# Creating Panel Controls

List Box Controls |

List Box controls allow users to select items from a displayed list. By default, users make one selection from a preassigned list of items. A predefined Data Class can also be applied to a List Box control.

When creating a List Box control, the style of the List Box is determined by the List Box Type property. When a List Box Type is selected, the design properties to be specified for that particular style of List Box are displayed. See List Box Type.

The List Box types that are supported in NOMADS are:

List Box Type | Description | Example
Standard | Lists a single column of data, with no formatting options. A Drop Box uses a similar format. |
Formatted | Displays multiple data elements over multiple columns with formatting and color. |
List View | Displays a single element of data over multiple columns (optionally may include bitmaps). |
Report View | Displays multiple data elements in different columns (similar to a Formatted List Box) and allows column headings, sorting, bitmaps and other formatting attributes. |
Tree View | Displays data grouped into a tree-like structure that optionally may include + (plus) and - (minus) buttons to expand tree levels, dotted lines and State Indicators. |

## Creating a List Box

To draw a new List Box on your panel, select the List Box control tool from the Controls Toolbar. Hold down the left-mouse button and drag the mouse to create a rectangle to the desired size. Release the mouse button to create the new object.

A List Box control can also be created from a data class or a data dictionary element. See Data Class Controls and Data Element Controls.

For making other adjustments, see Modifying Objects.

A system popup menu consisting of extraction, search and print options can also be added to any Grid or List Box (except Tree Views). See List Box and Grid System Popup Menu.

Different functionality is available depending on the List Box Type. For example, a Standard List Box could allow users to input their own values if the Allow Variable Input attribute is set. To allow more than one selection in a List Box, select the Multiple Selections check box. To define the specific attributes for the new control, see List Box Type.

For information and examples on the use of dynamic data classes and dynamic control properties, see Dynamic Control Properties.

## Loading Data Elements

Once a List Box is created, it can be loaded using LIST_BOX LOAD syntax in your program code. Smart Controls can also be used to simplify this process by auto-loading data based on query definitions. Use the Auto Load property to set this feature (if activated).

You can programmatically retrieve or set a selected item in a List Box, using the variable with the same name as the control. See Accessing and Manipulating Controls.

## See Also

Variable List Box
LIST_BOX Directive