调试控制台在flutter中添加条件语句时出错并退出。它的异常现象我不知道为什么会发生这种情况。flutter医生很清楚，我也不知道这个错误是什么。请帮助。 错误如：
E/DartVM (31111): version=2.7.2 (Mon Mar 23 22:11:27 2020 +0100) on "android_arm64"
E/DartVM (31111): thread=31167, isolate=main(0x7fa23acc00)
E/DartVM (31111): pc 0x0000007f84450d78 fp 0x0000007f82dc81d0 /data/app/com.cdz.pmukk-2/lib/arm64/libflutter.so+0x1684d78
E/DartVM (31111): -- End of DumpStackTrace
E/DartVM (31111): [exit : sp(0) fp(0x7f82dc9198) pc(0)]
E/DartVM (31111): [stub : sp(0x7f82dc91a8) fp(0x7f82dc91e0) pc(0x7f81282a24)]
E/DartVM (31111): [dart : sp(0x7f82dc91f0) fp(0x7f82dc9270) pc(0x7f621e5ab8) package:pmukk_mobile/Screens/Sign_Up_Screen/profile_details_screen.dart__ProfileDetailsState@993294682__buildCountryStateContainer@993294682 ]
E/DartVM (31111): [dart : sp(0x7f82dc9280) fp(0x7f82dc9370) pc(0x7f621e0354) package:pmukk_mobile/Screens/Sign_Up_Screen/profile_details_screen.dart__ProfileDetailsState@993294682_build ]
E/DartVM (31111): [dart : sp(0x7f82dc9380) fp(0x7f82dc93a8) pc(0x7f6a0c8bb8) package:flutter/src/widgets/framework.dart_StatefulElement_build ]
E/DartVM (31111): [dart : sp(0x7f82dc93b8) fp(0x7f82dc9418) pc(0x7f6a565608) package:flutter/src/widgets/framework.dart_ComponentElement_performRebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc9428) fp(0x7f82dc9450) pc(0x7f6a564378) package:flutter/src/widgets/framework.dart_Element_rebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc9460) fp(0x7f82dc94a0) pc(0x7f7fa35058) package:flutter/src/widgets/framework.dart_StatefulElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dc94b0) fp(0x7f82dc94e0) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dc94f0) fp(0x7f82dc9538) pc(0x7f6940e4bc) package:flutter/src/widgets/framework.dart_SingleChildRenderObjectElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dc9548) fp(0x7f82dc9578) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dc9588) fp(0x7f82dc9610) pc(0x7f6a565a4c) package:flutter/src/widgets/framework.dart_ComponentElement_performRebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc9620) fp(0x7f82dc9648) pc(0x7f6a564378) package:flutter/src/widgets/framework.dart_Element_rebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc9658) fp(0x7f82dc9678) pc(0x7f7fa336e0) package:flutter/src/widgets/framework.dart_StatelessElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dc9688) fp(0x7f82dc96b8) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dc96c8) fp(0x7f82dc9710) pc(0x7f6940e4bc) package:flutter/src/widgets/framework.dart_SingleChildRenderObjectElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dc9720) fp(0x7f82dc9750) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dc9760) fp(0x7f82dc97a8) pc(0x7f6940e4bc) package:flutter/src/widgets/framework.dart_SingleChildRenderObjectElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dc97b8) fp(0x7f82dc97e8) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dc97f8) fp(0x7f82dc9880) pc(0x7f6a565a4c) package:flutter/src/widgets/framework.dart_ComponentElement_performRebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc9890) fp(0x7f82dc98b8) pc(0x7f6a564378) package:flutter/src/widgets/framework.dart_Element_rebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc98c8) fp(0x7f82dc9908) pc(0x7f7fa35058) package:flutter/src/widgets/framework.dart_StatefulElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dc9918) fp(0x7f82dc9948) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dc9958) fp(0x7f82dc99a0) pc(0x7f6940e4bc) package:flutter/src/widgets/framework.dart_SingleChildRenderObjectElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dc99b0) fp(0x7f82dc99e0) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dc99f0) fp(0x7f82dc9a38) pc(0x7f6940e4bc) package:flutter/src/widgets/framework.dart_SingleChildRenderObjectElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dc9a48) fp(0x7f82dc9a78) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dc9a88) fp(0x7f82dc9b10) pc(0x7f6a565a4c) package:flutter/src/widgets/framework.dart_ComponentElement_performRebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc9b20) fp(0x7f82dc9b48) pc(0x7f6a564378) package:flutter/src/widgets/framework.dart_Element_rebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc9b58) fp(0x7f82dc9b98) pc(0x7f7fa35058) package:flutter/src/widgets/framework.dart_StatefulElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dc9ba8) fp(0x7f82dc9bd8) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dc9be8) fp(0x7f82dc9c70) pc(0x7f6a565a4c) package:flutter/src/widgets/framework.dart_ComponentElement_performRebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc9c80) fp(0x7f82dc9ca8) pc(0x7f6a564378) package:flutter/src/widgets/framework.dart_Element_rebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc9cb8) fp(0x7f82dc9cd8) pc(0x7f7fa336e0) package:flutter/src/widgets/framework.dart_StatelessElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dc9ce8) fp(0x7f82dc9d18) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dc9d28) fp(0x7f82dc9db0) pc(0x7f6a565a4c) package:flutter/src/widgets/framework.dart_ComponentElement_performRebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc9dc0) fp(0x7f82dc9de8) pc(0x7f6a564378) package:flutter/src/widgets/framework.dart_Element_rebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc9df8) fp(0x7f82dc9e38) pc(0x7f7fa35058) package:flutter/src/widgets/framework.dart_StatefulElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dc9e48) fp(0x7f82dc9e78) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dc9e88) fp(0x7f82dc9ed0) pc(0x7f6940e4bc) package:flutter/src/widgets/framework.dart_SingleChildRenderObjectElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dc9ee0) fp(0x7f82dc9f10) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dc9f20) fp(0x7f82dc9fa8) pc(0x7f6a565a4c) package:flutter/src/widgets/framework.dart_ComponentElement_performRebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc9fb8) fp(0x7f82dc9fe0) pc(0x7f6a564378) package:flutter/src/widgets/framework.dart_Element_rebuild ]
E/DartVM (31111): [dart : sp(0x7f82dc9ff0) fp(0x7f82dca018) pc(0x7f6941a770) package:flutter/src/widgets/framework.dart_ProxyElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dca028) fp(0x7f82dca070) pc(0x7f6941a264) package:flutter/src/widgets/inherited_notifier.dart__InheritedNotifierElement@787313948_update ]
E/DartVM (31111): [dart : sp(0x7f82dca080) fp(0x7f82dca0b0) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dca0c0) fp(0x7f82dca108) pc(0x7f6940e4bc) package:flutter/src/widgets/framework.dart_SingleChildRenderObjectElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dca118) fp(0x7f82dca148) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dca158) fp(0x7f82dca1e0) pc(0x7f6a565a4c) package:flutter/src/widgets/framework.dart_ComponentElement_performRebuild ]
E/DartVM (31111): [dart : sp(0x7f82dca1f0) fp(0x7f82dca218) pc(0x7f6a564378) package:flutter/src/widgets/framework.dart_Element_rebuild ]
E/DartVM (31111): [dart : sp(0x7f82dca228) fp(0x7f82dca268) pc(0x7f7fa35058) package:flutter/src/widgets/framework.dart_StatefulElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dca278) fp(0x7f82dca2a8) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dca2b8) fp(0x7f82dca340) pc(0x7f6a565a4c) package:flutter/src/widgets/framework.dart_ComponentElement_performRebuild ]
E/DartVM (31111): [dart : sp(0x7f82dca350) fp(0x7f82dca378) pc(0x7f6a564378) package:flutter/src/widgets/framework.dart_Element_rebuild ]
E/DartVM (31111): [dart : sp(0x7f82dca388) fp(0x7f82dca3a8) pc(0x7f7fa336e0) package:flutter/src/widgets/framework.dart_StatelessElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dca3b8) fp(0x7f82dca3e8) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dca3f8) fp(0x7f82dca440) pc(0x7f6940e4bc) package:flutter/src/widgets/framework.dart_SingleChildRenderObjectElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dca450) fp(0x7f82dca480) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dca490) fp(0x7f82dca518) pc(0x7f6a565a4c) package:flutter/src/widgets/framework.dart_ComponentElement_performRebuild ]
E/DartVM (31111): [dart : sp(0x7f82dca528) fp(0x7f82dca550) pc(0x7f6a564378) package:flutter/src/widgets/framework.dart_Element_rebuild ]
E/DartVM (31111): [dart : sp(0x7f82dca560) fp(0x7f82dca588) pc(0x7f6941a770) package:flutter/src/widgets/framework.dart_ProxyElement_update ]
E/DartVM (31111): [dart : sp(0x7f82dca598) fp(0x7f82dca5c8) pc(0x7f6a560c08) package:flutter/src/widgets/framework.dart_Element_updateChild ]
E/DartVM (31111): [dart : sp(0x7f82dca5d8) fp(0x7f82dca660) pc(0x7f6a565a4c) package:flutter/src/widgets/framework.dart_ComponentElement_performRebuild ]
E/DartVM (31111): [dart : sp(0x7f82dca670) fp(0x7f82dca698) pc(0x7f6a564378) package:flutter/src/widgets/framework.dart_Element_rebuild ]
E/DartVM (31111): [dart : sp(0x7f82dca6a8) fp(0x7f82dca738) pc(0x7f6a557680) package:flutter/src/widgets/framework.dart_BuildOwner_buildScope ]
E/DartVM (31111): [dart : sp(0x7f82dca748) fp(0x7f82dca790) pc(0x7f69408b64) package:flutter/src/widgets/binding.dart__WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding@744399801_drawFrame ]
E/DartVM (31111): [dart : sp(0x7f82dca7a0) fp(0x7f82dca7c0) pc(0x7f69408388) package:flutter/src/widgets/binding.dart__WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding@744399801__handlePersistentFrameCallback@659452173 ]
E/DartVM (31111): [dart : sp(0x7f82dca7d0) fp(0x7f82dca808) pc(0x7f6940822c) package:flutter/src/widgets/binding.dart__WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding@744399801__handlePersistentFrameCallback@659452173__handlePersistentFrameCallback@659452173 ]
E/DartVM (31111): [dart : sp(0x7f82dca818) fp(0x7f82dca8a8) pc(0x7f69407890) package:flutter/src/widgets/binding.dart__WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding@744399801__invokeFrameCallback@694222615 ]
E/DartVM (31111): [dart : sp(0x7f82dca8b8) fp(0x7f82dca918) pc(0x7f69406a4c) package:flutter/src/widgets/binding.dart__WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding@744399801_handleDrawFrame ]
E/DartVM (31111): [dart : sp(0x7f82dca928) fp(0x7f82dca958) pc(0x7f69406504) package:flutter/src/widgets/binding.dart__WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding@744399801_scheduleWarmUpFrame_<anonymous closure> ]
E/DartVM (31111): [dart : sp(0x7f82dca968) fp(0x7f82dca9a0) pc(0x7f6a550380) dart:async_Timer__createTimer@9048458_<anonymous closure> ]
E/DartVM (31111): [dart : sp(0x7f82dca9b0) fp(0x7f82dca9d8) pc(0x7f7fbae9b8) dart:core__Closure@0150898_call ]
E/DartVM (31111): [dart : sp(0x7f82dca9e8) fp(0x7f82dcaa70) pc(0x7f6a54f274) dart:isolate__Timer@1026248__runTimers@1026248 ]
E/DartVM (31111): [dart : sp(0x7f82dcaa80) fp(0x7f82dcaaa8) pc(0x7f6a54cfe8) dart:isolate__Timer@1026248__handleMessage@1026248 ]
E/DartVM (31111): [dart : sp(0x7f82dcaab8) fp(0x7f82dcaae8) pc(0x7f6a54caac) dart:isolate__Timer@1026248__handleMessage@1026248__handleMessage@1026248 ]
E/DartVM (31111): [dart : sp(0x7f82dcaaf8) fp(0x7f82dcab20) pc(0x7f7fbae9b8) dart:core__Closure@0150898_call ]
E/DartVM (31111): [dart : sp(0x7f82dcab30) fp(0x7f82dcab58) pc(0x7f7fbb2870) dart:isolate__RawReceivePortImpl@1026248__handleMessage@1026248 ]
E/DartVM (31111): [entry : sp(0x7f82dcab68) fp(0x7f82dcac28) pc(0x7f81281a54)]
F/libc (31111): Fatal signal 6 (SIGABRT), code -6 in tid 31167 (Thread-7)
*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
Build fingerprint: 'Xiaomi/santoni/santoni:7.1.2/N2G47H/V11.0.2.0.NAMMIXM:user/release-keys'
Revision: '0'
ABI: 'arm64'
pid: 31111, tid: 31167, name: Thread-7 >>> com.cdz.pmukk <<<
signal 6 (SIGABRT), code -6 (SI_TKILL), fault addr --------
x0 0000000000000000 x1 00000000000079bf x2 0000000000000006 x3 0000000000000008
x4 0000000000000000 x5 0080000000000080 x6 0000007fa60c6000 x7 0000000000000000
x8 0000000000000083 x9 ffffffffffffffdf x10 0000000000000000 x11 0000000000000001
x12 ffffffffffffffff x13 0000000000000000 x14 0000000000000000 x15 001200335308ab97
x16 0000007fa3855ec8 x17 0000007fa3803550 x18 0000000070b204cc x19 0000007f82dcb4f8
x20 0000000000000006 x21 0000007f82dcb450 x22 0000000000000000 x23 0000007f84818000
x24 0000007f6f9d6a90 x25 0000007f6f9d6a90 x26 0000007f84813adc x27 0000000000000001
x28 0000007f84813ae8 x29 0000007f82dc8170 x30 0000007fa38009e0
sp 0000007f82dc8150 pc 0000007fa3803558 pstate 0000000060000000
backtrace:
#00 pc 000000000006b558 /system/lib64/libc.so (tgkill+8)
#01 pc 00000000000689dc /system/lib64/libc.so (pthread_kill+64)
#02 pc 0000000000023f28 /system/lib64/libc.so (raise+24)
#03 pc 000000000001c9ac /system/lib64/libc.so (abort+52)
#04 pc 0000000001580138 /data/app/com.cdz.pmukk-2/lib/arm64/libflutter.so (offset 0x1210000)
#05 pc 00000000017486cc /data/app/com.cdz.pmukk-2/lib/arm64/libflutter.so (offset 0x1210000)
#06 pc 0000000001726a54 /data/app/com.cdz.pmukk-2/lib/arm64/libflutter.so (offset 0x1210000)
#07 pc 000000000172d4ac /data/app/com.cdz.pmukk-2/lib/arm64/libflutter.so (offset 0x1210000)
#08 pc 0000000001804bf8 /data/app/com.cdz.pmukk-2/lib/arm64/libflutter.so (offset 0x1210000)
#09 pc 0000000001805760 /data/app/com.cdz.pmukk-2/lib/arm64/libflutter.so (offset 0x1210000)
#10 pc 00000000018052c8 /data/app/com.cdz.pmukk-2/lib/arm64/libflutter.so (offset 0x1210000)
#11 pc 00000000016416ac /data/app/com.cdz.pmukk-2/lib/arm64/libflutter.so (offset 0x1210000)
#12 pc 00000000016c56e4 /data/app/com.cdz.pmukk-2/lib/arm64/libflutter.so (offset 0x1210000)
#13 pc 00000000016bf45c /data/app/com.cdz.pmukk-2/lib/arm64/libflutter.so (offset 0x1210000)
#14 pc 0000000000001450 <anonymous:0000007f81280000>
Lost connection to device.
Exited (sigterm)
这是我的代码，给出了没有此条件的条件语句，它将没有任何问题。我的flutter版本是1.12.13 + hotfix.9..im两天前才升级了该版本。
Widget _buildCountryStateContainer() {
return Padding(
padding: EdgeInsets.only(top: ScreenUtil().setWidth(20.0)),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
'Country',
style: TextStyle(
color: HexColor("#585858"),
fontSize: ScreenUtil().setSp(9),
fontFamily: 'Poppins-Light'),
),
SizedBox(height: ScreenUtil().setHeight(10.0)),
Container(
color: HexColor('#F1F9FF'),
child: new DropdownButton<String>(
// icon: Icon(Icons.check),
// iconDisabledColor: Colors.blue,
underline: Container(
height: 0,
),
isExpanded: true,
items: countries.map((String datas) {
return DropdownMenuItem<String>(
value: datas,
child: Padding(
padding: EdgeInsets.all(ScreenUtil().setWidth(10.0)),
// padding: EdgeInsets.all(10),
child: Text(
datas,
style: TextStyle(
color: HexColor("#1C2344"),
fontSize: ScreenUtil().setSp(12),
fontFamily: 'Poppins-ExtraLight'),
),
),
);
}).toList(),
onChanged: (String newValue) async {
isStateLoading = false;
// setState(() {
print(newValue);
var id;
countryObj.forEach((doc) {
// finding the corresponding country id
if (doc['name'] == newValue) {
id = doc["id"];
dial_code = doc["dial_code"];
print(id);
}
});
setState(() {
dropdownValue1 = newValue;
});
fetchStates(id, newValue);
addCities();
},
value: dropdownValue1,
),
),
///problem is while adding this.......................................................................
showCountryValidator? Container(
child:Text("hi",style:TextStyle(color:Colors.red))
):Container( child:Text("invert",style:TextStyle(color:Colors.red))),
// SizedBox(height: ScreenUtil().setHeight(18.0)),
//.................................................................................................
Text(
'State',
style: TextStyle(
color: HexColor("#585858"),
fontSize: ScreenUtil().setSp(9),
fontFamily: 'Poppins-Light'),
),
SizedBox(height: ScreenUtil().setHeight(10.0)),
Container(
color: HexColor('#F1F9FF'),
child: new DropdownButton<String>(
icon:isStateLoading?Icon(Icons.arrow_drop_down)
: Container(
height: 20,
// color: Colors.red,
child: SpinKitRing(
lineWidth: 3,
color: Colors.black54,
),
),
underline: Container(
height: 0,
),
isExpanded: true,
items: states.map((String datas) {
return DropdownMenuItem<String>(
value: datas,
child: Padding(
padding: EdgeInsets.all(ScreenUtil().setWidth(10.0)),
child: Text(
datas,
style: TextStyle(
color: HexColor("#1C2344"),
fontSize: ScreenUtil().setSp(12),
fontFamily: 'Poppins-ExtraLight'),
),
),
);
}).toList(),
onChanged: (String newValue) async {
isCityLoading=false;
setState(() {
dropdownValue2 = newValue;
print(newValue);
print(stateData);
var id;
stateData.forEach((doc) {
// finding state id
if (doc['state'] == newValue) {
id = doc["state_id"];
print(id);
}
});
fetchCities(id);
});
},
value: dropdownValue2,
),
),
SizedBox(height: ScreenUtil().setHeight(18.0)),
Text(
'City',
style: TextStyle(
color: HexColor("#585858"),
fontSize: ScreenUtil().setSp(9),
fontFamily: 'Poppins-Light'),
),
SizedBox(height: ScreenUtil().setHeight(10.0)),
Container(
color: HexColor('#F1F9FF'),
child: new DropdownButton<String>(
icon:isCityLoading?Icon(Icons.arrow_drop_down)
: Container(
height: 20,
// color: Colors.red,
child: SpinKitRing(
lineWidth: 3,
color: Colors.black54,
),
),
underline: Container(
height: 0,
),
isExpanded: true,
items: city.map((String datas) {
return DropdownMenuItem<String>(
value: datas,
child: Padding(
padding: EdgeInsets.all(ScreenUtil().setWidth(10.0)),
child: Text(
datas,
style: TextStyle(
color: HexColor("#1C2344"),
fontSize: ScreenUtil().setSp(12),
fontFamily: 'Poppins-ExtraLight'),
),
),
);
}).toList(),
onChanged: (String newValue) async {
setState(() {
dropdownValue3 = newValue;
// addStates();
});
},
value: dropdownValue3,
),
),
],
),
);
}
答案 0 :(得分：0)
这是因为我做的错误之一。我只是尝试直接检查列上的布尔表达式。我只是用容器包装了它并检查了布尔表达式，现在错误消失了。 谢谢