Postback not updating bound listbox
They would otherwise be lost when a list is rebound to a database or other data source.
The approach most often taken is to have this database access occur only when the page is first loaded, and for this purpose you test to see whether the Helps the user work through very long (and unsorted) lists more quickly by allowing the user to start typing out the choice he wants from the list and highlighting the first option from the list that matches what he has typed controls, except that multiple list items are visible on the screen by default (with the aid of a vertical scroll bar if necessary), and multiple items can be selected from it at once (by changing the , and six items are displayed.
NET AJAX Extensions, which includes the Script Manager component, the Update Panel control, and the Update Progress control, and considers scenarios in which they should or should not be utilized.
When you run the page, you’ll see that a method runs every time the page is reloaded, but it’s often not a good idea to have all the code it contains be executed each time the method is run.
For instance, in many applications, the contents of lists and other controls are filled from a database, which can be an expensive operation.
The initial values for the dropdownlist in UC2 are populated in Page_Load of the ASPX page, and nothing is done to the dropdownlist in Page_Load (! I have found a couple of other forum posts out there that had the same problem but I've tried those resolutions and nothing has worked.
In the following examples, the value dt is the 'new' datatable that I wish to bind to the dropdown.