JS、C# 去除html标签

var str = "<span style="display:none;" mce_style="display:none;">This is test</span><img src=''></img><strong></strong><br/>";     
str = str.replace(/<[^>].*?>/g,"");     
alert(str);   

public string RemoveHtmlTag(string Str)
        {
            return Regex.Replace(Str, "<[^>]*>", " ");
        }
 string str=f_ZhengWen.Value.ToString().Substring(0, 200);
 NeiRongJianJie.Value=RemoveHtmlTag（str）;