<asp:GridView ID="GridViewData" runat="server" OnRowDataBound="GridViewData_RowDataBound">
            </asp:GridView>

 protected void GridViewData_RowDataBound(object sender, GridViewRowEventArgs e)
    {
//格式问题
        GridViewRow gvr = e.Row;
        for(int i=0;i<=gvr.Cells .Count -1;i++)
        {
            gvr.Cells[i].Attributes.Add("style", "vnd.ms-excel.numberformat:@");
        }

//对编码字符串解码
        if (e.Row.RowType == DataControlRowType.DataRow)
        {

            TableCellCollection cells = e.Row.Cells;

            foreach (TableCell cell in cells)
            {
                cell.Text = Server.HtmlDecode(cell.Text);
            }

        }
    }

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="WebHtmlTextBox.ascx.cs" Inherits="CommonDrops_WebHtmlTextBox" %>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Literal ID="Literal1" runat="server"></asp:Literal><asp:HiddenField ID="HiddenField1" runat="server" />

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class CommonDrops_WebHtmlTextBox : System.Web.UI.UserControl
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            this.Literal1.Text = ConvertHtmlBianMaByScript(this.TextBox1, this.HiddenField1);
        }
    }

    public void SetTextBox(Button button)
    {
        this.TextBox1.TextMode = TextBoxMode.MultiLine;
        button.OnClientClick = "return converthtml" + TextBox1.ID + "()";
    }

    public void SetTextBox(Button button,int iRow,bool isPixel,int iWidth)
    {
        this.TextBox1.TextMode = TextBoxMode.MultiLine;
        button.OnClientClick = "return converthtml" + TextBox1.ID + "()";

        if (isPixel)
        {
            this.TextBox1.Width = Unit.Pixel(iWidth);
        }
        else
        {
            this.TextBox1.Width = Unit.Percentage(iWidth);
        }
        this.TextBox1.Rows = iRow;
    }

    public TextBox _TextBox
    {
        get
        {
            return this.TextBox1;
        }
        set
        {
            this.TextBox1 = value;
            this.Literal1.Text = ConvertHtmlBianMaByScript(this.TextBox1, this.HiddenField1);
        }
    }


    public string _Value
    {
        get
        {
            string s = ConvertHtmlJieMaByCs(this.HiddenField1.Value);
            this.TextBox1.Text = s;
            return s;
        }
    }

    public string ConvertHtmlBianMaByScript(TextBox tb, HiddenField hid)
    {
        string script = string.Empty;
        script += "<script type=\"text/javascript\">";
        script += "function converthtml" + tb.ID + "()";
        script += "{";
        script += "var txt=document .getElementById (\"" + tb.ClientID + "\").value;";

        script += "txt=txt.replace(/</g,\"01^01\");";
        script += "txt=txt.replace(/>/g,\"02^02\");";
        script += "txt=txt.replace(/\"/g,\"03^03\");";
        script += "txt=txt.replace(/=/g,\"04^04\");";

        script += "txt=txt.replace(/ /g,\"11^11\");";
        script += "txt=txt.replace(/function/g,\"12^12\");";
        script += "txt=txt.replace(/;/g,\"13^13\");";
        script += "txt=txt.replace(/http/g,\"14^14\");";
        script += "txt=txt.replace(/{/g,\"15^15\");";
        script += "txt=txt.replace(/}/g,\"16^16\");";
        script += "txt=txt.replace(/:/g,\"17^17\");";
        script += "txt=txt.replace(/;/g,\"18^18\");";
        script += "txt=txt.replace(/script/g,\"19^19\");";
        //script += "alert(txt);";
        script += "document .getElementById (\"" + hid.ClientID + "\").value=txt;";
        script += "document .getElementById (\"" + tb.ClientID + "\").value=\"\";";
        script += "return true;";
        script += "}";
        script += "</script> ";
        return script;
    }

    public string ConvertHtmlJieMaByCs(object obj)
    {
        if (obj == null) return string.Empty;
        string script = obj.ToString();
        if (script == string.Empty) return string.Empty;
        script = script.Replace("01^01", "<");
        script = script.Replace("02^02", ">");
        script = script.Replace("03^03", "\"");
        script = script.Replace("04^04", "=");

        script = script.Replace("11^11", " ");
        script = script.Replace("12^12", "function");
        script = script.Replace("13^13", ";");
        script = script.Replace("14^14", "http");
        script = script.Replace("15^15", "{");
        script = script.Replace("16^16", "}");
        script = script.Replace("17^17", ":");
        script = script.Replace("18^18", ";");
        script = script.Replace("19^19", "script");
        return script;
    }

}