C＃Webclient Stream从FTP下载文件到本地存储

Question

我一直在通过WebClient对象从FTP服务器下载文件.NET命名空间提供，然后通过BinaryWriter将字节写入实际文件。一切都很好。但是，现在，文件的大小已经大大增加，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。

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：

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());     
     } 
    } 
} 

我会谈论这种不正确/更好的方式/ etc？

Answer 1

您是否尝试过WebClient类的以下用法？

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); 
} 

如果你想使用自定义缓存大小，下载文件中明确：

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); 
     } 
    } 
}