Directory.Exists（）无法识别不存在的文件夹（反斜杠错误）

Question

I am using Directory.Exists() to check the existence of a folder, and encounter a failure of that method. My command is:

if (Directory.Exists(myFolder) == false) 
{ 
    MessageBox.Show(myFolder, "Invalid Log Folder path", MessageBoxButtons.OK, MessageBoxIcon.Hand); 
}

if (Directory.Exists(myFolder) == true) 
{ 
     MessageBox.Show(myFolder, "Valid Folder path"); 
}

When myFolder is C:\\Documents and Settings\\UserID\\My Documents it returns TRUE .

When myFolder is C:\\Documents and Settings\\xxx\\My Documents it returns FALSE (given that xxx does not exist).

However, when myFolder is C:\\\\Documents and Settings\\UserID\\My Documents it also returns TRUE .

The double backward slashes next to C: must have invalidated the test. However, Directory.Exists() fails to recognize that.

With more \\ it still encounters the same problem.

I just cannot understand how this failure occurs. I am using VS2008 with .NET 3.5.

Answer 1

Try this:

1. Open command prompt
2. enter the command cd c:\\\\\\\\\\\\\\\\\\

You will find it's perfectly acceptable.

Another test:

1. Open command prompt
2. try cd c:\\\\\\\\\\\\\\\\\\\\\\\\temp

You will now be in the c:\\temp directory, assuming you have one.

Last one:

1. Open command prompt
2. Try cd c:\\\\\\\\\\\\\\\\\\\\\\\\\\inetpub\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\logs

You are now in the c:\\inet\\logs directory, assuming you have one.

It seems you had incorrect expectations about how the Directory.Exists() method behaves.

Any number of '\\' is interpretted as a single '\\' in commands and those methods, and is perfectly acceptable input.