internal static IEnumerable <Pidl> ConvertPidlEnumeration(Native.IEnumIDList pEnum)
{
List <Pidl> children = new List <Pidl>();
IntPtr pidl = IntPtr.Zero;
int count = 0;
// get the first value in the enumeration (the args in the native method signature are more "ref" rather than "out")
pEnum.Next(1, out pidl, out count);
// check and loop if value is valid
while (!IntPtr.Zero.Equals(pidl) && count == 1)
{
children.Add(new Pidl(pidl, true));
// reset counters (required, see note above)
pidl = IntPtr.Zero;
count = 0;
// get the next value in the enumeration
pEnum.Next(1, out pidl, out count);
}
return(children);
}
private IEnumerable <Pidl> EnumerateChildPidls(Native.SHCONTF flags)
{
if (!_isFolder)
{
throw new InvalidOperationException("Children can only be enumerated on a folder-type item.");
}
if (_shellFolder == null)
{
return(new Pidl[0]);
}
// Get the IEnumIDList interface pointer.
Native.IEnumIDList pEnum = null;
uint hRes = _shellFolder.EnumObjects(IntPtr.Zero, flags, out pEnum);
if (hRes != 0)
{
throw new Exception("IShellFolder::EnumObjects failed to enumerate child objects.", Marshal.GetExceptionForHR((int)hRes));
}
try
{
return(Pidl.ConvertPidlEnumeration(pEnum));
}
finally
{
// Free the interface pointer.
Marshal.ReleaseComObject(pEnum);
}
}
