ASP.NET正则实现表情替换为图片，如[hanx]替换为<img src="img/hanx.gif"/>

string pattern = @"\[/(\w+)\]";
string result = System.Text.RegularExpressions.Regex.Replace("owjfdsl聊天消息，表情[hanx]j1111lsjfs", pattern, "<img src='img/${1}.gif' />");
result 就是转换后的字符串。

另，附一个别处找来的，关键字正则替换的扩展方法：

public static class StringManipulation
{
    public static string PregReplace(string input, string[] pattern, string[] replacements)
    {
        if (replacements.Length != pattern.Length)
            throw new ArgumentException("Replacement and Pattern Arrays must be balanced");

        for (int i = 0; i < pattern.Length; i++)
        {
            input = Regex.Replace(input, pattern[i], replacements[i]);                
        }

        return input;
    }
}