Question

I have a table in DB with information about some goods. Goods may be fillable, so we can add text to it. So I want to dynamically generate a list of checkboxes related to info in table and even some checkboxes must be with TEdit component to make a possibility to add text to this item. So how can I do it? What component should I use? I figure out that TTreeView is almost enough, but it doesn’t allow to “draw” TEdit near checkboxes. I’m using Delphi 2010. Thanks in advance! Hope for your help!

Answer 1

If I read your question correctly, you would like to create some controls on a form based on the contents of table. In the following example I have assumed you want to do this based on the contents of the current record in a TDBGrid, so you’ll have to adapt as needed.

The example assumes a form with a TDBGrid and a TPanel (Panel1) that will hold the controls created at run time.

The TDBGrid will be connected to a TDataSource component and that will be connected to some TDataSet descendant for the table/query with the information. The TDataSource has a OnDataChanged event. This event gets triggered when the data in a field changes or when the current record in the dataset changes. So you can use that to change the controls as the current record changes.

procedure TForm1.DataSource1DataChange(Sender: TObject; Field: TField);
var
  i: Integer;
  Chk: TCheckBox;
  Edit: TEdit;
begin
  // When the Field is assigned, the call is the result of a change in the field.
  // When the Field is unassigned, the call is the result of changing the current record.
  if Assigned(Field) then
    Exit;

  // Remove controls on panel
  for i := Panel1.ControlCount - 1 downto 0 do
    Panel1.Controls[i].Free;

  // Add controls on panel for current record
  if True then      // Replace this with condition based on contents of current record (if any!)
  begin
    Chk := TCheckBox.Create(Self);  // Set Owner, so it is freed when form is closed.
    Chk.Parent := Panel1;           // Set Parent, so the control is shown.
    Chk.Left := FLeftIndent;        // Create FLeftIndent as a member field of the form, set value in OnCreate.
    Chk.Top := FNextTop;            // Create FNextTop as a member field of the form.
    Inc(FNextTop, FSpacing);        // Create FSpacing as a member field of the form, set value in OnCreate.

    if True then    // Replace this with condition that dictates creation of Edit
    begin
      Edit := TEdit.Create(Self);
      Edit.Parent := Panel1;
      Edit.Left := Chk.Left + Chk.Width + FSpacing;
      Edit.Top := Chk.Top;          // Add offset as needed for proper alignment of CheckBox and Edit.
    end;
  end;
end;

Please note that if you do not have any other checkboxes or edits on the form, you will have to include the proper vcl units yourself. The easiest way to do that is to drop them on the form, save the form and then delete the controls again.