c# webclient stream 从 ftp 下载文件到本地存储-百家乐凯发k8

问题描述

我一直通过 .net 命名空间提供的 webclient 对象从 ftp 服务器下载文件，然后通过 将字节写入实际文件>binarywriter.一切都很好.但是，现在文件的大小急剧增加，我担心内存限制，所以我想创建一个下载流，创建一个文件流，并从下载中逐行读取并写入文件.

i've been downloading files from an ftp server via the webclient object that the .net namespace provides and then write the bytes to a actual file via a binarywriter. all is good. however, now, the files have dramatically increased in size and i'm worried about memory constraints so i'd like to create a download stream, create an file stream, and line by line read from the download and write to the file.

我很紧张，因为我找不到一个很好的例子.这是我的最终结果:

i'm nervous since i couldn't find a nice example of this. here's my end result:

var request = new webclient();
// omitted code to add credentials, etc..
var downloadstream = new streamreader(request.openread(ftpfilepathuri.tostring()));
using (var writestream = file.open(tolocation, filemode.createnew))
{
    using (var writer = new streamwriter(writestream))
    {
        while (!downloadstream.endofstream)
        {
            writer.write(downloadstream.readline());                  
        }
    }
}

我会采用这种不正确/更好的方式/等等吗?

am i going about this incorrect/better way/etc?

推荐答案

webclient 类的以下用法你试过了吗?

have you tried the following usage of webclient class?

using (webclient webclient = new webclient())
{
    webclient.downloadfile("url", "filepath");
}

更新

using (var client = new webclient())
using (var stream = client.openread("..."))
using (var file = file.create("..."))
{
    stream.copyto(file);
}

如果您想使用自定义缓冲区大小明确下载文件:

if you want to download file explicitly using customized buffer size:

public static void downloadfile(uri address, string filepath)
{
    using (var client = new webclient())
    using (var stream = client.openread(address))
    using (var file = file.create(filepath))
    {
        var buffer = new byte[4096];
        int bytesreceived;
        while ((bytesreceived = stream.read(buffer, 0, buffer.length)) != 0)
        {
            file.write(buffer, 0, bytesreceived);
        }
    }
}