List<String> saatList = [
  "9:00-12:00",
  "12:00-15:00",
  "15:00-18:00",
  "18:00-21:00"
];
String seciliSaat = "9:00-12:00";

Widget saatSec() {
  return Container(
      height: 150,
      padding: EdgeInsets.only(left: 5,right: 5),
      child: GridView.builder(
        itemCount: saatList.length,
        gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
          crossAxisCount: 2,
          mainAxisExtent: 60, // yükseklik demek
        ),
        itemBuilder: (BuildContext contex, int index) {
          String data = saatList[index];

          return InkWell(
            onTap: (){
              setState(() {
                seciliSaat = data;
              });
            },
            child: Card(
              semanticContainer: true,
              clipBehavior: Clip.antiAliasWithSaveLayer,
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(10.0),
              ),
              elevation: 8,
              child: Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Container(
                    width: 20,
                    height: 20,
                    child: Radio(
                        // title: Text(data),
                        // contentPadding: EdgeInsets.all(0),
                        value: data,
                        groupValue: seciliSaat,
                        onChanged: (val) {
                          setState(() {
                            seciliSaat = val.toString();
                          });
                        }),
                  ),
                  SizedBox(width: 5,),
                  Container(
                      child: Text(
                    data,

                    style: TextStyle(fontWeight: FontWeight.bold,fontSize: 15),

                    textAlign: TextAlign.left,
                  ))
                ],
              ),
            ),
          );
        },
      ));
}