Stringgrid check only one checkbox in a Column

[Hansvb]

Hi,

In a StringGrid I have a checkbox column. I want only 1 checkbox to be checked int this column. So if you check 1 and then want to check another checkbox in the same column, this should not be possible (until you have unchecked the first).
where to start with this?

[morknot]

A clumsy way but may help..

Code: Pascal  [Select][+][-]

1. procedure TForm1.StringGrid1CheckboxToggled(sender: TObject; aCol,
2.   aRow: Integer; aState: TCheckboxState);
3. var
4.   r:integer;
5.  
6. begin
7.  
8.  For r:=1 to arow-1 do
9.  StringGrid1.Cells[acol,r]:='0';
10.  For r:=arow+1 to stringgrid1.RowCount-1 do
11.  StringGrid1.Cells[acol,r]:='0';
12.  
13.  end;      
14.  
15.  

[Hansvb]

The approach wasn't good and I'm going to take it differently. In the prepare canvas I check if there are 2 checkmarks in the same column and then color the row red and then turn off the save button. That is workable for me.

[jamie]

Use the "OnCheckBoxState" event.

All rows will report, you just uncheck the other rows you don't want checked.

[Hansvb]

I don't understand it at all... See example. 3 string grids, each with a checkbox column.
What I want is that if you put 1 check mark in 1 checkbox, the cell will turn yellow (works). If you check 2 cells, they should turn red. I can only do that within 1 stringgrid. However, I want only 1 check mark to be enabled in the 3 string grids together. So if a checkbox is checked in 1 stringgrid and you check a checkbox in another stringgrid, both checkboxes should turn red. And if you uncheck 1, the only remaining one should be yellow again.

Is that possible?

[wp]

Can't you iterate over all three grids in the OnCheckboxToggled handler? The event's Sender tells you the grid, in which the click occured, and your CheckedCells array contains information in which one of the three grids the checked cells are located.

[Hansvb]

How can I adjust the color from OnCheckboxToggled ? I can't see that.

I've got it. The code is still very ugly, but it already works.
@wp, you put me on the right track.

[Hansvb]

It has improved a bit. This will be my practice project to understand stringgrid preparecanvas. i Slowly beginning to understand it.