Directory.Exists not working for a network path

问题:

I have a line of code checking if a directory exists and then getting the list of files in it.

System.IO.Directory.Exists(@"\\Server\Folder\");

I works when I test it (run from visual studio), but when I deploy the web site, it always returns false.

I do the same verification for another folder, on another server (let's say Server2) and it works fine.

I then thought it was an access issue, but the shared folder and network have all access to everyone... Is there another reason why it would not work?

回答1:

When you run the code in Visual Studio it runs under the the rights of your user.

When you run the code in IIS it runs in the identity of the Application Pool which by default is the built in user "Network Service" this is a local user account which does not have access outside the local machine.

The rights on the network share are the first layer, after that the NTFS rights on the directory are checked.

You need to change the identity of the application pool to a domain user with the same rights as your user.

回答2:

I may be a little late, but i've found that there is a problem on this method of the Directory class. Instead i've used DirectoryInfo with impersonation this way:

new DirectoryInfo(path).Exists

This way you avoid the whole identity change problem, which was denied by our IT area.

I hope this helps somebody!

回答3:

For future references, this also works:

bool result = false;
try
{
    Directory.GetAccessControl(path);
    result = true;
}
catch (UnauthorizedAccessException)
{
    result = true;
}
catch
{
    result = false;
}

回答4:

I was was getting this error with code a UNC that looked like this:

@"\Server01\c$\Data\SubFolder"

I made an explicit share and got rid of the c$ and made it look like this:

@"\Server01\TheData\SubFolder"

and it started to work.

I am not 100% sure that is what fixed the permissions problem, but it started to work immediately after making that change.