TCheckBoxColumn represents a checkbox column that is bound to a field in a data source.
The checked state of the checkboxes are determiend by the bound data at
{@link setDataField DataField}. If {@link setReadOnly ReadOnly} is false,
TCheckBoxColumn will display an enabled checkbox provided the cells are
in edit mode. Otherwise, the checkboxes will be disabled to prevent from editting.
The checkbox control in the TCheckBoxColumn can be accessed by one of
the following two methods:
$datagridItem->CheckBoxColumnID->CheckBox
$datagridItem->CheckBoxColumnID->Controls[0]
The second method is possible because the checkbox control created within the
datagrid cell is the first child.