C#中HTML字符轉換函數

在ASP.Net中經常會從網面中取數據或更新網頁的顯示。因為HTML中有些特殊字符如<, >, &等，顯示實際值不一致，造成保存到數據庫再取出來時會不一樣。因此需要以下函數做轉換：

///<summary>
        ///替換html中的特殊字符
        ///</summary>
        ///<paramname="theString">需要進行替換的文本。</param>
        ///<returns>替換完的文本。</returns>
        public static string HtmlEncode(string theString)
        {
            theString=theString.Replace(">","&gt;");
            theString=theString.Replace("<","&lt;");
            theString=theString.Replace(" ","&nbsp;");
            theString=theString.Replace("\"","&quot;");
            theString = theString.Replace("\'", "&#39;");
            theString=theString.Replace("\n","<br/>");
            return theString;
        }

        ///<summary>
        ///恢復html中的特殊字符
        ///</summary>
        ///<paramname="theString">需要恢復的文本。</param>
        ///<returns>恢復好的文本。</returns>
        public static string HtmlDiscode(string theString)
        {
            theString=theString.Replace("&gt;",">");
            theString=theString.Replace("&lt;","<");
            theString=theString.Replace("&nbsp;"," ");
            theString=theString.Replace("&quot;","\"");
            theString = theString.Replace("&#39;", "\'");
            theString=theString.Replace("<br/>","\n");
            return theString;
        }