如何解码含有\x3c等Feedburner的结果 [英] How to decode Feedburner result containing \x3c and so on

问题描述

饲料刻录机改变了自己的博客服务返回结果，它返回一个类似的JavaScript块：

Feed burner changed their blog service return results that it returns blocks of javascript similar to:

的document.write（\x3cdiv
class\x3d\x22feedburnerFeedBlock\x22
id\x3d\x22RitterInsuranceMarketingRSSv3iugf6igask14fl8ok645b6l0\x22\x3e）;
的document.write（\x3cul\x3e）;
的document.write（\x3cli\x3e\x3cspan
class\x3d\x22headline\x22\x3e\x3ca
href\x3d\x22

document.write("\x3cdiv class\x3d\x22feedburnerFeedBlock\x22 id\x3d\x22RitterInsuranceMarketingRSSv3iugf6igask14fl8ok645b6l0\x22\x3e"); document.write("\x3cul\x3e"); document.write("\x3cli\x3e\x3cspan class\x3d\x22headline\x22\x3e\x3ca href\x3d\x22

我想原始HTML出于此。以前我能够轻松地只使用.Replace切割出的document.write语法，但我想不出有什么样的编码这个是或至少如何将它使用C＃解码

I want the raw html out of this. Previously I was able to easily just use .Replace to cleave out the document.write syntax but I can't figure out what kind of encoding this is or atleast how to decode it with C#.

编辑：嗯，这是一个半-nightmare终于解决了，这里就是我想出了柜面任何人有任何改进，以提供

Well this was a semi-nightmare to finally solve, here's what I came up with incase anyone has any improvements to offer

public static  char ConvertHexToASCII(this string hex)
{
    if (hex == null) throw new ArgumentNullException(hex);
    return (char)Convert.ToByte(hex, 16);
}

private string DecodeFeedburnerHtml(string html)
{
    var builder = new StringBuilder(html.Length);
    var stack = new Stack<char>(4);
    foreach (var chr in html)
    {
        switch (chr)
        {
            case '\\':
                if (stack.Count == 0)
                {
                    stack.Push(chr);
                }
                else
                {
                    stack.Clear();
                    builder.Append(chr);
                }
                break;
            case 'x':
                if (stack.Count == 1)
                {
                    stack.Push(chr);
                }
                else
                {
                    stack.Clear();
                    builder.Append(chr);
                }
                break;
            default:
                if (stack.Count >= 2)
                {
                    stack.Push(chr);

                    if (stack.Count == 4)
                    {
                        //get stack[3]stack[4]
                        string hexString = string.Format("{1}{0}", stack.Pop(),
                                                     stack.Pop());

                        builder.Append(hexString.ConvertHexToASCII());
                        stack.Clear();
                    }
                }
                else
                {
                    builder.Append(chr);
                }
                break;
        }
    }

    html = builder.ToString();
    return html;
}

不知道还有什么我可以做的更好。出于某种原因，这样的代码总是感觉真脏我，即使它是一个线性时间算法，我想这是关系到它多久会。

Not sure what else I could do better. For some reason code like this always feels really dirty to me even though it's a linear time algorithm I guess this is related to how long it has to be.

推荐答案

这些看起来像ASCII值，十六进制编码。你可以遍历字符串，每当你找到一个 \x 后跟两个十六进制数字（0-9，A-F），以及相应的ASCII字符替换它。如果字符串很长，这将是更快地逐步将结果保存到的的StringBuilder 而不是使用与string.replace（）。

Those look like ASCII values, encoded in hex. You could traverse the string, and whenever you find a \x followed by two hexadecimal digits (0-9,a-f), replace it with the corresponding ASCII character. If the string is long, it would be faster to save the result incrementally to a StringBuilder instead of using String.Replace().

不知的编码规范的，但有可能是更规则可循（例如，如果 \\ 是一个文字 \ ）。

I don't know the encoding specification, but there might be more rules to follow (for example, if \\ is an escape character for a literal \).

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