GridView匯出至Excel(GridView Export To Excel)

參考文章：
export to excel from dataview
在CodeFile中取得控制項將輸出Clinet端的HTML內容
Solving GridView Export Paging Problems
解決GridView使用RenderControl取得HTML出現的問題
KB-About Event Validation of ASP.NET 2.0

方法一：

protected void Button1_Click(object sender, EventArgs e)
{
 Response.Clear();
 Response.AddHeader("content-disposition", "attachment; filename=FileName1.xls");
 Response.Charset = "";
 Response.ContentType = "application/vnd.xls";
 System.IO.StringWriter stringWrite = new System.IO.StringWriter();
 System.Web.UI.HtmlTextWriter htmlWrite =
 new HtmlTextWriter(stringWrite);
 GridView g = new GridView();
 g.DataSource = SqlDataSource1;
 g.DataBind();
 g.RenderControl(htmlWrite);
 Response.Write(stringWrite.ToString());
 Response.End();

}

方法二：

public override void VerifyRenderingInServerForm(Control control)
{

// Confirms that an HtmlForm control is rendered for
//the specified ASP.NET server control at run time.
//不加會有型別 'GridView' 的控制項 'GridView1' 必須置於有 runat=server 的表單標記之中的錯誤發生。
}

protected void ExporToExcel(object sender, EventArgs e)
{
 Response.Clear();

 Response.AddHeader("content-disposition",
 "attachment;filename=sdf.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 & sorting
 GridView1.AllowPaging = false;
 GridView1.AllowSorting = false;
 GridView1.DataBind();

 GridView1.RenderControl(htmlWrite);
 Response.Write(stringWrite.ToString());
 Response.End();

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

}

如果GridView的分頁如排序無事前關閉再匯出，會發生
RegisterForEventValidation 只能在 Render(); 期間呼叫
的錯誤發生，解決方法有2種

1、請在html加上EnableEventValidation="false"修改如下
<%@ Page Language="C#" EnableEventValidation="false" AutoEventWireup="true" CodeFile="1003.aspx.cs" Inherits="_1003_1003" %>(儘量別用此方法，原因點我)

2、

 // turn off paging & sorting
 //匯出前先將排序與分頁關閉
 GridView1.AllowPaging = false;
 GridView1.AllowSorting = false;
 GridView1.DataBind();

 GridView1.RenderControl(htmlWrite);
 Response.Write(stringWrite.ToString());
 Response.End();

 // turn the paging on again
 //匯出後再將排序與分頁開啟
 GridView1.AllowPaging = true;
 GridView1.AllowSorting = true;
 GridView1.DataBind();