Second path fragment must not be a drive or UNC name - Create Subdirectory Error

Question

I have an exception in the third line ofthis code "Second path fragment must not be a drive or UNC name"

DirectoryInfo labdi = new DirectoryInfo(Back.mainfolderpath + @"\news\l");
DirectoryInfo tld = new DirectoryInfo(labdi.FullName + @"\" + NorA.sn.labl[i]);
tld = labdi.CreateSubdirectory(labdi.FullName + @"\" + NorA.sn.labl[i] + @"\");

There is no useful way on the web. Thank You.:!

Answer 1

The solution is to not put the full file path in the argument.

You already have the path of the parent directory as the object, so you only need to list the new directory name as an argument.

tld = labdi.CreateSubdirectory(NorA.sn.labl[i]);

Answer 2

I ran into this one today and finally tracked it down.

The exception is trying to tell you that when a DirectoryInfo takes a path as an argument (e.g., CreateSubdirectory or GetFiles), it will object if the path argument contains the Root and throw this elusive exception.

So path arguments that contain "C:\" or "D:\" etc do not work. Armed with this context, the exception message actually makes a bit of sense.

In your code, you were using the FullName property and this string contains "C:\" or whatever the root is.

Given the age of the question, I should add c#, .NET 4.5, VS2013.

Answer 3

The easiest solution to this problem is to use the static version of the Directory and File methods. You do not have to remove the root doing it this way. You also do not need the DirectoryInfo or FileInfo objects, they are what giving you headaches

string someFile = @"C:\somefolder\somefile.txt";
string directory = Path.GetDirectoryName(someFile);

foreach(var file in Directory.GetFiles(directory))
{
   File.Delete(file);
}