I use the method in above link to implement cascading dropdown list. However I have two issues can not be fixed using the above method.
1. In the last combobox(in above link, it is the city combobox), I set postback = true. However after page postback, the selected value in each combobox is lost. How can I retrieve the selected value for each combobox? Especially for the last combobox?
2. If there is only one selection in combobox, how to disable dropdown function in the combobox . For example, in the above link, if I choose “Asia” in continent combobox, “china” in country combobox, the “Beijing” will be only one selection in city combobox. How to let “beiJing” display in city combobox directly and disable its dropdown function?
From my understanding, the above method is using web service to implement cascading dropdown function, therefore it is stateless even within a same page. I am not sure if issue #1 is related with the stateless feature.