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TcxDBComboBox Class

vcl-cxdbedit-a5506109.md

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TcxDBComboBox Class

A data-aware combo box.

Declaration

delphi
TcxDBComboBox = class(
    TcxCustomComboBox
)

Remarks

A data-aware combo box allows you to display and edit values stored in a database. A combo box editor combines a single-line text editor and a drop-down menu. The drop-down menu displays a list of text strings accessible through the Properties.Items property. If user input in the text edit box matches initial characters in a menu string, the combo box allows a user to autocomplete the current input with the full string.

End-User Input Options

Up and Down arrow keys allow users to switch between combo box items, even when the drop-down menu is closed. Ctrl + Page Up and Ctrl + Page Down keystrokes select first and last items, respectively.

Drop-Down Menu Interaction

Users can do the following to open or close the drop-down combo box menu:

  • Click the drop-down button.
  • Focus the combo box and press the Alt + ↑ or Alt + ↓ key combination.
  • Focus the combo box and press the F4 key.

Note

You can invoke the drop-down menu only if it contains at least one value.

Main API Members

The list below outlines key members of the TcxComboBox class. These members allow you to configure combo boxes and manage combo box items.

Appearance and Behavior Settings

BeepOnEnterSpecifies if the combo box plays the default system sound when a user confirms input.Style | StyleDisabled | StyleFocused | StyleHot | StyleReadOnly

Allow you to define individual appearance settings for different editor states.

Tip

To apply the same style settings to multiple editors, use a TcxEditStyleController component. If you need to apply the same style settings to all editors in your application, you can use a TcxDefaultEditStyleController component.

StylesProvides access to individual styles applied to the combo box in different states.

Content-Related APIs

Clear | EditingValue | EditValue | EditingText | EditText | ResetEditValueManage the edit value.CopyToClipboard | CutToClipboard | PasteFromClipboardAllow you to perform clipboard operations.CanDropDown | DroppedDown | CloseUpManage the drop-down menu.ItemIndexSpecifies the active combo box item.OnEditingAllows you to prevent users from activating the combo box.PopupWindowAllows you to access and customize the drop-down menu.ResetEditValueRestores the previous edit value before the pending change is applied.SelectAllSelects editor content.SelStart | SelLength | SelText | SetSelection | SelectAll | ClearSelectionManage content selection.TextHintSpecifies a text hint for the combo box when it has no assigned edit value.UndoDiscards the last content change when the combo box has focus.ValidateEditValidates the display value.

Data-Related APIs

CanPostEditValueIdentifies if the data-aware combo box can post its edit value to the bound data storage.DataBindingAllows you to bind the combo box to data.OnPostEditValueExecutes custom code when the editor posts its value to the bound data storage.PostEditValuePosts the edit value to the bound data storage.

Combo Box Settings and Repository Items

ActivePropertiesProvides access to the current combo box settings regardless of their source. This property set does not allow you to customize combo box settings.GetPropertiesClassReturns the actual editor settings type.PropertiesAllows you to customize combo box settings directly if the combo box does not have an assigned repository item.RepositoryItemSpecifies a repository item as an external source of combo box settings. A repository item has priority over other combo box settings.

General-Purpose API Members

EnabledSpecifies if the combo box is enabled.CanModifyIdentifies if the combo box is in read-only mode.IsEditValidating | IsHiding | IsPostingAllow you to identify the current operation in the combo box.Width | HeightAllow you to explicitly define combo box dimensions.

Repository Item Class

You can create a TcxEditRepositoryComboBoxItem component in an edit repository to store combo box settings and share them between multiple combo boxes.

Limitations

The data-aware combo box is designed as a standalone editor. You cannot use a TcxDBComboBox class instance as an in-place editor in container controls.

Inheritance

Show 16 items

TObject TPersistent TComponent TControl TWinControl TCustomControl TcxCustomControl TcxControl TcxContainer TcxCustomEditContainer TcxCustomEdit TcxCustomTextEdit TcxCustomMaskEdit TcxCustomDropDownEdit TcxCustomComboBox TcxDBComboBox

See Also

TcxComboBox Class

TcxDBComboBox Members

cxDBEdit Unit