将多个文件合并为单个文件

Question

码:

static void MultipleFilesToSingleFile(string dirPath, string filePattern, string destFile)
{
    string[] fileAry = Directory.GetFiles(dirPath, filePattern);

    Console.WriteLine("Total File Count : " + fileAry.Length);

    using (TextWriter tw = new StreamWriter(destFile, true))
    {
        foreach (string filePath in fileAry)
        {
            using (TextReader tr = new StreamReader(filePath))
            {
                tw.WriteLine(tr.ReadToEnd());
                tr.Close();
                tr.Dispose();
            }
            Console.WriteLine("File Processed : " + filePath);
        }

        tw.Close();
        tw.Dispose();
    }
}

我需要优化它,因为它非常慢:平均大小为40 - 50 Mb XML文件的45个文件需要3分钟.

请注意:45个平均45 MB的文件只是一个例子,它可以是大小n的文件m数,其中n有数千个m,平均可以是128 Kb.简而言之,它可以变化.

您能否提供有关优化的任何观点？

Answer 1

为什么不直接使用该Stream.CopyTo()方法？

private static void CombineMultipleFilesIntoSingleFile(string inputDirectoryPath, string inputFileNamePattern, string outputFilePath)
{
    string[] inputFilePaths = Directory.GetFiles(inputDirectoryPath, inputFileNamePattern);
    Console.WriteLine("Number of files: {0}.", inputFilePaths.Length);
    using (var outputStream = File.Create(outputFilePath))
    {
        foreach (var inputFilePath in inputFilePaths)
        {
            using (var inputStream = File.OpenRead(inputFilePath))
            {
                // Buffer size can be passed as the second argument.
                inputStream.CopyTo(outputStream);
            }
            Console.WriteLine("The file {0} has been processed.", inputFilePath);
        }
    }
}