Avalible System Drive Leters

[Noah Coad [MCP & MVP]]

How does on determain what the avalible system drive letters are (ex: C:,
D:, etc) in C#? Thanks!

-Noah Coad
Microsoft MVP & MCP

 

[José Joye]

You could use Environment.GetLogicalDrives. This returns you in an array of
strings the drives that are currently in use.

Another solution will be to use the Win32 API as follow:

[ DllImport( "Kernel32.dll", SetLastError=true )]
internal static extern int GetLogicalDrives();

private string GetFirstAvailableDrive()
{
// Get a mask representing drive currently in use bit0: is drive a:
int nDriveMask = GetLogicalDrives();

if (nDriveMask == 0)
{
// We had an error
throw new Exception("Unable to get list of drives that are currently
in use. Err is: " +
new Win32Exception().Message);
}

// get the first available drive (Starting from D: drive)
int nPos = 4; // Position on C: drive to start
for (int i = 3; i <= 25; i++)
{
nPos = nPos << 1; // Shift by one
if ((nDriveMask & nPos) == 0)
return (((char)(i + 65)).ToString());
}

// No device available
return null;
}