Flutter setState函数不起作用：W / IInputConnectionWrapper4965：无效的InputConnection错误上的getTextBeforeCursor

如何解决Flutter setState函数不起作用：W / IInputConnectionWrapper4965：无效的InputConnection错误上的getTextBeforeCursor

我正在制作身体质量指数应用程序，我需要获得用户输入才能计算bmi公式。因此，我使用setState（）函数根据我从用户那里获得的信息来更新身高和体重，但它们不会被更新。你能帮忙吗？

这是我的代码：

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'calculation.dart';
void main() => runApp(MyApp());

/// This is the main application widget.
class MyApp extends StatelessWidget {
  static const String _title = 'BMI';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,home: Scaffold(
        appBar: AppBar(title: const Text(_title),centerTitle: true,backgroundColor: Colors.amber[900],),body: Center(
          child: MyStatefulWidget(),);
  }
}

enum SingingCharacter { lafayette,jefferson }

/// This is the stateful widget that the main application instantiates.
class MyStatefulWidget extends StatefulWidget {
  MyStatefulWidget({Key key}) : super(key: key);

  @override
  _MyStatefulWidgetState createState() => _MyStatefulWidgetState();
}

/// This is the private State class that goes with MyStatefulWidget.
class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  SingingCharacter _character = SingingCharacter.lafayette;
  double height=1;
  double weight=1;
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(10.0),child:Scrollbar(

      child:SingleChildScrollView(
        child:Card(
          color: Colors.amber[50],child:Column(

        children: <Widget>[
          Padding(
            padding: const EdgeInsets.fromLTRB(0,30,10,10),child: Text("Sex:",style:TextStyle(fontSize: 24,letterSpacing: 1.0)),ListTile(
            title: const Text('Female',style:TextStyle(fontSize: 18,letterSpacing: 1.0)
            ),leading: Radio(
              activeColor: Colors.orange,value: SingingCharacter.lafayette,groupValue: _character,onChanged: (SingingCharacter value) {
                setState(() {
                  _character = value;
                });
              },ListTile(
            title: const Text('Male',letterSpacing: 1.0,)
            ),value: SingingCharacter.jefferson,SizedBox(height: 10.0),Text("Your height:",letterSpacing: 1.0)
              ),SizedBox(height: 10),Padding(
                padding: const EdgeInsets.fromLTRB(30,50,child: TextField(
                  decoration: new InputDecoration(labelText: "Your height(cm)"),keyboardType: TextInputType.number,inputFormatters: <TextInputFormatter>[
                    FilteringTextInputFormatter.digitsOnly
                  ],// Only numbers can be entered
                  onSubmitted: (input1){
                    if(input1 as double>0){
                    setState(() => height=input1 as double);
                    print(input1);
               //   }
                  },SizedBox(height: 20),Text("Your weight:",letterSpacing: 1.0)
          ),Padding(
            padding: const EdgeInsets.fromLTRB(30,child:  new TextField(
                    decoration: new InputDecoration(labelText: "Your weight(kg)"),inputFormatters: <TextInputFormatter>[
                      FilteringTextInputFormatter.digitsOnly
                    ],// Only numbers can be entered
                    onSubmitted: (input2){
                      if (input2 as double>0){
           //             print(weight);
                     setState(() {
                       return weight=input2 as double;
                     });

                    }
                    },SizedBox(height: 10,RaisedButton(
      padding:EdgeInsets.fromLTRB(20,5,20,5),onPressed: (){
        return Calculation(height,weight);
    },color: Colors.amber[900],child:Text(
    'Calculate',style:TextStyle(
    color: Colors.white,fontSize: 30,letterSpacing: 2.0,SizedBox(height: 20,Text('Results: $height,$weight'),],);
    }

  }

这是计算功能：

import 'dart:math';


void Calculation(height,weight){
    double value=pow(height,2)/weight;
    print(value);
   // return value.toString();
}

void Results(value){
  if(value<18.5){
    print("kilonuz ideal kilonuzdan az.");
  }
  if(value>25){
     if(value>30){
         print("kilonuz ideal kilonuzun çok üstünde,sağlığınız risk altında.");
     }
     else{
         print("kilonuz ideal kilonuzdan fazla.");
     }
  }
  else{
      print("ideal kilonuzdasınız.");
  }
}

这是错误：

W/IInputConnectionWrapper( 4965): getSelectedText on inactive InputConnection
W/IInputConnectionWrapper( 4965): requestCursorAnchorInfo on inactive InputConnection
W/IInputConnectionWrapper( 4965): getTextBeforeCursor on inactive InputConnection
W/IInputConnectionWrapper( 4965): getTextBeforeCursor on inactive InputConnection
I/flutter ( 4965): 1.0
W/IInputConnectionWrapper( 4965): getSelectedText on inactive InputConnection
W/IInputConnectionWrapper( 4965): requestCursorAnchorInfo on inactive InputConnection
W/IInputConnectionWrapper( 4965): getTextBeforeCursor on inactive InputConnection
W/IInputConnectionWrapper( 4965): getTextBeforeCursor on inactive InputConnection