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468 Day 12
You can toggle a database field’s visibility in a grid, determine what its valid values are, and
control whether it can be changed—all using the TField component.
Table 12.24 lists the key properties, Table 12.25 lists the key methods, and Table 12.26 lists
the key events for TField.
Table 12.24. TField key properties.
Property Description
Calculated Reflects whether a field is a calculated field.
TDataset Returns the TDataset to which this TField belongs.
EditMask Specifies an input mask that limits text typed into the control.
FieldName Specifies the associated database field name.
Lookup Reflects whether a field is a lookup field.
Value Returns the TField’s underlying data value as a variant.
Visible Determines whether the TField is visible (by default) in DBGrid
controls.
Table 12.25. TField key methods.
Method Function
Assign Copies the value in one field to another.
AssignValue Assigns a literal value to a TField.
Clear Empties a TField.
GetData Returns the data from a field in raw format.
SetData Assigns raw data to a field.
Table 12.26. TField key events.
Event Catalyst
OnChange Occurs when any modification is made to a TField.
OnValidate Occurs when a field’s value is changed.