Author: Tomas Rutkauskas

How can I set single Items.Strings in RadioGroups to Enabled := True or Enabled := 
False ?

Answer:

Solve 1:

1   TControl(RadioGroup1.Components[0]).Enabled := false;
2   TControl(RadioGroup1.Components[1]).Enabled := true;



Solve 2:

This function allows you to modify TRadioButtons in a given RadioGroup. Of course 
you can modify this to search not for a caption but for an index:
3   
4   function ButtonOfGroup(rg: TRadioGroup; SearchCaption: string): TRadioButton;
5   var
6     i: Integer;
7   begin
8     Result := nil;
9     for i := 0 to rg.ComponentCount - 1 do
10      if (rg.Components[i] is TRadioButton) and
11        (CompareStr(TRadioButton(rg.Components[i]).Caption, SearchCaption) = 0) then
12      begin
13        Result := TRadioButton(rg.Components[i]);
14        Break;
15      end;
16  end;



Solve 3:

The following code shows how to disable or enable an individual radio button in a 
TRadioGroup component (the second radio button in this case). Note that the 
RadioGroup.Controls is a zero based array.
17  
18  procedure TForm1.Button1Click(Sender: TObject);
19  begin
20    TRadioButton(RadioGroup1.Controls[1]).Enabled := False;
21  end;