Author: Tomas Rutkauskas

I want the following: A StringGrid with 1 column of buttons in it. The number of 
rows in the grid is not known at design time, so the buttons are created at runtime.

Answer:

TSpeedButton will work and you won't have to worry about the TabStop. The problem 
with using the Rect that comes in as a param, it doesn't hit all the cells in the 
column. So what you end up with is buttons displaying in the wrong cells. If it 
doesn't matter, then you're ok. But if it does, then you'll need to update the 
entire column for all the visible cells. Here's what I came up with:

1   { ... }
2   var
3     HelpButtons: array of TSpeedButton;
4   
5   procedure Form1.CreateTheButtons;
6   var
7     i: Integer;
8   begin
9     SetLength(HelpButtons, ParamGrid.RowCount - 1);
10    for i := 0 to ParamGrid.RowCount - 2 do
11    begin
12      HelpButtons[i] := TSpeedButton.Create(Self);
13      HelpButtons[i].Visible := False;
14      HelpButtons[i].Parent := ParamGrid;
15      HelpButtons[i].Caption := IntToStr(i) + ' ?';
16      HelpButtons[i].Width := 34;
17      HelpButtons[i].Height := 18;
18      HelpButtons[i].Tag := i;
19      HelpButtons[i].OnClick := ParamGridButtonClick;
20    end;
21    {Force the buttons to show}
22    ParamGrid.Refresh;
23  end;
24  
25  procedure TForm1.ParamGridDrawCell(Sender: TObject; ACol, ARow: Integer;
26    Rect: TRect; State: TGridDrawState);
27  
28    procedure UpdateTheColumn;
29    var
30      i: Integer;
31      R: TRect;
32    begin
33      for i := ParamGrid.TopRow to (ParamGrid.VisibleRowCount + ParamGrid.TopRow) do
34      begin
35        if i >= ParamGrid.RowCount then
36          Break;
37        R := ParamGrid.CellRect(2, i);
38        HelpButtons[i - 1].Top := R.Top;
39        HelpButtons[i - 1].Left := R.Left;
40        if not HelpButtons[i - 1].Visible then
41          HelpButtons[i - 1].Visible := True;
42      end;
43    end;
44  
45  begin
46    if Length(HelpButtons) = 0 then
47      Exit;
48    if not FRefresh then
49      Exit;
50    if ((ACol = 2) and (ARow > 0)) then
51    begin
52      UpdateTheColumn;
53    end;
54  end;
55  
56  procedure TForm1.ParamGridButtonClick(Sender: TObject);
57  begin
58    ShowMessage('Click ' + Sender.ClassName + ' ' + IntToStr(TControl(Sender).Tag));
59  end;