how to add multiple link buttons dynamically when clicking on the button of upload controller?

Question

I have a file upload controller to ftp server. I wants to retrieve the file names of each uploaded file and wants to display it on the same page as a linkbutton. so that i wants to add linkbuttons dynamically to the page. i have done like this. but when uploading more than one file it replaces the previously added links and only shows the last added file as linkbutton.

  protected void UploadButton_Click(object sender, EventArgs e)
{
    string filename = Path.GetFileName(FileUploadControl.FileName);
    Session["f_name"] = filename;


    Panel1.Controls.Add(new LiteralControl("<div>"));
    LinkButton lb = new LinkButton();
    lb.Text = filename;
    lb.ID = filename;
    Session["lb_pdf"]=lb.Text;
    string pdf=(string)Session["lb_pdf"];
    Panel1.Controls.Add(lb);
    Panel1.Controls.Add(new LiteralControl("</div>"));
    lb.PostBackUrl = "Default2.aspx";

how can i add multiple linkbuttons dynamically? please help

Answer 1

You could use a List<string> instead of a single string:

List<string> allFiles = new List<string>();
if(Session["f_name"] != null)
    allFiles = (List<string>)Session["f_name"];
else
    Session["f_name"] = allFiles;

allFiles.Add(filename);

foreach(string fileName in allFiles)
{
    // now create the LinkButtons ...
}

Note that you have to recreate all dynamically created controls on every postback. So if you can postback from this page without using the UploadButton you should use Page_Init or Page_Load to recreate the old LinkButtons instead. Thats also the better place in the life-cycle.

See: TRULY UNDERSTANDING DYNAMIC CONTROLS (Adding Dynamic Controls to the Control Tree)