I'm trying to use an UpdatePanel in my ASP.NET application. Unfortunately, it seems that I can't do this if I am using Server.Transfer() in my application.
Modifying that component of the application is not possible - the architecture makes extensive use of Server.Transfer() - in essence, every page request goes through this method. Does any workaround exist for this issue exist? Having to do full-page postbacks is so unfashionable these days...
I've got it! Thank Og for strange foreign language blogs :)
To fix it, I can simply tell the ASP.NET AJAX client-side framework to direct the partial request directly at the real target of the Server.Transfer() call. I am quite scared of the possible side-effects (who knows what this skips - the infrastructure does have a purpose) but it seems to be working fine so far.
Here is the method that fixes the problem, called in my page's Load event:
///
/// Adds to the page a JavaScript that corrects the misbehavior of AJAX when a page is target of a Server.Transfer call.
///
protected void AjaxUrlBugCorrection()
{
string actualFile = Server.MapPath(AppRelativeVirtualPath);
string redirectFile = Server.MapPath(Context.Request.FilePath);
string baseSiteVirtualPath = HttpRuntime.AppDomainAppVirtualPath;
if (actualFile != redirectFile)
{
System.Text.StringBuilder sbJS = new System.Text.StringBuilder();
string actionUrl = string.Format("'{0}'", baseSiteVirtualPath + AppRelativeVirtualPath.Replace("~", String.Empty));
sbJS.Append("Sys.Application.add_load(function(){");
sbJS.Append(" var form = Sys.WebForms.PageRequestManager.getInstance()._form;");
sbJS.Append(" form._initialAction = " + actionUrl + ";");
sbJS.Append(" form.action = " + actionUrl + ";");
sbJS.Append("});");
ClientScript.RegisterStartupScript(this.GetType(), "CorrecaoAjax", sbJS.ToString(), true);
}
}