Overview

Overview of TDataComboBoxEh control

TDataComboBoxEh component is designed to display and select a value from a list.

The components support two operating modes:

• Simple Dropdown List: A basic dropdown list for selecting items.
• Lookup List: A list that maps displayed values to underlying data keys.

Both modes can operate with or without data binding (using DataSource/DataField) (for TDataComboBoxEh).

List Item Sources

The dropdown list items can be sourced in two ways:

External List

To connect an external list of values, use the following property:

• ListSource: TComponent – Supports binding to a TDataSource or TDataSet object.

Built-in List

For manually defining values, use the following property:

• ListItems: TStrings – A collection of strings displayed in the dropdown list.

Data Binding

To link the component to a data source, use the following properties:

• DataSource: Specifies the data source.
• DataFieldName: Specifies the field name in the data source.

Configuration by Mode

• External List:
  • Simple List Mode: Populate the ListSource and ListFieldName properties.
  • Lookup Mode: Populate the ListSource, ListFieldName, and ListKeyFieldName properties.
• Built-in List:
  • Simple List Mode: Populate the ListItems property with strings to be displayed in the list.
  • Lookup Mode: Populate the ListItems property with strings in the format: Key|Displayed Value.