public void SaveExcel()
        {
            string fileSource = @"c:\1.xls"; //源文件
            using (SaveFileDialog saveFileDialog1 = new SaveFileDialog())
            {
                saveFileDialog1.Title = "另存为";
                saveFileDialog1.FileName = "newExcelName.xls"; //设置默认另存为的名字，可选
                saveFileDialog1.Filter = "Excel 文件(*.xls)|*.xls|Excel 文件(*.xlsx)|*.xlsx|所有文件(*.*)|*.*";
                saveFileDialog1.AddExtension = true;
                if (saveFileDialog1.ShowDialog() == DialogResult.OK)
                {
                    System.IO.File.Copy(fileSource, saveFileDialog1.FileName, true);
                }
            }
        }