Welche Art von Laufwerk ist "NoRootDirectory" (System.IO.DriveType.NoRootDirectory)?

Question

In C# System.IO.DriveInfo hat die Eigenschaft DriveType.

System.IO.DriveType ist eine Enumeration:

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, 
} 

Ich vermute, dass dies ein Volumen ohne Laufwerksbuchstaben. Aber mit:

System.IO.DriveInfo.GetDrives(); 

nicht mein Volumen ohne Laufwerksbuchstabe.

Wird NoRootDirectory für jede andere Art von Volumes/Laufwerken verwendet oder zeigt System.IO.DriveInfo.GetDrives() sie einfach nicht?

Answer 1

System.IO.DriveType.NoRootDirectory scheint für "ist zur Laufwerksbuchstaben nicht verwendete" eine misleadingly Bezeichnung zu sein

Testcode für alle Antriebe: Alle nicht gefunden Antriebe haben den Typ 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()); 
} 

Ergebnis:

// 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 

ehemalige Beispiel (vor diesen Beitrag bearbeiten):

Aber: Dies ist nur ein Fall, in dem gefunden NoRootDirectory verwendet wird. Es beantwortet nicht die Frage, ob es andere Konstellationen gibt, wo es gezeigt wird.

Hier ist der Testcode:

// J:\ is an unused drive letter 
var xDummy1 = new System.IO.DriveInfo("J:\\"); 
Console.WriteLine(xDummy1.Name);      // result: J:\ 
Console.WriteLine(xDummy1.DriveType);     // result: NoRootDirectory 
Console.WriteLine(xDummy1.IsReady);      // result: False 
// Console.WriteLine(xDummy1.DriveFormat); // would throw an DriveNotFoundException 
Console.WriteLine(System.IO.Directory.Exists("j:\\")); // result: False 


// S:\ is an mapped drive to a currently not available share 
var xDummy2 = new System.IO.DriveInfo("S:\\");   
Console.WriteLine(xDummy2.Name);      // result: S:\ 
Console.WriteLine(xDummy2.DriveType);     // result: Network 
Console.WriteLine(xDummy2.IsReady);      // result: False 
// Console.WriteLine(xDummy2.DriveFormat); // would throw an IOException 
Console.WriteLine(System.IO.Directory.Exists("S:\\")); // result: False 

Ich habe einige weitere Kombinationen mit verwendet getestet, jedoch nicht mehr vorhanden Laufwerke, aber keiner von ihnen zurück NoRootDirectory.

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); 
}