//获取 RadioGroup 项目名称
procedure TForm1.RadioGroup1Click(Sender: TObject);
begin
Text := RadioGroup1.Items[RadioGroup1.ItemIndex];
end;

//当点击 RadioGroup 中的第几个选项时...
procedure TForm1.RadioGroup1Click(Sender: TObject);
var
str: string;
begin
case RadioGroup1.ItemIndex of
0: str := 'one';
1: str := 'two';
2: str := 'three';
3: str := 'four';
end;

Text := str;
end;