C# で書き込みモードで開かれたファイルを読み取る ReadLines メソッド

TextFile.cs

using System.Collections.Generic;
using System.IO;
using System.Text;

/// <summary>
/// Provides iterators to read lines in a file.
/// </summary>
public static class TextFile
{
    /// <summary>
    /// Enumrates lines in the file with the file share setting.
    /// </summary>
    /// <param name="path"></param>
    /// <param name="fileShare"></param>
    /// <param name="encoding"></param>
    /// <returns></returns>
    public static IEnumerable<string> ReadLines(
        string path,
        FileShare fileShare = FileShare.ReadWrite,
        Encoding encoding = null)
    {
        using (var stream = new FileStream(path, FileMode.Open, FileAccess.Read, fileShare))
        using (var reader = new StreamReader(stream, encoding ?? Encoding.UTF8))
        {
            string line;
            while ((line = reader.ReadLine()) != null)
            {
                yield return line;
            }
        }
    }
}