update

lib/ui/favorite/favorite.dart

@@ -10,6 +10,7 @@ class Favorite extends StatefulWidget {
 
 class _FavoriteState extends State<Favorite> {
   bool checkBoxValue = false;
+  int a = 1;
 
   @override
   Widget build(BuildContext context) {
@@ -44,7 +45,7 @@ class _FavoriteState extends State<Favorite> {
                   ),
                   color: Color(0xFF3694A3),
                   child: Text(
-                    'ยืนยัน',
+                    'เพิ่มลงในตระกร้าของฉัน',
                     style: TextStyle(
                       fontSize: SizeConfig.getFontSize(16),
                       fontWeight: FontWeight.bold,
@@ -247,13 +248,17 @@ class _FavoriteState extends State<Favorite> {
                                                   child: Text('-'),
                                                   padding:
                                                       EdgeInsets.only(right: 0),
-                                                  onPressed: () {},
+                                                  onPressed: () {
+                                                    setState(() {
+                                                      a=a-1;
+                                                    });
+                                                  },
                                                 ),
                                               ),
                                               Padding(
                                                 padding: const EdgeInsets.only(
                                                     right: 8, left: 8),
-                                                child: Text('1'),
+                                                child: Text('$a'),
                                               ),
                                               SizedBox(
                                                 width: 20.0,
@@ -262,7 +267,9 @@ class _FavoriteState extends State<Favorite> {
                                                   child: Text('+'),
                                                   padding:
                                                       EdgeInsets.only(right: 0),
-                                                  onPressed: () {},
+                                                  onPressed: () {
+                                                    a=a+1;
+                                                  },
                                                 ),
                                               ),
                                             ],

lib/ui/payment/payment_page.dart

@@ -11,6 +11,9 @@ class Payment extends StatefulWidget {
 }
 
 class _PaymentState extends State<Payment> {
+
+  int a = 1;
+
   @override
   Widget build(BuildContext context) {
     SizeConfig(context);