SaveFileDialog不起作用

我正在开发一个操作，创建一个excel文件，然后打开一个SaveFileDialog，允许客户端将其保存在他们的计算机中。

问题是，在本地，SaveFileDialog工作，但出现在我的浏览器窗口后面，这是一个问题…

然后，当我在服务器上发布它时，SaveFileDialog完全不起作用。我在Stackoverflow上读了一些关于这个的其他话题，但我仍然没有找到正确的答案…

对不起我的英语错误，我是法国人。下面是我的代码:

String path = string.Empty;
object misValue = System.Reflection.Missing.Value;
bool canExport = false;
Excel.Application app = new Excel.Application();
Excel.Workbook wb = app.Workbooks.Add(1);
Excel.Worksheet ws = (Excel.Worksheet)wb.Worksheets.get_Item(1);
Excel.Range rng = (Excel.Range)ws.get_Range("A1", "K1");
/** Excel File completion **/
/** ... **/
/** ... **/
    SaveFileDialog sfd = new SaveFileDialog();
    sfd.InitialDirectory = Environment.SpecialFolder.Personal.ToString();
    sfd.Filter = "Classeur Excel 2010 (*.xls)|*.xls";
    if (STAShowDialog(sfd) == DialogResult.OK)
    {
        path = sfd.FileName;
        if (System.IO.File.Exists(path))
        {
            try
            {
                System.IO.File.Delete(path);
                canExport = true;
            }
            catch
            {
                MessageBox.Show("Impossible d'écrire par-dessus ce fichier.");
                canExport = false;
            }
        }
        else
        {
            canExport = true;
        }
    }
    SaveExcelFile(canExport, wb, path, app, ws, misValue);
    return View();

现在我的函数:

public void SaveExcelFile(bool canExport, Excel.Workbook wb, String path, Excel.Application app, Excel.Worksheet ws, object misValue)
{
    if (canExport)
    {
        try
        {
            wb.SaveAs(path, Microsoft.Office.Interop.Excel.XlFileFormat.xlWorkbookNormal,
                          Type.Missing, Type.Missing, Type.Missing, Type.Missing, XlSaveAsAccessMode.xlExclusive,
                          XlSaveConflictResolution.xlLocalSessionChanges, Type.Missing, Type.Missing);

            wb.Close(true, misValue, misValue);
            app.Quit();
        }
        catch
        {
            MessageBox.Show("Problème durant l'exportation'r'n Code erreur #EX01");
        }
    }
    releaseObject(ws);
    releaseObject(wb);
    releaseObject(app);
}
private DialogResult STAShowDialog(FileDialog dialog)
{
    DialogState state = new DialogState();
    state.dialog = dialog;
    System.Threading.Thread t = new System.Threading.Thread(state.ThreadProcShowDialog) { IsBackground = true, Name = "threadExport", Priority = System.Threading.ThreadPriority.AboveNormal };
    t.SetApartmentState(System.Threading.ApartmentState.STA);
    t.Start();
    t.Join();
    return state.result;
}

<%@ WebHandler Language="C#" Class="Handler" %> 
using System; 
using System.Web; 
public class Handler : IHttpHandler { 
    public void ProcessRequest (HttpContext context) { 
        HttpResponse r = context.Response; 
        r.ContentType = "image/png"; 
        // 
        // Write the requested image 
        // 
        string file = context.Request.QueryString["file"]; 
// Get Data From Database. And write file. 
        if (file == "logo") 
        { 
            r.WriteFile("Logo1.png"); 
        } 
        else 
        { 
            r.WriteFile("Flower1.png"); 
        } 
    } 
    public bool IsReusable { 
        get { 
            return false; 
        } 
    } 
}