c# - 在 C# 中高效地读取-修改-写入文本文件

Question

 private void AlterFile(string fileName)
    {
        StringBuilder content = new StringBuilder();
        bool isAltered = false;
        lock (LockObj)
        {
            using (StreamReader reader = new StreamReader(fileName))
            {
                string currLine;
                currLine = reader.ReadLine();
                while (currLine != null)
                {
                    content.AppendLine(currLine);
                    if (currLine.Contains(KeywordToSearch))
                    {
                        isAltered = true;
                        //insert data in string builder to be inserted here
                    }
                    currLine = reader.ReadLine();
                }


            }
            if (isAltered)
            {
                using (StreamWriter writer = new StreamWriter(fileName))
                {
                    writer.WriteLine(content.ToString());
                }
            }
        }
    }

我想从磁盘读取一个文本文件，在中间插入几行，然后将文件写入磁盘。考虑到这个操作要在一个 for each 循环中调用大约 1000 个文件，我发现这种方法效率很低。有没有更好的解决方案。提前致谢。