The DropDownBox control provides a TextField and a list of predefined entries. The DropDownBox control is based on the ComboBox control. Additional features of the DropDownBox control are a history that shows the last-used entries; and the possibility to add a value help. Users can enter values in the text field that are provided by the list. During typing, a possible value is suggested using auto-completion.
The single items for the DropDownBox are added using the addItem
method.
The items are added to a ListBox control which also contains additional texts. The ListBox is referenced by the DropDownBox using the setListBox
method.
Using a ListBox for the DropDownBox allows a reuse of this ListBox in multiple DropDownBoxes. This is useful for tables, for example, where the possible values
are the same in every row.
The change
event is assigned to a function that fills the text field next to the DropDownBox. So you can see when the change
event is fired.
Control creation as well as property assignment in the following example are done using an alternative constructor syntax. The example also shows the history feature.
The items are filled via data binding. The data is bound to the properties using the bindProperty
method.
Changes on the data model directly change the DropDownBox content.
In this example, a search help is implemented using the Dialog control. The search must result in values available in the list.
The value of a DropdownBox can be set from the application using the properties value
, selectedKey
and
selectedItemId
. So instead of using the value
property the value can be set to an item of the Dropdownbox.
Additionally it can be determines which item is currently selected. If the properties selectedKey
and
selectedItemId
are set to an invalid value they will not be changed and still have their old value.
In the example you can see how to set and get the DropdownBox value using selectedKey
and selectedItemId
.