How to split() a delimited string to a List

I had this code:

    String[] lineElements;       
    . . .
    try
    {
        using (StreamReader sr = new StreamReader("TestFile.txt"))
        {
            String line;
            while ((line = sr.ReadLine()) != null)
            {
                lineElements = line.Split(',');
                . . .

but then thought I should maybe go with a List instead. But this code:

    List<String> listStrLineElements;
    . . .
    try
    {
        using (StreamReader sr = new StreamReader("TestFile.txt"))
        {
            String line;
            while ((line = sr.ReadLine()) != null)
            {
                listStrLineElements = line.Split(',');
. . .

…gives me, “Cannot implicitly convert type ‘string[]’ to ‘System.Collections.Generic.List’“