You can add the ScrollView to a layout in the Designer.
But you cannot directly add Views onto the internal Panel of the ScrollView.
You can define another layout for the internal Panel of the ScrollView in the Designer, but you must load this layout in the code with ScrollView1.LoadLayout("PanelLayoutName").
Don't forget to set the height and width of the internal ScrollView Panel to the correct value with ScrollView1.ContentHeight = yyy and ScrollView 1.ContentWidth = xxx.