TcxGridDBBandedColumn Class

A column in a data-aware Banded Table grid View.

Declaration

TcxGridDBBandedColumn = class(
    TcxGridBandedColumn
)

Remarks

A banded column displays data of the same type in a Banded Table View. You can group banded columns into bands that serve as common headers for grouped columns. A banded column can be visible only if it is associated with one of the bands in the parent Banded Table View.

VCL Data Grid: A Banded Table View Column Example

In-Place Editors

A column can use any unbound editor shipped with the ExpressEditors Library as an in-place editor for cell edit operations. An in-place editor instance exists (and, therefore, consumes memory and other system resources, such as a 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 available editors, you can use the PropertiesClassName or PropertiesClass property. Use the Properties property to configure the in-place editor associated with the column.

Default In-Place Editor and Data Types

When PropertiesClassName and PropertiesClass properties are unspecified, the data type of the underlying dataset field determines the active in-place editor according to the following table:

Dataset Field Type	Default In-Place Editor	Description
`ftBoolean`	TcxCheckBox	A check box editor with support for three states.
`ftCurrency`, `ftBCD`, and `ftFMTBcd`	TcxCurrencyEdit	A numeric editor for currency values.
`ftDate` and `ftDateTime`	TcxDateEdit	A date editor with a drop-down calendar.
`ftTime`	TcxTimeEdit	A spin editor for time values.
`ftBytes`, `ftVarBytes`, `ftBlob`, `ftFmtMemo`, `ftParadoxOle`, `ftDBaseOle`, and `ftTypedBinary`	TcxBlobEdit	A Binary Large Object (BLOB) editor.
`ftMemo`	TcxMemo	A multi-line editor for plain text.
`ftGraphic`	TcxImage	An editor designed to display images.
All other types	TcxMaskEdit	A single-line text editor with support for input masks.

Main API Members

The list below outlines key members of the TcxGridDBBandedColumn class. These members allow you to configure columns in data-aware Banded Table grid Views.

Appearance Customization Settings

ApplyBestFit | BestFitMaxWidth: Allow you to adjust the column width to display content in full and limit the maximum column width in this mode.
Caption | AlternateCaption: Specify main and alternative captions for the column. An alternative column caption can replace the main caption in customization dialogs, filter panels, etc.
HeaderGlyph | HeaderImageIndex: Allow you to assign a glyph to the column header.
OnCustomDrawCell: Allows you to override or complement column draw routines.
OnGetDisplayText | OnGetFilterDisplayText: Allow you to customize display text and column captions displayed in a filter drop-down window.
OnGetFilterImages | OnGetFilterValues: Allow you to customize the column’s filter drop-down window.

Styles: Allows you to customize the appearance of different banded column elements.

Column Layout Settings

FooterAlignmentHorz: Allows you to position column footer cells.
HeaderAlignmentHorz | HeaderAlignmentVert: Position the column header horizontally and vertically.
HeaderGlyphAlignmentHorz | HeaderGlyphAlignmentVert: Specify the glyph position within the column header.
LayoutItem | RowLayoutItem: Allow you to configure the column in a custom row layout.
MinWidth: Specifies the minimum column width, in pixels.

Position: Allows you to associate the column with a band in the parent Banded Table View.

Tip
Use the Position.BandIndex property to associate the column with an individual band. If the Position.BandIndex property is set to -1, the column is hidden.

In-Place Editor Settings

Editing: Specifies if the assigned in-place cell editor is active.
OnGetProperties: Allows you to display different in-place editors for different records or customize editor settings based on custom conditions.
OnGetPropertiesForEdit: Allows you to change the assigned in-place editor and customize its settings when a user invokes the editor.
Properties: Provides access to the settings of the assigned in-place editor.
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 column and configure the editor.
RepositoryItem: Allows you to associate the 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 grid View items or customize editor settings in OnGetProperties and OnGetPropertiesForEdit event handlers.

Data Management

DataBinding

Provides access to data binding settings.

GroupIndex: Allows you to group columns in the parent grid View by the current column.
SortIndex | SortOrder: Allow you to sort data in the parent grid View against the current column.

IsBottom | IsLeft | IsMostBottom | IsMostLeft | IsMostRight | IsRight | IsTop: Allow you to identify the column’s position within the parent grid View.
FixedKind: Allows you to fix the column or dock it to the left when users scroll the parent grid View to the right.
Focused: Specifies if the column has focus.
Index: Defines the column position in its parent grid View.
IsFirst | IsLast: Identify if the column is the first or last in the parent grid View’s collection of visible columns.
IsPreview: Allows you to identify if the column has a preview section.
MakeVisible: Scrolls the parent grid View to display the current column.
Selected: Identifies if the column is selected.
Summary: Provides access to column summary settings.
VisibleForEditForm | VisibleForRowLayout: Specify if the column is visible in an in-place Edit Form and the custom row layout.

General-Purpose API Members

Editable: Allows you to identify if the column is editable.
GridView: Provides access to the parent grid View.
Options: Allows you to configure general column settings.
RestoreDefaults: Restores the default values of column type-specific settings, such as Caption and Width.
ShowExpressionEditor: Invokes the Expression Editor dialog.
Visible: Specifies if the column is visible.

Banded Column Deletion

To delete a banded grid column, release it directly in code (call the Free procedure in Delphi or use the delete keyword in C++Builder):

Delphi
C++

  cxGrid1DBBandedTableView1Column1.Free;

  delete cxGrid1DBBandedTableView1Column1;

Direct TcxGridDBBandedColumn Class References

The following public API members reference a TcxGridDBBandedColumn object:

TcxGridDBBandedTableView.CreateColumn: Creates a column and adds it to the Columns collection of the data-aware Banded Table View, returning a pointer to the column created.
TcxGridDBBandedTableView.Columns: Provides indexed access to the collection of columns within the data-aware Banded Table View.

Other Grid Column Classes

Unbound

TcxGridColumn: A column in an unbound grid Table View.
TcxGridBandedColumn: A column in an unbound Banded Table View.

Data-Aware

TcxGridDBColumn: A column in a data-aware grid Table View.

Server Mode

TcxGridServerModeColumn: A column in a Server Mode grid Table View.
TcxGridServerModeBandedColumn: A column of a Banded Table View in Server Mode.

To see the Banded Table grid View in action, run the Grid and Data Editors demo in the VCL Demo Center installed with compiled DevExpress demos. Click the Banded View item in the side bar to the left.

Download: Compiled VCL Demos

Tip

You can find full source code for installed compiled Data Grid demos in the following folder:

%PUBLIC%\Public Documents\DevExpress VCL Demos\MegaDemos\Product Demos\ExpressQuantumGrid