We have an update panel on the page that contains rows of controls. The user can add additional rows or remove existing ones using a button that performs an Ajax postback. If the user adds additional rows, the values of the RadComboBox remain and life is good. However, if the user removes a row, the combobox value is lost (the items are there, but the selected index is set to -1).
In stepping through the code, I can see that the values are indeed set after Page_Load and Page_PreRender, but when the page is finally displayed, the values have been removed.
I've searched high and low and it appears this is an issue others have experienced as well (http://www.telerik.com/forums/selectedvalue-lost-on-postback-in-dynamically-added-user-controls). Unfortunately, I can't bind the values in Page_Init (as suggested in the post) as I need information from ViewState that isn't available until Page_Load.
All other controls on the update panel retain their value; it's *only* the comboboxes that lose theirs.
Has anyone else experienced this lately and, if so, what was the workaround?
We're using Telerik 2014 Q2 in VS2015 (C#).
1 Answer, 1 is accepted
Indeed, in order to persist the viewstate of the controls from a UserContorl - it should be added at Page_Init. However, you mentioned that the problem only persists with the RadComboBox control. This is why, I would like to ask you to submit a support ticket, along with a runnable sample attached, so we could locally test the behavior and eventually suggest you a workaround.
On a side note, could you please test the behavior by replacing the RadComboBox with a RadDropDownList, which is almost similar control, but a bit simplified.
Regards,
Nencho
Telerik