asp.net click to export excel (unicode support)

This sample query data from database and bind it to datagrid.
Datagrid will be exported to excel file in HTML steaming

Code in aspx.cs

protected void btnSubmit_Click(object sender, ImageClickEventArgs e)
{
DataGrid myDataGrid = new DataGrid();

System.Data.SqlClient.SqlConnection mysqlConnection;
System.Data.SqlClient.SqlCommand mysqlCommand;
System.Data.SqlClient.SqlDataReader dReader;

String queryString = @" TYPE IN YOUR SQL HERE ";

mysqlConnection = new SqlConnection(MyConstant.connectionString);
mysqlCommand = new System.Data.SqlClient.SqlCommand(queryString, mysqlConnection);

mysqlConnection.Open();

SqlDataAdapter da = new SqlDataAdapter(mysqlCommand);
DataSet ds = new DataSet();
da.Fill(ds);
myDataGrid.DataSource = ds.Tables[0];
myDataGrid.DataBind();

// convert the output fields to string format
String strStyle = "";
for (int intTemp = 0; intTemp < ds.Tables[0].Rows.Count; intTemp++)
{
for (int j = 0; j < myDataGrid.Items[intTemp].Cells.Count; j++) { myDataGrid.Items[intTemp].Cells[j].Attributes.Add("class", "text"); }
}

mysqlConnection.Close();

//export to excel
Response.Clear();
Response.Buffer = true;
Response.ContentType = "application/vnd.ms-excel"; Response.Charset = ""; Response.AddHeader("content-disposition", "attachment;filename=ExportExcel.xls"); Response.ContentEncoding = Encoding.Unicode;
Response.BinaryWrite(Encoding.Unicode.GetPreamble());

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