asp.net DataGridView导出到Excel的三个方法

http://hi.baidu.com/%E5%EB%B3%DF%C8%CB%C9%FA/blog/item/58a1540bbf0bb437b1351d9a.html
#region DataGridView数据显示到Excel
/// <summary>
/// 打开Excel并将DataGridView控件中数据导出到Excel
/// </summary>
/// <param name="dgv">DataGridView对象 </param>
/// <param name="isShowExcle">是否显示Excel界面 </param>
/// <remarks>
/// add com "Microsoft Excel 11.0 Object Library"
/// using Excel=Microsoft.Office.Interop.Excel;
/// </remarks>
/// <returns> </returns>
public bool DataGridviewShowToExcel(DataGridView dgv, bool isShowExcle)
{
if (dgv.Rows.Count == 0)
return false;
//建立Excel对象
Excel.Application excel = new Excel.Application();
excel.Application.Workbooks.Add(true);
excel.Visible = isShowExcle;
//生成字段名称
for (int i = 0; i < dgv.ColumnCount; i++)
{
excel.Cells[1, i + 1] = dgv.Columns[i].HeaderText;
}
//填充数据
for (int i = 0; i < dgv.RowCount - 1; i++)
{
for (int j = 0; j < dgv.ColumnCount; j++)
{
if (dgv[j, i].ValueType == typeof(string))
{
excel.Cells[i + 2, j + 1] = "'" + dgv[j, i].Value.ToString();
}
else
{
excel.Cells[i + 2, j + 1] = dgv[j, i].Value.ToString();
}
}
}
return true;
}
#endregion
#region DateGridView导出到csv格式的Excel
/// <summary>
/// 常用方法，列之间加\t，一行一行输出，此文件其实是csv文件，不过默认可以当成Excel打开。
/// </summary>
/// <remarks>
/// using System.IO;
/// </remarks>
/// <param name="dgv"></param>
private void DataGridViewToExcel(DataGridView dgv)
{
SaveFileDialog dlg = new SaveFileDialog();
dlg.Filter = "Execl files (*.xls)|*.xls";
dlg.FilterIndex = 0;
dlg.RestoreDirectory = true;
dlg.CreatePrompt = true;
dlg.Title = "保存为Excel文件";
if (dlg.ShowDialog() == DialogResult.OK)
{
Stream myStream;
myStream = dlg.OpenFile();
StreamWriter sw = new StreamWriter(myStream, System.Text.Encoding.GetEncoding