动态生成lookup字段

var
  i: Integer;
begin
  //ADOQuery已打开
   //在数据集打开的情况下新增加一个字段
  with Self.ADOQuery1 do
  begin
    TDataSetDesigner.Create(Self.ADOQuery1);
    try
      Designer.BeginDesign;
      //Keep Old Field
      //保留旧的字段
      Designer.DataSet.Fields.Clear;
      for i := 0 to FieldDefList.Count - 1 do
      begin
        with FieldDefList.FieldDefs[i].CreateField(Self) do
        begin
          DisplayLabel := IntToStr(i);
        end;
      end;

      //Add New Field
      //增加新的字段
      with DB.DefaultFieldClasses[TFieldType(2)].Create(Self) do
      begin
        FieldKind := TFieldKind(1);
        FieldName := 'FieldName' + IntToStr(i + 1);
        Name := 'FieldName1' + IntToStr(i + 1);
        DataSet := Self.ADOQuery1;
      end;
      //用于做后续增加字段的标志
      DesignerData := 'Design';
    finally
      Designer.EndDesign;
      Designer.Free;
      Self.RefreshListBox;
    end;
  end;
end;