TcxCustomGridColumn Class

The base class for columns in Table and Banded Table grid Views.

Declaration

TcxCustomGridColumn = class(
    TcxCustomGridTableItem
)

Remarks

The TcxCustomGridColumn class implements core functionality common to all Table and Banded Table grid Views in all supported data access modes. A column displays data of the same type in a table. In bound and server data access modes, a column corresponds to an individual dataset field.

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.

Main API Members

The list below outlines key members of the TcxCustomGridColumn class. These members allow you to configure columns in Table and Banded Table grid Views.

General Appearance 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 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.

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.

Grid View-Related API Members

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.^[1]

Visible

Specifies if the column is visible.

Code Example: Create an Unbound Column and Configure Its In-Place Editor

The following code example creates an unbound Table View column, assigns an in-place spin editor to it, and limits the editor’s input value range:

Delphi

uses cxSpinEdit;
// ...
var
  AColumn: TcxGridColumn;
  ASpinEditProperties: TcxSpinEditProperties;
begin
  AColumn := cxGrid1TableView1.CreateColumn;  // Creates a new unbound column
  AColumn.DataBinding.ValueType := 'Currency'; // Changes the column value type to "Currency"
  AColumn.PropertiesClass := TcxSpinEditProperties; // Assigns an in-place spin editor
  ASpinEditProperties := AColumn.Properties as TcxSpinEditProperties;
  ASpinEditProperties.MinValue := 0;  // Sets the minimum edit value
  ASpinEditProperties.MaxValue := 1000; // Sets the maximum edit value
  ASpinEditProperties.Circular := True; // Loops value changes within the defined range
end;

C++

#include "cxSpinEdit.hpp"
// ...
  TcxGridColumn *AColumn;
  TcxSpinEditProperties *ASpinEditProperties;
  // ...
  AColumn = cxGrid1TableView1->CreateColumn(); // Creates a new unbound column
  AColumn->DataBinding->ValueType = "Currency"; // Changes the column value type to "Currency"
  AColumn->PropertiesClass = __classid(TcxSpinEditProperties); // Assigns an in-place spin editor
  ASpinEditProperties = dynamic_cast<TcxSpinEditProperties*>(AColumn->Properties);
  ASpinEditProperties->MinValue = 0;  // Sets the minimum edit value
  ASpinEditProperties->MaxValue = 1000; // Sets the maximum edit value
  ASpinEditProperties->Circular = true; // Loops value changes within the defined range

Grid Column Deletion

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

Delphi

  cxGrid1TableView1Column1.Free;

C++

  delete cxGrid1TableView1Column1;

Terminal TcxCustomGridColumn Class Descendants

Do not use the TcxCustomGridColumn class directly. Use the following descendants instead:

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.

TcxGridDBBandedColumn

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

Server Mode

TcxGridServerModeColumn

A column in a Server Mode grid Table View.

TcxGridServerModeBandedColumn

A column of a Banded Table View in Server Mode.

Inheritance

TObject

TPersistent

TComponent

TcxCustomComponent

TcxComponent

TcxCustomGridTableItem

TcxCustomGridColumn

Footnotes

1. All Server Mode Views do not support calculated field expressions because these Views load data on demand.

   A ShowExpressionEditor procedure call has no effect for simple and banded columns in Server Mode grid Views.