Finding out total and free disk space in .NET

Question

I am trying to find a way to determine the total and available disk space in an arbitrary folder from a .NET app. By \"total disk space\" and \"available disk space\" in a f

Answer 1

Maksim Sestic has given the best answer, as it works on both, local and UNC paths. I have changed his code a little for better error handling and included an example. Works for me like a charm.

You need to put

Imports System.Runtime.InteropServices

into your code, to allow DllImport to be recognized.

Here is the modified code:

<DllImport("kernel32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function GetDiskFreeSpaceEx(lpDirectoryName As String, ByRef lpFreeBytesAvailable As ULong, ByRef lpTotalNumberOfBytes As ULong, ByRef lpTotalNumberOfFreeBytes As ULong) As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function

Public Shared Function GetDriveSpace(folderName As String, ByRef freespace As ULong, ByRef totalspace As ULong) As Boolean

Dim free As ULong = 0
Dim total As ULong = 0
Dim dummy2 As ULong = 0

Try

    If Not String.IsNullOrEmpty(folderName) Then

         If Not folderName.EndsWith("\") Then
             folderName += "\"
         End If

         If GetDiskFreeSpaceEx(folderName, free, total, dummy2) Then
             freespace = free
             totalspace = total
             Return True
         End If

     End If

Catch
End Try

    Return False

End Function

Call it this way:

dim totalspace as ulong = 0
dim freespace as ulong = 0
if GetDriveSpace("\\anycomputer\anyshare", freespace, totalspace) then
    'do what you need to do with freespace and totalspace
else
    'some error
end if

The foldername can also be a local directory like drive:\path\path\...

It is still in VB.NET but shouldn't be a problem to translate into C#.

Answer 2

Here's one more possibility that I've used for years. The example below is VBScript, but it should work with any COM-aware language. Note that GetDrive() works on UNC shares as well.

Dim Tripped
Dim Level

Tripped = False
Level   = 0

Sub Read(Entry, Source, SearchText, Minimum, Maximum)

    Dim fso
    Dim disk

    Set fso  = CreateObject("Scripting.FileSystemObject")

    Set disk = fso.GetDrive(Source)

    Level = (disk.AvailableSpace / (1024 * 1024 * 1024))

    If (CDbl(Level) < CDbl(Minimum)) or (CDbl(Level) > CDbl(Maximum)) Then
        Tripped = True
    Else
        Tripped = False
    End If

End Sub

Answer 3

I'm pretty sure this is impossible. In windows explorer, if I try to get the folder properties of a UNC directory, it gives me nothing as far as available space. Used/Available space is a characteristic of drives, not folders, and UNC shares are treated as just folders.

you have to either:
- Map a drive
- Run something on the remote machine to check disk space.

You could also run into problems with something like Distributed file system, in which a UNC/Mapped share is NOT tied to any specific drive, so there youd have to actually sum up several drives.

And what about user quotas? The drive may not be full, but the account you are using to write to that folder may have hit its limit.