Button array disappears after click event

Question

Why do my buttons (array of buttons) disappear after I click any of them? Here is the code structure. Thanks a lot in advance.

public partial class Seatalloc2 :          


        

Answer 1

You must recreate dynamically created controls on every postback at the latest in Page_Load with the same ID as before to ensure that ViewState is loaded correctly and events are triggered. In your case with a static number of controls it's sufficient to call PopulateControls even on postbacks:

protected void Page_Load(object sender, EventArgs e)
{
   PopulateControls();
}

But you also need to add the Buttons to the Page's control-collection, for example to a Panel. Your array of buttons has no purpose:

protected void PopulateControls()
{
    for (int a = 0; a < 10; a++)
    for (int b = 0; b < 14; b++)
    {
        var btn = new Button();
        btn.ID = "Btn_" + a + "_" + b;
        // add an event handler for the click-event
        btn.Click += buttonHandler;
        MyButtonPanel.Controls.Add(btn);
    }
}