Data.DB.TBytesField.Create

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Delphi

constructor Create(AOwner: TComponent); override;

C++

__fastcall virtual TBytesField(System::Classes::TComponent* AOwner);

Properties

Type Visibility Source Unit Parent
constructor public
Data.DB.pas
Data.DB.hpp
Data.DB TBytesField

Description

Creates an instance of TBytesField.

Most applications do not explicitly create instances of TBytesField. 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 ftBytes. 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 TBytesField. After instantiating a TBytesField, associate it with a specific field by setting its FieldName property to the name of the field. Give the TBytesField 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 TBytesField with a dataset component by setting its DataSet property to the name of the dataset component.

The example below creates a TBytesField object for a field named BytesField accessed through a TSQLDataSet named SQLDataSet1.



var
T: TBytesField;
begin
SQLDataSet1.Close;
T := TBytesField.Create(SQLDataSet1);
T.FieldName := 'BytesField';
T.Name := SQLDataSet1.Name + T.FieldName;
T.Index := SQLDataSet1.FieldCount;
T.DataSet := SQLDataSet1;
SQLDataSet1.FieldDefs.UpDate;
SQLDataSet1.Open;
end;



SQLDataSet1->Close();
TBytesField *T = new TBytesField(SQLDataSet1);
T->FieldName = "BytesField";
T->Name = SQLDataSet1->Name + T->FieldName;
T->Index = SQLDataSet1->FieldCount;
T->DataSet = SQLDataSet1;
SQLDataSet1->FieldDefs->UpDate();
SQLDataSet1->Open();



See Also