Flutter setState()在从本机端调用Flutter代码后未更新视图

Question

我正在尝试使用方法通道实现从本机调用颤振代码并按预期工作。但是在尝试设置state后呈现视图时存在问题。有人能帮忙解决这个问题吗?

实际上SimSlotInfo是从下面的小部件调用的，

List<Step> getSteps() {
return <Step>[
Step(
state: currentStep > 0 ? StepState.complete : StepState.indexed,
isActive: currentStep >= 0,
title: const Text("Send SMS"),
content: Column(
children:  [
SimSlotInfo()
],
),
),
];
}

SimSlotInfo类

import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:flutterdemo/model/device_slot.dart';

class SimSlotInfo extends StatefulWidget {
//callback function
final void Function(String) callBackFunction;
const SimSlotInfo(this.callBackFunction, {super.key});
//const SimSlotInfo({Key? key}) : super(key: key);
@override
State<SimSlotInfo> createState() => _SimSlotInfoState();
}
class _SimSlotInfoState extends State<SimSlotInfo> {
final platformMethodChannel = const MethodChannel('common_lib_plugin');
List<SimDetails> simDetailsObj = [];
//execute the below code while page loading
@override
void initState() {
super.initState();
platformMethodChannel.setMethodCallHandler(handleNativeMethodCall);
}
Future<void> handleNativeMethodCall(MethodCall call)  async {
// do some processing
switch(call.method) {
case "deviceInfo":
var simData = call.arguments;
var arrayObjsText = '[{"slot":0,"simno":"89911017061","deviceid":"3518920","carrierName":"Vodafone"},{"slot":1,"simno":"89101706","deviceid":"3511643","carrierName":"JIO"}]';
List simObjsJson = jsonDecode(arrayObjsText) as List;
simDetailsObj = simObjsJson.map((tagJson) => SimDetails.fromJson(tagJson)).toList();
setState(()  {
simDetailsObj = simDetailsObj;
});
}
}

@override
Widget build(BuildContext context) {
return Column(
children:
simDetailsObj.map((data) => RadioListTile(
dense: true,
contentPadding: EdgeInsets.zero,
title: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Text(
"${data.carrierName}",
style: const TextStyle(color: Colors.black, fontSize: 18),
),
],
),
groupValue: _selectedSim,
value: data.simno,
onChanged: (val) {

},
)).toList()
);
}
}

Answer 1

首先，您尝试将List分配给List，以便您的代码在那里得到制动。用SimDetails对象解决那个循环。这就行了

---

ParentWidget

class _ParentWidgetState extends State<ParentWidget> {
@override
Widget build(BuildContext context) {
return ChildWidget(  // <---- child widget
callSetState: (list) { // <--- callback Function 
print(list);
setState(() {
// <---  
});
},
);
}
}

---

在子部件

class ChildWidget extends StatefulWidget {
const ChildWidget({Key? key, required this.callSetState}) : super(key: key);
final Function(List<SimDetails>) callSetState; // <-- declare callback function here 
@override
State<ChildWidget> createState() => _ChildWidgetState();
}

并将setState替换为widget.callSetState

Future<void> handleNativeMethodCall(MethodCall methodCall) async {
switch (call.method) {
case 'deviceInfo':
var simData = call.arguments;
var arrayObjsText =
'[{"slot":0,"simno":"89911017061","deviceid":"3518920","carrierName":"Vodafone"},{"slot":1,"simno":"89101706","deviceid":"3511643","carrierName":"JIO"}]';
for (var data in jsonDecode(arrayObjsText)) {
simDetailsObj.add(
SimDetails(
slot: data['slot'],
simno: data['simno'],
deviceid: data['deviceid'],
carrierName: data['carrierName'],
),
);
}
/// setState(() {});
widget.callSetState(simDetailsObj);

break;
default:
}}