请问：导出Excel后不能弹出保存对话框

[goodsun2]

string filepath = Server.MapPath("../excel/");
string filename = "BUG管理.xls";
string savefilename = getfilename(filename);
Excel.Application app = new Excel.Application();
Excel.WorkbookClass book;
book = (Excel.WorkbookClass)app.Workbooks.Open(filepath + filename);
Excel.Worksheet worksheet4 = (Excel.Worksheet)book.Worksheets[4];//声明sheet页对象
。。。。。
//保存文件到此路径
book.SaveCopyAs(filepath + savefilename);
book.Saved = true;
book.Close(System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value);
app.Quit();
//打开文件
Response.Redirect("../excel/" + savefilename);


使用以上代码导出excel，本来会弹出一个"保存"对话框。但是我把"保存"对话框下的一个选项前的勾去掉了(忘了是什么)，然后再导出excel时"保存"对话框
就不会弹出来了，而是直接在IE中打开导出的Excel,请问如何才能再弹出"保存"对话框？？

[mandula2007]

试试这个

book.SaveCopyAs(Server.MapPath(".") + "\\filename.xls");//保存Excel文件
book.Close(false,null,null);
book.Quit();
GC.Collect();

System.IO.FileInfo file = new System.IO.FileInfo(Server.MapPath(".") + "\\filename.xls");
Response.Clear();
Response.Buffer= true;
Response.Charset = "UTF-8";
Response.ContentEncoding = System.Text.Encoding.UTF8;
Response.AppendHeader("Content-Disposition","attachment;filename="+Server.UrlEncode(file.Name));
Response.AddHeader("Content-Length",file.Length.ToString());
Response.ContentType = "application/ms-excel";
Response.WriteFile(file.FullName);
Response.End();

[suyiming]

string filepath = Server.MapPath("../excel/");
string filename = "BUG管理.xls";
string savefilename = getfilename(filename);
Excel.Application app = new Excel.Application();
Excel.WorkbookClass book;
book = (Excel.WorkbookClass)app.Workbooks.Open(filepath + filename);
Excel.Worksheet worksheet4 = (Excel.Worksheet)book.Worksheets[4];//声明sheet页对象
。。。。。
//保存文件到此路径
book.SaveCopyAs(filepath + savefilename);
book.Saved = true;
book.Close(System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value);
app.Quit();
//打开文件
Response.Redirect("../excel/" + savefilename);
Response.End();