c# - 在 C# 中，如何在不破坏编码的情况下将网页保存到文件？

Question

这是我到目前为止得到的结果(这不起作用)。在这一点上，我认为我的目标是 Ansi 编码的，但我真的不想在这一点上知道。我的浏览器似乎能够确定要使用的编码，我该怎么做？

static void GetUrl(Uri uri, string localFileName)
{
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
    HttpWebResponse response;

    response = (HttpWebResponse)request.GetResponse();

    // Save the stream to file
    Stream responseStream = response.GetResponseStream();
    StreamReader reader = new StreamReader(responseStream, Encoding.Default);
    Stream fileStream = File.OpenWrite(localFileName);
    using (StreamWriter sw = new StreamWriter(fileStream, Encoding.Default))
    {
        sw.Write(reader.ReadToEnd());
        sw.Flush();
        sw.Close();
     }
}

---

回答后(目前仅在 UTF-8 网站上测试过):

static void GetUrl(Uri uri, string localFileName)
{
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
    try
    {
        // Hope GetEncoding() knows how to parse the CharacterSet
        Encoding encoding = Encoding.GetEncoding(response.CharacterSet);
        StreamReader reader = new StreamReader(response.GetResponseStream(), encoding);
        using (StreamWriter sw = new StreamWriter(localFileName, false, encoding))
        {
            sw.Write(reader.ReadToEnd());
            sw.Flush();
            sw.Close();
        }
    }
    finally
    {
        response.Close();
    }
}

Answer 1

网络浏览器通过三种方式尝试检测字符编码。

寻找(如果是 HTML):

<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">

或(对于 XHTML)

<?xml version="1.0" encoding="ISO-8859-1"?>

或者有时甚至在http header中指定

Content-Type: text/html; charset=ISO-8859-1