DataGird導出EXCEL的幾個方法（WebControl）
                                       



using System;
using System.Data;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Diagnostics;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.Collections;


namespace bookstore
{
 /// <summary>
 /// myExcel 的摘要說明。
 /// </summary>
 public class myExcel
 {
  public myExcel()
  {
            
  }


  /// <summary>
  /// 將DATAGRID導出為EXCEL文件方法一,
  /// 參數是:要導出的DATAGRID的ID和要保存下來的EXCEL文件名
  /// </summary>
  /// <param name="myPage">page</param>
  /// <param name="dg">datagrid</param>
  /// <param name="name">filename</param>   
  private void OutExcel(Page myPage,DataGrid dg,string name)
  {
   HttpResponse Response;  
   Response=myPage.Response;  

   string name1="attachment;filename="+name+".xls";  
   dg.Visible=true;
   Response.Clear(); 
   Response.Buffer= true; 
   Response.Charset="GB2312";
   
   Response.AppendHeader("Content-Disposition",name1);   

   Response.ContentEncoding=System.Text.Encoding.GetEncoding("GB2312");   
   Response.ContentType ="application/ms-excel";

   dg.EnableViewState = false;
   System.IO.StringWriter oStringWriter = new System.IO.StringWriter(); 
   System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
   dg.RenderControl(oHtmlTextWriter); 
   Response.Write(oStringWriter.ToString());
   Response.End();
  }


  /// <summary>
  /// 將DATAGRID導出為EXCEL文件方法二,
  /// 參數是:要導出的DATAGRID的ID和要保存下來的EXCEL文件名
  /// </summary>
  /// <param name="myPage">page</param>
  /// <param name="ctl">datagrid</param>
  /// <param name="filename">filename</param>
  public void ExportToExcel(Page myPage,DataGrid ctl,string filename) 
  { 
   HttpResponse Response;  
   Response=myPage.Response; 

   bool CurrCtlVisible=ctl.Visible;
   ctl.Visible=true;        
   Response.AppendHeader("Content-Disposition","attachment;filename="+filename+".xls");  
   Response.ContentEncoding = System.Text.Encoding.GetEncoding("utf-8");
   Response.ContentType = "application/ms-excel"; 
   ctl.Page.EnableViewState = false; 
   System.IO.StringWriter tw = new System.IO.StringWriter(); 
   System.Web.UI.HtmlTextWriter hw = new HtmlTextWriter(tw); 
   ctl.RenderControl(hw); 
   Response.Write(tw.ToString()); 
   Response.End(); 
            
   ctl.Page.EnableViewState = true; 
   ctl.Visible=CurrCtlVisible;
  }

  private void DgOutExcel(Page myPage,DataGrid dg,string name)
  {
   HttpResponse Response;  
   Response=myPage.Response;  

   string name1="attachment;filename="+name+".xls";  
   dg.Visible=true;
   Response.Clear(); 
   Response.Buffer= true; 
   Response.Charset="GB2312";
   
   Response.AppendHeader("Content-Disposition",name1);   

   Response.ContentEncoding=System.Text.Encoding.GetEncoding("GB2312");   
   Response.ContentType ="application/ms-excel";

   dg.EnableViewState = false;
   System.IO.StringWriter oStringWriter = new System.IO.StringWriter(); 
   System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
   dg.RenderControl(oHtmlTextWriter); 
   Response.Write(oStringWriter.ToString());
   Response.End();
  }


  #region   導出EXCEL，用DATASET

  public string myExportString(DataGrid DG,DataSet ds)
  {
   string  HTstring="<table><tr>";
   string Fieldstring="";
   ArrayList myAL=new ArrayList();
   string sRows="<tr>";
   for(int i=0;i<DG.Columns.Count;i++)
   {
    HTstring+="<td>"+DG.Columns[i].HeaderText+"</td>";
    Fieldstring+="<td>"+((System.Web.UI.WebControls.BoundColumn)(DG.Columns[i])).DataField+"</td>";
    myAL.Add(((System.Web.UI.WebControls.BoundColumn)(DG.Columns[i])).DataField);  
   }
                 
   for(int k=0;k<ds.Tables[0].Rows.Count;k++)
   {
    foreach(string field in myAL)
    {   
     sRows+= "<td>"+ds.Tables[0].Rows[k][field]+"</td>";
    }
    sRows+="</tr>";
   }       
   HTstring+="</tr>"+sRows+"</table>";

   return  HTstring;
  }


  public void SaveToExcel(Page myPage, string myExportString,string myFileName)
  {      
   HttpResponse resp;       
   resp=myPage.Response;
   resp.ContentEncoding=System.Text.Encoding.GetEncoding("GB2312");
   resp.AppendHeader("Content-Disposition","attachment;filename="+myFileName+".xls");
   resp.ContentType="application/ms-excel";                                                          
   resp.Write(myExportString);  
   resp.End();
   //resp.Clear();
   //resp.Close();     
  }


  public void Export(DataGrid myDG,DataTable dt,HttpResponse response)
  {
   // clean up response object
   response.Clear();
   response.Charset = "";
   response.Charset = "UTF-8";
   //   response.ContentEncoding = System.Text.Encoding.Default;
   response.ContentEncoding=System.Text.Encoding.GetEncoding("GB2312");  
   // set response object's mime type
   //   response.ContentType = "application/vnd.ms-excel"; 
   response.AppendHeader("Content-Disposition","attachment;filename=mytest.xls");
   System.IO.StringWriter sw = new System.IO.StringWriter();
   System.Web.UI.HtmlTextWriter htw = new System.Web.UI.HtmlTextWriter(sw);

   DataGrid dg = new DataGrid();
   dg.AllowPaging = false;
   dg.AllowSorting = false; 

   ArrayList myAL=new ArrayList();
   for(int i=0;i<myDG.Columns.Count;i++)
   {  
    // dg.Columns.AddAt(i,myDG.Columns[i]);
    // dg.Columns[i].HeaderText=myDG.Columns[i].HeaderText;   
    myAL.Add(((System.Web.UI.WebControls.BoundColumn)(myDG.Columns[i])).DataField);

    for(int k=0;k<dt.Columns.Count;k++)
    {
     foreach(string field in myAL)
     {
      if(dt.Columns[i].ColumnName==field)
      {
       dt.Columns[i].ColumnName=myDG.Columns[i].HeaderText; 
      } 
     }
    }       
   }  
   dg.DataSource = dt;
   dg.ShowHeader = true;
   dg.HeaderStyle.BackColor = System.Drawing.Color.DarkGray;
   dg.HeaderStyle.ForeColor = System.Drawing.Color.White;
   dg.HeaderStyle.Font.Bold = true;
   dg.AlternatingItemStyle.BackColor = System.Drawing.Color.LightGray;  
   dg.DataBind();  

   dg.RenderControl(htw);                                        
   response.Write(sw.ToString()); 
   response.End();
  }

  #endregion


 }
}