C# 中 将 UBB 代码（BBC 代码）的转换成 Html 代码

直接贴代码了：

using System;
using System.Text.RegularExpressions;

namespace MvcUI.Extensions
{
public static class BBCodeUtils
{
/// <summary>
/// 替换一个字符串中换行符（一般为“\r\n”）成特定的字符串
/// </summary>
/// <param name="lines">当前字符串</param>
/// <param name="replacement">要替换成的字符串</param>
/// <returns></returns>
public static string ReplaceLineBreaks(this string lines, string replacement)
{
if (string.IsNullOrEmpty(lines))
{
return lines;
}
return lines.Replace(Environment.NewLine, replacement);
}

/// <summary>
/// 转换基本的 BBCode 代码到 HTML
/// </summary>
/// <param name="str">包含 BBCode 的字符串</param>
/// <returns></returns>
public static string ConvertBbCodeToHtml(this string str)
{
// As this is a BBEditor we need to replace line breaks
// or they won't show in the front end
str = ReplaceLineBreaks(str, "<br>");

// format the bold tags:
// becomes: <strong></strong>
var exp = new Regex(@"\[b\](.+?)\[/b\]");
str = exp.Replace(str, "<strong>$1</strong>");

// format the italic tags: 
// becomes: <em></em>
exp = new Regex(@"\[i\](.+?)\[/i\]");
str = exp.Replace(str, "<em>$1</em>");

// format the underline tags: 
// becomes: <u></u>
exp = new Regex(@"\[u\](.+?)\[/u\]");
str = exp.Replace(str, "<u>$1</u>");

// format the underline tags: [ul][/ul]
// becomes: <ul></ul>
exp = new Regex(@"\[ul\](.+?)\[/ul\]");
str = exp.Replace(str, "<ul>$1</ul>");

// format the underline tags: [ol][/ol]
// becomes: <ol></ol>
exp = new Regex(@"\[ol\](.+?)\[/ol\]");
str = exp.Replace(str, "<ol>$1</ol>");

// format the underline tags: [li][/li]
// becomes: <li></li>
exp = new Regex(@"\[li\](.+?)\[/li\]");
str = exp.Replace(str, "<li>$1</li>");

// format the code tags: [code]

// becomes: <pre></pre>
exp = new Regex(@"\[code\](.+?)\[/code\]");
str = exp.Replace(str, "<pre>$1</pre>");

// format the code tags:
// becomes: <blockquote></blockquote>
exp = new Regex(@"\[quote\](.+?)\[/quote\]");
str = exp.Replace(str, "<blockquote>$1</blockquote>");

// format the strike tags: [s][/s]
// becomes: <strike></strike>
exp = new Regex(@"\[s\](.+?)\[/s\]");
str = exp.Replace(str, "<strike>$1</strike>");

//### Before this replace links without http ###
str.Replace("// format the url tags: [url=www.website.com" target=_blank>my site
// becomes: <a href="www.website.com">my site</a>
exp = new Regex(@"\[url\=([^\]]+)\]([^\]]+)\[/url\]");
str = exp.Replace(str, "<a rel=\"nofollow\" href=\"$1\">$2</a>");

// format the img tags:
// becomes: <img src="www.website.com/img/image.jpeg" />
exp = new Regex(@"\[img\]([^\]]+)\[/img\]");
str = exp.Replace(str, "<img src=\"$1\" />");

// format img tags with alt: [img=www.website.com/img/image.jpeg]this is the alt text[/img]
// becomes: <img src="www.website.com/img/image.jpeg" alt="this is the alt text" />
exp = new Regex(@"\[img\=([^\]]+)\]([^\]]+)\[/img\]");
str = exp.Replace(str, "<img src=\"$1\" alt=\"$2\" />");

// format the size tags: [size=1.2][/size]
// becomes: <span style="font-size:1.2em;"></span>
exp = new Regex(@"\[size\=([^\]]+)\]([^\]]+)\[/size\]");
str = exp.Replace(str, "<span style=\"font-size:$1em;\">$2</span>");

return str;
}
}
}[/code]

谢谢浏览！