SaveFileDialog classes to indirectly browse it but the user has to choose the file to be opened or saved.

For most purposes it's probably best to just accept this restriction. However, if you really need to, there are ways to get around it using COM interop. See, for example, this Code Project article:

http://www.codeproject.com/KB/silverlight/FileExplorerInSilverlight.aspx
Vulpes15y ago
Yes, that's what I said in my first post.

The AutomationFactory class uses COM interop to provide access to registered automation servers.To get access to the file system on the client machine, it uses the Scripting.FileSystemObject automation server.
David Smith15y ago
I discovered you cant get access to the drive or file access with silverlight unless you are using COM. Come to find out today I am going to getting access through the service i am going to register. So this issue is resolved.
Vulpes15y ago
There's no mention in the Code Project article that RIA services need to be enabled and there's no mention in MSDN that they're needed to use AutomationFactory so I'm puzzled why you're getting an exception when you disable them.

Can you pinpoint which "operation is not supported in the current context" from the error message or debugger?
David Smith15y ago
The error i am getting is this operation is not supported in the current context when I disable RIA services. Do you know why?
Vulpes15y ago
In the 'New Silverlight Application' dialog box, there should be a checkbox to enable WCF RIA Services. Just leave it unchecked to disable them.
David Smith15y ago
I am already using that using System.Runtime.InteropServices.Automation;

I rebooted my computer and for some reason it just work. Its weird. lol. Let me troubleshoot somemore. How do you turn off RIA services. For some reason if i got asp.net default form as a start up project. It will not work. But if i am running RIA services it works fine.

The error i am getting is this operation is not supported in the current context
Vulpes15y ago
What error are you getting?

To use 'dynamic' you need .NET 4.0 which I assume you're using.

To use the AutomationFactory class, you need this using directive in your program:

using System.Runtime.InteropServices.Automation;
David Smith15y ago
I got the project set up

I can't get pass this line for some reason below within my project. When I run the project from codeproject it passes the line.

dynamic fileSystem = AutomationFactory.CreateObject("Scripting.FileSystemObject");