/// <summary>
/// Check if a directory is a child of the parent
/// </summary>
/// <param name="parent"></param>
/// <param name="child"></param>
/// <returns></returns>
public static bool IsSubDirectory(DirectoryInfo parent, DirectoryInfo child)
{
#region Sanity Check
if (null == parent)
{
throw new ArgumentNullException(nameof(parent));
}
if (null == child)
{
throw new ArgumentNullException(nameof(child));
}
#endregion
#region Fast Checks
// "c:\foo\bar" is a child of "c:\foo"
var pFullName = DirectoryInfoComparer.FullName(parent);
var cFullName = DirectoryInfoComparer.FullName(child);
// if the parent is longer than the child
// then it cannot posibly be a child.
if (pFullName.Length > cFullName.Length)
{
return(false);
}
// are they equal?
if (pFullName.Length == cFullName.Length)
{
return(Equals(parent, child));
}
// if the root paths are not the same... then don't do it.
if (string.Compare(Path.GetPathRoot(pFullName), Path.GetPathRoot(cFullName), StringComparison.OrdinalIgnoreCase) != 0)
{
return(false);
}
#endregion
// is the child a substring of the parent...
return(cFullName.ToUpper().Contains(pFullName.ToUpper()));
}
public void FullNameCaseAreKept(string given, string expected)
{
Assert.AreEqual(expected, DirectoryInfoComparer.FullName(new DirectoryInfo(given)));
}
public void FullNameIsProperlyChanged(string lhs, string rhs)
{
Assert.AreEqual(
DirectoryInfoComparer.FullName(new DirectoryInfo(lhs)), rhs);
}
public void FulleNameCannotBeNull()
{
Assert.Throws <ArgumentNullException>(() => DirectoryInfoComparer.FullName(null));
}
