how to dynamic to create the calc field in the virtua table??

[akiraiu]

as my topic.

[Paul]

Working with calculated fields in Virtual table is not different from BDE components. For example you can use next code:

Code: Select all

var
  cfld : TFloatField;

implementation
procedure TForm1.Button1Click(Sender: TObject);
begin
//Assume that all fields are added  to Fields list before.
  VirtualTable1.Close;
  cfld := TFloatField.Create(self);
  cfld.FieldName := 'CalcFld';
  cfld.Calculated := true;
  cfld.DataSet := VirtualTable1;
  VirtualTable1.Open;
end;

procedure TForm1.VirtualTable1CalcFields(DataSet: TDataSet);
begin
  cfld.Value := DataSet.FieldByName('EmpNo').AsInteger + DataSet.FieldByName('Sal').AsInteger;
end;

[akiraiu]

Thx thx~~~~