datagrid數據導入EXCEL的實現方法及注意事項

 實現方法，借鑑孟子老師的

private void Page_Load(object sender, System.EventArgs e)
        ...{
            // 在此處放置用戶代碼以初始化頁面
            if(Request .QueryString ["GenerateIndex"]!=null && Request .QueryString ["GenerateIndex"].ToString ()!="")
            ...{
                GenerateIndex=Convert .ToInt32 (Request .QueryString ["GenerateIndex"]);
            
            }
            if(!this.Page .IsPostBack )
            ...{
                
                DataTable dt=cpm.PaperGenerateDetailQuery (GenerateIndex);
                if(dt!=null && dt.Rows .Count >0)
                ...{
                    this.DataGrid1 .DataSource =dt;
                    this.DataGrid1 .DataBind ();
                }
            }
        }

private void Button1_Click(object sender, System.EventArgs e)
        ...{
            Response.Clear(); 
            Response.Buffer= true; 
            Response.Charset="GB2312";    
            Response.AppendHeader("Content-Disposition","attachment;filename=FileName.xls"); 
            Response.ContentEncoding=System.Text.Encoding.GetEncoding("GB2312");//設置輸出流爲簡體中文
            Response.ContentType = "application/ms-excel";//設置輸出文件類型爲excel文件。 
            this.EnableViewState = false;    
            System.Globalization.CultureInfo myCItrad = new System.Globalization.CultureInfo("ZH-CN",true);
            System.IO.StringWriter oStringWriter = new System.IO.StringWriter(myCItrad); 
            System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);            
            this.DataGrid1.RenderControl(oHtmlTextWriter); 
            Response.Write(oStringWriter.ToString());
            Response.End();
        }

        private void DataGrid1_ItemDataBound(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
        ...{
            if(e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
            ...{
                e.Item.Cells[0].Attributes.Add("style","vnd.ms-excel.numberformat:@");//格式化爲EXCEL的文本

                e.Item.Cells[1].Attributes.Add("style","vnd.ms-excel.numberformat:@");

            }
        }

注意：

1.若要使用此種方法，則datagrid不能做分頁操作，否則不能保存至EXCEL.

2.由於datagrid的數據量較大，共5萬條數據，生成的EXCEL文檔約爲6M。由於.net默認的request content 爲4096KB,約4M,因此將導致我此次的EXCEL生成失敗。解決辦法是，修改C:/WINDOWS/Microsoft.NET/Framework/v1.1.4322/CONFIG/machine.config文件，找到<httpRuntime
            executionTimeout="9000"
            maxRequestLength="4096"
            useFullyQualifiedRedirectUrl="false"
            minFreeThreads="20"
            minLocalRequestFreeThreads="20"
            appRequestQueueLimit="100"
            enableVersionHeader="true"
        />節，將maxRequestLength="4096"增大至409600.

至此，問題解決。