مشكلة في اظهار alert dialog عند النقر على زر flutter

اقوم ببناء تطبيق flutter .... التطبيق يحوي على  صفحة لدفع المخالفات

اريد اضافة تاكيد للموافقة على الدفع عن طريق ال alert dialog  

استخدم الكود التالي لكن عند الضغط على الزر لا يظهر ال alert dialog

Container(
                decoration: decor,
                child: SingleChildScrollView(
                  child: Container(
                    child: Column(
                      children: [
                        ListTile(
                            subtitle: Text(
                          "Violations:",
                          style: TextStyle(
                              fontSize: 25, fontWeight: FontWeight.bold),
                        )),
                        if (numberOfVilotions == 0)
                          Viol('NO Violation Found', '')
                        else
                          Column(
                            children: [
                              for (int j = 0; j < numberOfVilotions; j++)
                                Container(
                                  padding: EdgeInsets.all(15),
                                  margin: EdgeInsets.all(5),
                                  decoration: BoxDecoration(
                                    color: Colors.white70,
                                    borderRadius:
                                        BorderRadius.all(Radius.circular(16.0)),
                                  ),
                                  child: Column(
                                    children: [
                                      Viol(
                                          "Type:", violationData[j]['typeofv']),
                                      Viol("Date:", violationData[j]['datev']),
                                      Viol("Fee:", violationData[j]['fee']),
                                      Viol("Num:", violationData[j]['vionum']),
                                      SizedBox(
                                        height: 10,
                                      ),
                                      FlatButton(
                                        onPressed: () {
                                          print('pay pressed');
                                          child: AlertDialog(
                                                backgroundColor: Colors.red,
                                                shape: borderRadius,
                                                title: Text(
                                                    'Pay The Violation'),
                                                content: Text('Are You Sure?'),
                                                actions: <Widget>[
                                                  FlatButton(
                                                    shape: borderRadius,
                                                    color: Color(0XFF4a707a),
                                                    child: Center(
                                                      child: Text(
                                                        "Yes",
                                                        style: TextStyle(
                                                          color: Colors.white,
                                                        ),
                                                      ),
                                                    ),
                                                    onPressed: () {
                                                      setState(() {
                                                        PayVio(int.parse(
                                                            violationData[j]
                                                            ['vionum']));
                                                      });
                                                    },
                                                  ),
                                                  SizedBox(
                                                    height: 5,
                                                  ),
                                                  FlatButton(
                                                    shape: borderRadius,
                                                    color: Color(0XFF4a707a),
                                                    child: Center(
                                                        child: Text(
                                                          "NO",
                                                          style: TextStyle(
                                                              color: Colors
                                                                  .white),
                                                        )),
                                                    onPressed: () {
                                                      setState(() {
                                                      });
                                                    },
                                                  )
                                                ],
                                              );
                                            }