TcxDBTreeListColumn Class

A data-aware Tree List column.

Declaration

delphi

TcxDBTreeListColumn = class(
    TcxTreeListColumn
)

Remarks

The TcxDBTreeListColumn class implements a tree list column in the bound data access mode.

In-Place Editors

A tree list column can use any editor shipped with the ExpressEditors Library as an in-place editor for cell edit operations. An in-place editor instance exists (and, therefore, has its own WinAPI handle) only when a column cell is being edited. Otherwise, the column displays a static editor image for resource usage optimization.

To switch between all available in-place editors, you can use the PropertiesClass property. Use the Properties property to configure the in-place editor associated with the column.

In-Place Editors and Repository Items

Alternatively, you can assign an edit repository item component to the RepositoryItem property and use the repository item to define the active in-place editor and customize its settings.

Note

If an edit repository item is assigned to the RepositoryItem property, Properties, PropertiesClass, and PropertiesClassName properties have no effect.

Multiple In-Place Editors in One Column

You can handle OnGetEditProperties and OnGetEditingProperties events to dynamically change the assigned in-place editor and its settings based on custom conditions.

Important

Do not change PropertiesClass, PropertiesClassName, and Properties property values directly in OnGetEditProperties and OnGetEditingProperties event handlers.

To change the active editor and modify its settings safely within these event handlers, use the RepositoryItem property and TcxEditRepositoryItem class descendants.

Main API Members

The list below outlines key members of the TcxDBTreeListColumn class that allow you to configure columns in a Tree List control.

Appearance Customization

ApplyBestFit | BestFitMaxWidth | DisplayWidth | IndentWidth | MinWidth | RestoreWidths | WidthDefine the required column width in different scenarios.CaptionSpecifies the column’s caption.OnGetDisplayTextAllows you to customize cell display text.OnGetFilterImages | OnGetFilterValuesAllow you to customize the tree list column’s filter drop-down window.StatusHintSpecifies a hint displayed in a status bar component when a user hovers the mouse pointer over the tree list column.StylesAllows you to change the appearance of different tree list column elements.

In-Place Editor Settings

EditingSpecifies if the assigned in-place cell editor is active.EditValueAllows you to access and modify the edited cell value.PropertiesAllows you to customize the settings of the assigned in-place editor.PropertiesValueProvides access to active in-place editor settings.PropertiesClassSpecifies the active in-place editor class. At design time, you can use the Properties node in the Object Inspector to assign an in-place editor to the tree list column and configure the editor.RepositoryItem

Allows you to associate the tree list column with a repository item that defines the required in-place editor and its settings.

Tip

Repository items are particularly useful if you need to share in-place editor settings between multiple tree list columns or customize editor settings in OnGetEditProperties and OnGetEditingProperties event handlers.

Data Management

DataBindingProvides access to data binding settings.DisplayTexts | ValuesProvide access to individual cell values and corresponding display text strings.SortIndex | SortOrderAllow you to sort data in the parent Tree List control against the current column.Summary | SummaryFooterAllow you to configure column summaries.

Tree List Control-Related API Members

FocusedAllows you to check if the tree list column has focus.ItemIndex | PositionDefine the column’s position in the parent Tree List control.IsLeft | IsRightIdentify if the column is the first or last in its band.IsPreviewSpecifies if the column is the data source for the preview section.ShowExpressionEditorInvokes the Expression Editor dialog.VisibleForExpressionEditorSpecifies if the column is visible in the Expression Editor dialog.

General-Purpose API Members

ActuallyVisibleAllows you to check if the column is currently visible in the Tree List control’s client area.OptionsAllows you to configure general tree list column settings.RestoreDefaultsRestores the default values of tree column settings.TreeListProvides access to the Tree List control to which the column belongs.VisibleSpecifies if the column is visible.

Direct TcxDBTreeListColumn Class References

The following public API members reference the TcxDBTreeListColumn class as a TcxTreeListColumn object:

TcxCustomTreeList.ColumnsProvides indexed access to all columns.TcxCustomTreeList.VisibleColumnsProvides indexed access to visible columns.

You need to cast the returned object to the TcxDBTreeListColumn class to access all public API members.

Inheritance

TObject TPersistent TComponent TcxCustomInplaceEditContainer TcxTreeListColumn TcxDBTreeListColumn