Response.Write and UpdatePanel

asp.net, httpresponse, response.write, updatepanel

Solution

You can't use `Response.Write` during an asynchronous postback. Whatever control executes that code needs to be added as a `PostBackTrigger` in the update panel:

<Triggers>        
    <asp:PostBackTrigger ControlID="Button1" />
</Triggers>

You can also do it in code-behind, if you prefer:

ScriptManager.GetCurrent().RegisterPostBackControl(Button1);

Problem

I generate a vcard that I send to the client using the following code snippet: ``` Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}", fileNameOnly)); Response.ContentType = "text/x-vcard"; Response.ContentEncoding = Encoding.GetEncoding("ISO-8859-1"); Response.Write(vCard.ToString()); Response.End(); ``` However, I need to use vCards on a page that has the control inside and UpdatePanel. Unfortunately, according to Update panel and Response write this does not work and causes an error. I am wondering what are some alternative ways to send the contents of the vcard/file to the client's browser and have it display "open/save" dialog that don't involve Response.Write?

Original source