如何通过单击按钮生成新列表?
可以使用循环或类似的东西来完成吗?
List<List<Countries>> groups = [];
...
child: GestureDetector(
onTap: () {
setState(() {
int numberOfGroups = groups.length;
int nextGroup = numberOfGroups++;
String number = nextGroup.toString();
List<Countries> number = [];
groups.add(number);
});
},
这不起作用:(
试试这个:
List<List<Countries>> groups = [];
...
child: GestureDetector(
onTap: () {
setState(() {
int numberOfGroups = groups.length;
int nextGroup = numberOfGroups + 1;
List<Countries> newGroup = [];
groups.add(newGroup);
});
},
),