如何在C#中删除file1中存在于file2中的行

List<string> file1Lines = new List<string>();
List<string> file2Lines = new List<string>();

using (StreamReader reader = new StreamReader("file1.txt"))
{
    string line;
    while ((line = reader.ReadLine()) != null)
    {
        file1Lines.Add(line);
    }
}

using (StreamReader reader = new StreamReader("file2.txt"))
{
    string line;
    while ((line = reader.ReadLine()) != null)
    {
        file2Lines.Add(line);
    }
}

List<string> newFile1Lines = new List<string>();

foreach (string line in file1Lines)
{
    if (!file2Lines.Contains(line))
    {
        newFile1Lines.Add(line);
    }
}

using (StreamWriter writer = new StreamWriter("newFile1.txt"))
{
    foreach (string line in newFile1Lines)
    {
        writer.WriteLine(line);
    }
}