如何从URL中获取数据并将其保存到C＃.NET中的二进制文件中，而不会出现编码问题？

Question

In C#.NET, I want to fetch data from an URL and save it to a file in binary.

Using HttpWebRequest/Streamreader to read into a string and saving using StreamWriter works fine with ASCII, but non-ASCII characters get mangled because the Systems thinks it has to worry about Encodings, encode to Unicode or from or whatever.

What is the easiest way to GET data from an URL and saving it to a file, binary, as-is?

// This code works, but for ASCII only
String url = "url...";
HttpWebRequest  request  = (HttpWebRequest)
WebRequest.Create(url);

// execute the request
HttpWebResponse response = (HttpWebResponse)
request.GetResponse();

// we will read data via the response stream
Stream ReceiveStream = response.GetResponseStream();
StreamReader readStream = new StreamReader( ReceiveStream );
string contents = readStream.ReadToEnd();

string filename = @"...";

// create a writer and open the file
TextWriter tw = new StreamWriter(filename);
tw.Write(contents.Substring(5));
tw.Close();

Answer 1

Minimalist answer:

using (WebClient client = new WebClient()) {
    client.DownloadFile(url, filePath);
}

Or in PowerShell (suggested in an anonymous edit):

[System.Net.WebClient]::WebClient
$client = New-Object System.Net.WebClient
$client.DownloadFile($URL, $Filename)

Answer 2

Just don't use any StreamReader or TextWriter. Save into a file with a raw FileStream.

String url = ...;
HttpWebRequest  request  = (HttpWebRequest) WebRequest.Create(url);

// execute the request
HttpWebResponse response = (HttpWebResponse) request.GetResponse();

// we will read data via the response stream
Stream ReceiveStream = response.GetResponseStream();

string filename = ...;

byte[] buffer = new byte[1024];
FileStream outFile = new FileStream(filename, FileMode.Create);

int bytesRead;
while((bytesRead = ReceiveStream.Read(buffer, 0, buffer.Length)) != 0)
    outFile.Write(buffer, 0, bytesRead);

// Or using statement instead
outFile.Close()

Answer 3

This is what I use:

sUrl = "http://your.com/xml.file.xml";
rssReader = new XmlTextReader(sUrl.ToString());
rssDoc = new XmlDocument();

WebRequest wrGETURL;
wrGETURL = WebRequest.Create(sUrl);

Stream objStream;
objStream = wrGETURL.GetResponse().GetResponseStream();
StreamReader objReader = new StreamReader(objStream, Encoding.UTF8);
WebResponse wr = wrGETURL.GetResponse();
Stream receiveStream = wr.GetResponseStream();
StreamReader reader = new StreamReader(receiveStream, Encoding.UTF8);
string content = reader.ReadToEnd();
XmlDocument content2 = new XmlDocument();

content2.LoadXml(content);
content2.Save("direct.xml");