MatchCollection mc = Regex.Matches(yourStr,@"#([^#]+)#");
foreach(Match m in mc)
{
    //m.Groups[1].Value就是你要的
}

------解决方案--------------------
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C# code

MatchCollection mc = Regex.Matches(yourStr,@"#([^#]+)#");
foreach(Match m in mc)
{
    //m.Groups[1].Value就是你要的
}