"NoRootDirectory " (System.IO.DriveType.NoRootDirectory) 是什么驱动器？

Question

在 C# 中 System.IO.DriveInfo 有属性 DriveType。

System.IO.DriveType 是一个枚举：

public enum DriveType
{
    Unknown = 0,
    //
    // Summary:
    //     The drive does not have a root directory.
    NoRootDirectory = 1,
    Removable = 2,
    Fixed = 3,
    Network = 4,
    CDRom = 5,
    Ram = 6,
}

我怀疑这是一个没有盘符的卷。但是使用：

System.IO.DriveInfo.GetDrives();

不列出没有驱动器盘符的卷。

NoRootDirectory 用于任何其他类型的卷/驱动器还是 System.IO.DriveInfo.GetDrives() 只是不显示它们？

Answer 1

System.IO.DriveType.NoRootDirectory 似乎是对“此驱动器号未使用”的误导性指定

所有驱动器的测试代码：所有未找到的驱动器的类型为 DriveType.NoRootDirectory

foreach (char driveLetter in "ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToArray())
{
    var driveInfo = new System.IO.DriveInfo(driveLetter.ToString() + ":\");

    if(System.IO.DriveInfo.GetDrives().FirstOrDefault(o => o.Name[0] == driveLetter) == null)
        Console.WriteLine("// Not found: " + driveInfo.Name + " has DriveType: " + driveInfo.DriveType.ToString());
    else
        Console.WriteLine("//     found: " + driveInfo.Name + " has DriveType: " + driveInfo.DriveType.ToString());
}

结果：

// Not found: A:\ has DriveType: NoRootDirectory
// Not found: B:\ has DriveType: NoRootDirectory
//     found: C:\ has DriveType: Fixed
//     found: D:\ has DriveType: CDRom
// Not found: E:\ has DriveType: NoRootDirectory
// Not found: F:\ has DriveType: NoRootDirectory
// Not found: G:\ has DriveType: NoRootDirectory
// Not found: H:\ has DriveType: NoRootDirectory
// Not found: I:\ has DriveType: NoRootDirectory
// Not found: J:\ has DriveType: NoRootDirectory
// Not found: K:\ has DriveType: NoRootDirectory
// Not found: L:\ has DriveType: NoRootDirectory
// Not found: M:\ has DriveType: NoRootDirectory
// Not found: N:\ has DriveType: NoRootDirectory
// Not found: O:\ has DriveType: NoRootDirectory
//     found: P:\ has DriveType: Network
// Not found: Q:\ has DriveType: NoRootDirectory
//     found: R:\ has DriveType: Network
//     found: S:\ has DriveType: Network
// Not found: T:\ has DriveType: NoRootDirectory
// Not found: U:\ has DriveType: NoRootDirectory
//     found: V:\ has DriveType: Network
//     found: W:\ has DriveType: Fixed
//     found: X:\ has DriveType: Network
//     found: Y:\ has DriveType: Network
//     found: Z:\ has DriveType: Network

Answer 2

//Check fixed local drive
string path= "C\MyFolder\myfile.txt";
string root = Path.GetPathRoot(path);

if (DriveInfo.GetDrives().FirstOrDefault(d => d.Name == root).DriveType == DriveType.Fixed)
{
    MessageBox.Show(root);
}

Answer 3

我知道它用于未分配的驱动器号。您当然不会通过 GetDrives 获得它们，但可以尝试 new System.IO.DriveInfo("B:").DriveType 之类的。它也可能用于未格式化的分区（或未知文件系统），但我不完全确定（在这种情况下你必须测试你是否得到 Unknown 或 NoRootDirectory）。为了完整起见，您还可以通过转至 HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\DOS Devices 并创建一个指向 \Device\Null 的驱动器 X: 来创建垃圾驱动器，然后查看您得到的结果。

其实documentation for the underlying WinAPI function GetDriveType更清楚一点。它说：

The root path is invalid; for example, there is no volume mounted at the specified path.

我会将“根路径无效”翻译为“内核路径 \DosDevices\X: 没有 resolve/link 到能够解析路径请求的有效文件系统目录对象 \."

可能这句话是由具有 Windows 内核知识的人写的。在这种情况下，我假设上面的“垃圾驱动器”也会给你这个值，以及任何未分配的驱动器号。

要更详细地了解我刚才提到的内容，如果您有兴趣，请查看 http://www.osronline.com/article.cfm%5eid=107.htm。

"NoRootDirectory " (System.IO.DriveType.NoRootDirectory) 是什么驱动器？

What kind of drive is "NoRootDirectory " (System.IO.DriveType.NoRootDirectory)?

c#

drive