Force download ASP.Net

Question

In ASP.Net (with C #), I am trying to create a .DAT file with clear text in it and send it to the browser and force download. I tried a few things, but I can't get it to work. In my aspx file there isImageButton

<asp:ImageButton ID="btnSave" runat="server" CausesValidation="False" ImageUrl="~/Images/Stages/Database/Save.png" OnClick="btnSave_OnClick" Width="26px" />

In the OnClick method, I am trying to create a file and send it to the browser.

protected void btnSave_OnClick(object sender, EventArgs e)
{
    string file = "test.dat";
    string fileName = "~\\Stages\\Broekx\\Databanken\\" + file;

    FileStream fs = new FileStream(MapPath(fileName), FileMode.Open);
    long cntBytes = new FileInfo(MapPath(fileName)).Length;
    byte[] byteArray = new byte[Convert.ToInt32(cntBytes)];
    fs.Read(byteArray, 0, Convert.ToInt32(cntBytes));
    fs.Close();

    ImageButton btnSave = (ImageButton)FormViewStagesDummy.FindControl("btnSave");
    btnSave.Visible = false;

    File.Delete(Server.MapPath(fileName));

    if (byteArray != null)
    {
        this.Response.Clear();
        this.Response.ContentType = "text/plain";
        this.Response.AddHeader("content-disposition", "attachment;filename=" + file);
        this.Response.BinaryWrite(byteArray);
        this.Response.End();
        this.Response.Flush();
        this.Response.Close();
    }
}

The test.dat file exists in the correct folder and must be deleted after reading it in bytes. I tried this without deleting the file, and this does not work either.

After clicking the btnSave button, the button should be hidden, so I set the Visible parameter to false.

I also tried it with the application content type / octet stream or with the PDF file and the content type "application / pdf", but nothing works. The page loads normally and the file does not load.

Answer 1

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this.Response.AddHeader("content-disposition", "attachment;filename=" + file);

?

? , ?

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File.Delete(Server.MapPath(fileName));

.

:

Response.TransmitFile( Server.MapPath(fileName) );
Response.End();

TransmitFile , IIS, ( IIS).   Response.End();

Answer 2

                Response.Clear();
                Response.ClearContent();
                Response.ClearHeaders();
                Response.ContentType = "text/plain";
                Response.AppendHeader("Content-Disposition", "attachment; filename = " + fileName);
                Response.TransmitFile(Server.MapPath("~/foldername/" + fileName));
                Response.End();