The ComboBox is an editor that allows users to select an item from a drop-down list.
The main ComboBox API members are listed below.
- Data – Specifies the data source that populates the editor’s list items.
- TextFieldName – Specifies the data source’s field that supplies text for items.
- Text – Specifies the editor’s text.
- TextChanged - Fires when the editor text was changed.
- SelectedItem – Specifies the drop-down list’s selected item.
- SelectedItemChanged – Fires when the selected item was changed.
The ComboBox component supports different size modes. To specify the component's size in code, use the SizeMode property. To apply different size modes, use the drop-down list in the demo card's header.
This demo illustrates how to bind the ComboBox to a list of complex business objects.
- Entire - The ComboBox loads the entire item list. Use this option for small item lists where scrolling should work instantly.
- Virtual - The ComboBox loads visible items only. Use this option to improve performance when the list contains to many items to load simultaneously.
The AllowUserInput property specifies whether users are allowed to input values into an editor's edit box. The following property values are available:
- true - A user can either select an item from the drop-down list or enter new values into the edit box (without the need to invoke the drop-down list).
- false - A user can only select an item from the drop-down list.
In this demo, the AllowUserInput property is set to true.
- Contains - The ComboBox filters list items that contain the search string and highlights matches.
- StartsWith - The ComboBox filters list items that begin with the search string and highlights matches.
- None - The ComboBox does not filter list items.
In this demo, the filter mode is set to Contains.
Use the DropDownWidthMode property to specify the width of a drop-down list.
- ContentOrEditorWidth (Default) - The list's width is equal to the width of the longest list item or the editor's width (whichever is larger).
- ContentWidth - The list's width is equal to the width of the longest list item.
- EditorWidth - The list's width is equal to the editor's width. List items are cut if they do not fit.
In this demo, ContentOrEditorWidth mode is used for both ComboBox components. To change the width of their drop-down lists, use the Drop Down Width Mode option below.
Set the ClearButtonDisplayMode property to Auto to display the Clear button when the ComboBox has a non-null value. Users can click this button to clear the editor's value (set it to null).
This demo shows how to populate the ComboBox with items based on the user selection in another ComboBox.