Data.DB.TMemoField.Create
Delphi
constructor Create(AOwner: TComponent); override;
C++
__fastcall virtual TMemoField(System::Classes::TComponent* AOwner);
Properties
| Type | Visibility | Source | Unit | Parent |
|---|---|---|---|---|
| constructor | public | Data.DB.pas Data.DB.hpp |
Data.DB | TMemoField |
Description
Creates an instance of TMemoField.
Most applications do not explicitly create instances of TMemoField. Instead, the field components are created automatically, as persistent field components defined in the Fields editor at design time or as dynamic field components created automatically by the dataset.
Create sets the DataType property to ftMemo, and initializes the Transliterate property to true. The AOwner parameter specifies the component, typically a dataset, that becomes the new field's Owner. The Owner is responsible for freeing the component.
In the rare cases when you must create a persistent field component at runtime, call Create to create and initialize an instance of TMemoField. After instantiating a TMemoField, associate it with a specific field by setting its FieldName property to the name of the field. Give the TMemoField a unique identifier in the Name property. Establish where the field appears in the collection of fields by providing an ordinal number in the Index property. Associate the TMemoField with a dataset component by setting its DataSet property.
The example below creates a TMemoField object for a field named Notes accessed through a TQuery named Query1.
var
T: TMemoField;
begin
Query1.Close;
T := TMemoField.Create(Query1);
T.FieldName := 'Notes';
T.Name := Query1.Name + T.FieldName;
T.Index := Query1.FieldCount;
T.DataSet := Query1;
Query1.FieldDefs.UpDate;
Query1.Open;
end;
TMemoField *T;
Query1->Close();
T = new TMemoField(Query1);
T->FieldName = "Notes";
T->Name = Query1->Name + T->FieldName;
T->Index = Query1->FieldCount;
T->DataSet = Query1;
Query1->FieldDefs->UpDate();
Query1->Open();