C# -- 使用缓冲区进行文件下载操作

痛定思痛。 2021-11-14 00:34 369阅读 0赞

C\# -- 使用缓冲区进行文件下载操作

1. 为避免下载超大文件占用内存资源，文件下载使用缓冲区，一点一点读取文件资源。

string str0 = @"ftp://localhost:21/xx/1.txt";
        string str1 = @"D:\2.txt";
    
        FtpWebRequest ftpWebRequest1 = (FtpWebRequest)WebRequest.Create(str0);
        ftpWebRequest1.KeepAlive = false;
        ftpWebRequest1.Method = WebRequestMethods.Ftp.GetFileSize;
        FtpWebResponse ftpWebResponse1 = (FtpWebResponse)ftpWebRequest1.GetResponse();
        long iContentLength1 = ftpWebResponse1.ContentLength;
        Console.WriteLine("FTP file content length:{0}字节", iContentLength1);
    
    
        FtpWebRequest ftpWebRequest2 = (FtpWebRequest)WebRequest.Create(str0);
        ftpWebRequest2.Method = WebRequestMethods.Ftp.DownloadFile;
        FtpWebResponse ftpWebResponse2 = (FtpWebResponse)ftpWebRequest2.GetResponse();
        Stream stream = ftpWebResponse2.GetResponseStream();
    
        FileStream fileStream = new FileStream(str1, FileMode.Create);
    
        int BufferSize = 2* 1024 * 1024;
        byte[] Buffer = new byte[BufferSize];
    
        int iRead = 0;
        iRead = stream.Read(Buffer, 0, BufferSize);
        while (iRead > 0)
        {
            fileStream.Write(Buffer, 0, iRead);
            iRead = stream.Read(Buffer, 0, BufferSize);
        }
    
     stream.Close();     fileStream.Close(); 
        FileInfo newFileInfo = new FileInfo(str1);
        long iContentLength2 = newFileInfo.Length;
        Console.WriteLine("Download file content lenth:{0}字节", iContentLength2);
        Console.WriteLine("文件校验：{0}", iContentLength1 == iContentLength2 ? "OK" : "文件大小不一样");

![1408130-20190723111935284-1612191844.jpg][]

转载于:https://www.cnblogs.com/ChengWenHao/p/CSharpDownloadFileUseBufferByte.html

[1408130-20190723111935284-1612191844.jpg]: /images/20211113/4cd7061bfb004b8da38ed76b24b71937.png