winform导出Excel文档

做了个winform下导出Excel文档的小示例：

 

private void btnExport_Click(object sender, EventArgs e)
        {
//grvOrderInfo 数据显示列表
 if (grvOrderInfo.Rows.Count < 1)
            {
                MessageBox.Show("无法进行导出，请确定您已经查询出数据！");
                return;
            }
SaveFileDialog saveFileDialog1 = new SaveFileDialog();
            //设置文件类型   
            saveFileDialog1.Filter = " xls files(*.xls)|*.xls";
            //设置默认文件类型显示顺序   
            saveFileDialog1.FilterIndex = 2;
            //保存对话框是否记忆上次打开的目录   
            saveFileDialog1.RestoreDirectory = true;
            //点了保存按钮进入   
            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                //获得文件路径   
                string localFilePath = saveFileDialog1.FileName.ToString();
                ExcelExport expt = new ExcelExport();
                expt.exportToExcel((DataTable)this.grvOrderInfo.DataSource, localFilePath);
            }
}