DropDownList and the ViewState
I have no idea if I’m an idiot or not, but I did not know the DropDownList needs the viewstate to provide the SelectedValue.
Most of the time, I turn off viewstate for controls that hold large amounts of data. DataGrids are a good example. But also the DropDownList is a control that might hold larger amounts of data and all values and their keys are probable all inserted into the viewstate. Not something I’d want.
But when I had a problem with getting the selected item on postback of the webform, the member SelectedValue was always empty. I searched some sites, including Google, only to find this is not an unknown problem. The answer is pretty unknown, because no one can provide an answer.
I tried some colleagues at work, and one asked something about sessions state. This reminded me I had turned of the viewstate of my dropdownlist. Turned it on again, and it worked. Sigh.