TcxDBTreeListColumn Class
A data-aware Tree List column.
Declaration
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 | Width
- Define the required column width in different scenarios.
- Caption
- Specifies the column’s caption.
- OnGetDisplayText
- Allows you to customize cell display text.
- OnGetFilterImages | OnGetFilterValues
- Allow you to customize the tree list column’s filter drop-down window.
- StatusHint
- Specifies a hint displayed in a status bar component when a user hovers the mouse pointer over the tree list column.
- Styles
- Allows you to change the appearance of different tree list column elements.
In-Place Editor Settings
- Editing
- Specifies if the assigned in-place cell editor is active.
- EditValue
- Allows you to access and modify the edited cell value.
- Properties
- Allows you to customize the settings of the assigned in-place editor.
- PropertiesValue
- Provides access to active in-place editor settings.
- PropertiesClass
- Specifies 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
- DataBinding
- Provides access to data binding settings.
- DisplayTexts | Values
- Provide access to individual cell values and corresponding display text strings.
- SortIndex | SortOrder
- Allow you to sort data in the parent Tree List control against the current column.
- Summary | SummaryFooter
- Allow you to configure column summaries.
Tree List Control-Related API Members
- Focused
- Allows you to check if the tree list column has focus.
- ItemIndex | Position
- Define the column’s position in the parent Tree List control.
- IsLeft | IsRight
- Identify if the column is the first or last in its band.
- IsPreview
- Specifies if the column is the data source for the preview section.
- ShowExpressionEditor
- Invokes the Expression Editor dialog.
- VisibleForExpressionEditor
- Specifies if the column is visible in the Expression Editor dialog.
General-Purpose API Members
- ActuallyVisible
- Allows you to check if the column is currently visible in the Tree List control’s client area.
- Options
- Allows you to configure general tree list column settings.
- RestoreDefaults
- Restores the default values of tree column settings.
- TreeList
- Provides access to the Tree List control to which the column belongs.
- Visible
- Specifies if the column is visible.
Direct TcxDBTreeListColumn Class References
The following public API members reference the TcxDBTreeListColumn class as a TcxTreeListColumn object:
- TcxCustomTreeList.Columns
- Provides indexed access to columns.
- TcxCustomTreeList.VisibleColumns
- Provides indexed access to visible columns.
You need to cast the returned object to the TcxDBTreeListColumn class to access all public API members.