datalist 导出excel的一个错误，指点一下
Response.Clear();
Response.BufferOutput = true;
Response.Charset = "GB2312";
Response.AppendHeader("Content-Disposition", "attachment;filename=FileName.xls");
Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
Response.ContentType = "application/ms-excel";
this.EnableViewState = false;
//System.Globalization.CultureInfo myCItrad =new System.Globalization.CultureInfo("ZH-CN", true);myCItrad
StringWriter tw = new StringWriter();
HtmlTextWriter hw = new HtmlTextWriter(tw);
DataList3.RenderControl(hw );
Response.Write(tw.ToString());
Response.End();

错误是——“只能在执行 Render() 的过程中调用 RegisterForEventValidation；”

[解决办法]
protected void Button1_Click(object sender, EventArgs e)
{
Response.Clear();

Response.AddHeader("content-disposition",
"attachment;filename=FileName.xls");

Response.Charset = "";

// If you want the option to open the Excel file without saving than

// comment out the line below

// Response.Cache.SetCacheability(HttpCacheability.NoCache);

Response.ContentType = "application/vnd.xls";

System.IO.StringWriter stringWrite = new System.IO.StringWriter();

System.Web.UI.HtmlTextWriter htmlWrite =
new HtmlTextWriter(stringWrite);

// turn off paging
GridView1.AllowPaging = false;
BindData();


GridView1.RenderControl(htmlWrite);

Response.Write(stringWrite.ToString());

Response.End();

// turn the paging on again
GridView1.AllowPaging = true;
BindData();

}