转换GridView的内容到Excel里面 ---带有格式

protected void Button1_Click(object sender, EventArgs e)
{
Response.Clear();
Response.Buffer = true;
Response.AddHeader("content-disposition", "attachment;filename=GridViewExport.xls");
Response.Charset = "";
Response.ContentType = "application/vnd.ms-excel";
using (StringWriter sw = new StringWriter())
{
HtmlTextWriter hw = new HtmlTextWriter(sw);

//To Export all pages
GridView1.AllowPaging = false;
this.BindGrid();

GridView1.HeaderRow.BackColor = Color.White;
foreach (TableCell cell in GridView1.HeaderRow.Cells)
{
cell.BackColor = GridView1.HeaderStyle.BackColor;
}
foreach (GridViewRow row in GridView1.Rows)
{
row.BackColor = Color.White;
foreach (TableCell cell in row.Cells)
{
if (row.RowIndex % 2 == 0)
{
cell.BackColor = GridView1.AlternatingRowStyle.BackColor;
}
else
{

cell.BackColor = GridView1.RowStyle.BackColor
}
cell.CssClass = "textmode";
}
}

GridView1.RenderControl(hw);
//style to format numbers to string
string style = @"<style> .textmode { } </style>";
Response.Write(style);
Response.Output.Write(sw.ToString());
Response.Flush();
Response.End();
}
}

public override void VerifyRenderingInServerForm(Control control)
{
/* Verifies that the control is rendered */
}