/// <summary>
/// Creates a junction point from the specified directory to the specified target directory.
/// </summary>
/// <remarks>
/// Only works on NTFS.
/// </remarks>
/// <param name = "junctionPoint">The junction point path</param>
/// <param name = "targetDir">The target directory</param>
/// <param name = "overwrite">If true overwrites an existing reparse point or empty directory</param>
/// <exception cref = "IOException">Thrown when the junction point could not be created or when
/// an existing directory was found and <paramref name = "overwrite" /> if false</exception>
public static void Create(Directory junctionPoint, string targetDir, bool overwrite)
{
//targetDir = Path.GetFullPath(targetDir);
if (junctionPoint.Exists())
{
if (!overwrite)
throw new IOException("Directory already exists and overwrite parameter is false.");
}
else
junctionPoint.Create();
using (var handle = OpenReparsePoint(junctionPoint.Path, EFileAccess.GenericWrite))
{
var targetDirBytes = Encoding.Unicode.GetBytes(NonInterpretedPathPrefix + Path.GetFullPath(targetDir));
var reparseDataBuffer = new REPARSE_DATA_BUFFER();
reparseDataBuffer.ReparseTag = IO_REPARSE_TAG_MOUNT_POINT;
reparseDataBuffer.ReparseDataLength = (ushort) (targetDirBytes.Length + 12);
reparseDataBuffer.SubstituteNameOffset = 0;
reparseDataBuffer.SubstituteNameLength = (ushort) targetDirBytes.Length;
reparseDataBuffer.PrintNameOffset = (ushort) (targetDirBytes.Length + 2);
reparseDataBuffer.PrintNameLength = 0;
reparseDataBuffer.PathBuffer = new byte[0x3ff0];
Array.Copy(targetDirBytes, reparseDataBuffer.PathBuffer, targetDirBytes.Length);
var inBufferSize = Marshal.SizeOf(reparseDataBuffer);
var inBuffer = Marshal.AllocHGlobal(inBufferSize);
try
{
Marshal.StructureToPtr(reparseDataBuffer, inBuffer, false);
int bytesReturned;
var result = DeviceIoControl(handle.DangerousGetHandle(), FSCTL_SET_REPARSE_POINT,
inBuffer, targetDirBytes.Length + 20, IntPtr.Zero, 0, out bytesReturned, IntPtr.Zero);
if (!result)
ThrowLastWin32Error("Unable to create junction point.");
}
finally
{
Marshal.FreeHGlobal(inBuffer);
}
}
}
