Discussion Board for collaboration related to QlikView App Development.
As scott-phl said, you can set a trigger to do this. There is also another way.
1. Clear all selections
2. Make the selections you want
3. Using the drop down under the 'Clear' button, select 'Set Clear State'
Now, whenever the user hits the clear button the selections you made will automatically be applied
Maybe I miss understand what you looking for.
Let try this case
+Case1 : Lock ListBox
1. Select one value in List Box ==> Right Click on List Box ==> Properties ==> Check Always Select One Value
+Case2: If you have select any field value when open document
1. Setting ==> Document Properties Triggers ==> OnOpen ==> Follow below