How can I determine if a given drive letter is a l

问题:

Given the letter of a drive, how can I determine what type of drive it is?

For example, whether E:\ is a USB drive, a network drive or a local hard drive.

回答1:

Have a look at DriveInfo's DriveType property.

System.IO.DriveInfo[] drives = System.IO.DriveInfo.GetDrives();
foreach (var drive in drives)
{
    string driveName = drive.Name; // C:\, E:\, etc:\

    System.IO.DriveType driveType = drive.DriveType;
    switch (driveType)
    {
        case System.IO.DriveType.CDRom:
            break;
        case System.IO.DriveType.Fixed:
            // Local Drive
            break;
        case System.IO.DriveType.Network:
            // Mapped Drive
            break;
        case System.IO.DriveType.NoRootDirectory:
            break;
        case System.IO.DriveType.Ram:
            break;
        case System.IO.DriveType.Removable:
            // Usually a USB Drive
            break;
        case System.IO.DriveType.Unknown:
            break;
    }
}

回答2:

Just for reference for anyone else, this is what I turned GenericTypeTea's answer into:

/// <summary>
/// Gets the drive type of the given path.
/// </summary>
/// <param name="path">The path.</param>
/// <returns>DriveType of path</returns>
public static DriveType GetPathDriveType(string path)
{
    //OK, so UNC paths aren't 'drives', but this is still handy
    if(path.StartsWith(@"\\")) return DriveType.Network;  
    var info = 
          DriveInfo.GetDrives()
          Where(i => path.StartsWith(i.Name, StringComparison.OrdinalIgnoreCase))
          FirstOrDefault();
    if(info == null) return DriveType.Unknown;
    return info.DriveType;
}

(You might want also take note of A.J.Bauer's answer: DriveInfo will also list USB HDs as DriveType.fixed)

回答3:

DriveInfo will also list USB HDs as DriveType.fixed, so this doesn't help if you need to know if a drive's interface is USB or not. Here is a VB.NET function that returns all external USB drive letters:

Imports System.Management

Public Shared Function GetExternalUSBDriveLettersCommaSeparated() As String
    Dim usbDrivesString As String = ""

    Dim wmiDiskDriveDeviceID As String = ""
    Dim wmiDiskDriveMediaType As String = ""
    Dim wmiDiskPartitionDeviceID As String = ""
    Dim wmiLogicalDiskDeviceID As String = ""

    Using wmiDiskDrives = New ManagementObjectSearcher("SELECT * FROM Win32_DiskDrive WHERE InterfaceType='USB'")
        For Each wmiDiskDrive As ManagementObject In wmiDiskDrives.Get
            wmiDiskDriveDeviceID = wmiDiskDrive("DeviceID").ToString
            wmiDiskDriveMediaType = wmiDiskDrive("MediaType").ToString.ToLower
            If wmiDiskDriveMediaType.Contains("external") Then
                Using wmiDiskPartitions = New ManagementObjectSearcher("ASSOCIATORS OF {Win32_DiskDrive.DeviceID='" + wmiDiskDriveDeviceID + "'} WHERE AssocClass = Win32_DiskDriveToDiskPartition")
                    For Each wmiDiskPartition As ManagementObject In wmiDiskPartitions.Get
                        wmiDiskPartitionDeviceID = wmiDiskPartition("DeviceID").ToString
                        Using wmiLogicalDisks = New ManagementObjectSearcher("ASSOCIATORS OF {Win32_DiskPartition.DeviceID='" + wmiDiskPartitionDeviceID + "'} WHERE AssocClass = Win32_LogicalDiskToPartition")
                            For Each wmiLogicalDisk As ManagementObject In wmiLogicalDisks.Get
                                wmiLogicalDiskDeviceID = wmiLogicalDisk("DeviceID").ToString
                                If usbDrivesString = "" Then
                                    usbDrivesString = wmiLogicalDiskDeviceID
                                Else
                                    usbDrivesString += "," + wmiLogicalDiskDeviceID
                                End If
                            Next
                        End Using
                    Next
                End Using
            End If
        Next
    End Using

    Return usbDrivesString
End Function

See this MSDN link: WMI Tasks: Disks and File Systems

回答4:

Have a look at DriveInfo and DriveType

回答5:

DriveType shows SUBSTed drives also as DriveType.Fixed.

To check if a drive is substed I use the code How to determine if a directory path was SUBST'd.