Split a comma separated string while removing whitespace and empty entries

Building on the answer from Anthony, this will convert it back to a comma delimited string as well:

valueString = string.Join(",", valueString.Split(',')
    .Select(x => x.Trim())
    .Where(x => !string.IsNullOrWhiteSpace(x))
    .ToArray())

Using Trim with StringSplitOptions.RemoveEmptyEntries doesn't work because " " isn't considered an empty entry. You need to do a normal split, then trim each item, then filter out the empty strings.

valueString.Split(',')
    .Select(x => x.Trim())
    .Where(x => !string.IsNullOrWhiteSpace(x))
    .ToArray();