SaveFileDialog怎样才能实现弹出保存

//实例化SaveFileDialog

SaveFileDialog saveFileDialog1 = new SaveFileDialog();

saveFileDialog1.Filter = "Excel 文件(*.xls)|*.xls|Excel 文件(*.xlsx)|*.xlsx|所有文件(*.*)|*.*";

//以文件“*.xls”导出，定义格式

if (saveFileDialog1.ShowDialog() == DialogResult.OK) //是否选择是

{

       string sFilePathName = saveFileDialog1.FileName; //文件名

       ImportDB importDB = new ImportDB();

       int num = importDB.ExportDB(sFilePathName.ToString()); //执行导入

       if (num != 0)

       {

               MessageBox.Show("数据导出成功！");

       }

}