如何禁用下拉列表一旦用户选择了下拉列表中的项目在扑动

Question

我的DropdownMenuItem来自API。如何禁用下拉菜单一旦用户从列表中选择一个项目?

child: DropdownButton<Partner>(
value:
_selectedLab, //USER SELECTED DROPDOWN ITEM VALUE
hint: Text("Select Lab"),
isExpanded: true,
items: data.map((Partner data) =>
DropdownMenuItem<Partner>(
child: Text("${data.partnerName}"),
value: data,
)).toList().cast<DropdownMenuItem<Partner>>(),
onChanged: (val) {
setState(() {
_selectedLab = val!;
encLabId = val.encPartnerId;
getTestByLabResult = getTestByLab();
});
},
),

Answer 1

创建一个bool on状态bool absoreTap = false;，并将DropdownButton包装为AbsorbPointer，如

AbsorbPointer(
absorbing: absoreTap,
child: DropdownButton<Partner>(
value:
_selectedLab, //USER SELECTED DROPDOWN ITEM VALUE
hint: Text("Select Lab"),
isExpanded: true,
items: data.map((Partner data) =>
DropdownMenuItem<Partner>(
child: Text("${data.partnerName}"),
value: data,
)).toList().cast<DropdownMenuItem<Partner>>(),
onChanged: (val) {
setState(() {
_selectedLab = val!;
encLabId = val.encPartnerId;
getTestByLabResult = getTestByLab();
absoreTap = true; /// 
});
},
),

你也可以检查忽略指针这里是它们之间的区别