使用 FileStream 和 StreamWriter 时如何删除文件中最旧的行？

基于普拉卡什的回答here https://stackoverflow.com/questions/668907/how-to-delete-a-line-from-a-text-file-in-c，我想我应该尝试这样的方法来删除文件中最旧的行，然后再向其中添加新行：

private ExceptionLoggingService()
{
    _fileStream = File.OpenWrite(GetExecutionFolder() + "\\Application.log");
    _streamWriter = new StreamWriter(_fileStream);
}

public void WriteLog(string message)
{
    const int MAX_LINES_DESIRED = 1000;

    StringBuilder formattedMessage = new StringBuilder();
    formattedMessage.AppendLine("Date: " + DateTime.Now.ToString());
    formattedMessage.AppendLine("Message: " + message);

    // First, remove the earliest lines from the file if it's grown too much
    List<string> logList = File.ReadAllLines(_fileStream).ToList();
    while (logList.Count > MAX_LINES_DESIRED)
    {
        logList.RemoveAt(0);
    }
    File.WriteAllLines(_fileStream, logList.ToArray());

    _streamWriter.WriteLine(formattedMessage.ToString());
    _streamWriter.Flush();
}

...但是在我的.NET版本（Compact Framework，VS 2008中的Windows CE C#项目）中，ReadAllLines()和WriteAllLines()都不可用。

ReadAllLines/WriteAllLines 完成同样事情的挑战方法是什么？

UPDATE

这无疑是笨拙的，但看起来应该可行，我将对其进行测试。我将“缩短日志文件”代码从 WriteLog() 方法移至构造函数：

private ExceptionLoggingService()
{
    const int MAX_LINES_DESIRED = 1000;

    string uriPath = GetExecutionFolder() + "\\Application.log";
    string localPath = new Uri(uriPath).LocalPath;
    if (!File.Exists(localPath))
    {
        File.Create(localPath);
    }
    _fileStream = File.OpenWrite(localPath);
    // First, remove the earliest lines from the file if it's grown too much
    StreamReader reader = new StreamReader(_fileStream);
    List<String> logList = new List<String>();
    while (!reader.EndOfStream)
    {
        logList.Add(reader.ReadLine());
    }
    while (logList.Count > MAX_LINES_DESIRED)
    {
        logList.RemoveAt(0);
    }
    if (logList.Count > MAX_LINES_DESIRED)
    {
        _fileStream.Close();
        File.Delete(GetExecutionFolder() + "\\Application.log");
        File.Create(GetExecutionFolder() + "\\Application.log");
        _fileStream = File.OpenWrite(GetExecutionFolder() + "\\Application.log");
    }
    _streamWriter = new StreamWriter(_fileStream);
    foreach (String s in logList)
    {
        _streamWriter.WriteLine(s);
        _streamWriter.Flush();
    }
}

public void WriteLog(string message)
{
    StringBuilder formattedMessage = new StringBuilder();
    formattedMessage.AppendLine("Date: " + DateTime.Now.ToString());
    formattedMessage.AppendLine("Message: " + message);
    _streamWriter.WriteLine(formattedMessage.ToString());
    _streamWriter.Flush();
}

ReadAllLines and WriteAllLines只是对你隐藏了一个循环。做就是了：

StreamReader reader = new StreamReader(_fileStream);
List<String> logList = new List<String>();

while (!reader.EndOfStream)
   logList.Add(reader.ReadLine());

请注意，这与实施几乎相同File.ReadAllLines (from MSDN 参考源 http://referencesource.microsoft.com/#mscorlib/system/io/file.cs,675b2259e8706c26)

       String line;
        List<String> lines = new List<String>();

        using (StreamReader sr = new StreamReader(path, encoding))
            while ((line = sr.ReadLine()) != null)
                lines.Add(line);

        return lines.ToArray();

WriteAllLines很相似：

StreamWriter writer = new StreamWriter(path, false); //Don't append!
foreach (String line in logList)
{
   writer.WriteLine(line);
}