在listView中删除textView

如何解决在listView中删除textView

当按下添加按钮时，它将添加一个TextField。当我单击减号按钮时，我希望删除TextField。但它会不断删除错误的TextField。

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',theme: ThemeData(
        primarySwatch: Colors.blue,visualDensity: VisualDensity.adaptivePlatformDensity,),home: MyHomePage(title: 'Flutter Demo Home Page'),);
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key,this.title}) : super(key: key);
  final String title;

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

class _MyHomePageState extends State<MyHomePage> {

  var commentList = List();
  TextEditingController _commentsController = TextEditingController();


  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text("Sample"),body: SingleChildScrollView(
            child: Padding(
                padding: EdgeInsets.all(10),child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,children: [
                    Row(children: [
                      Text("Comments",style: TextStyle(color: Colors.grey)),SizedBox(width: 20),Container(
                          height: 35,padding: const EdgeInsets.all(10.0),child: InkWell(
                              onTap: () {
                                setState(() {
                                  commentList.insert(
                                      0,_commentsController.text);
                                });
                              },child: Row(children: [
                                Icon(
                                  Icons.add,color: Colors.white,size: 15,SizedBox(width: 5),Text(
                                  "Add",style: TextStyle(color: Colors.white),)
                              ])),decoration: BoxDecoration(
                            borderRadius: BorderRadius.circular(10.0),color: const Color(0xff0000ff),)),]),SizedBox(height: 15),Padding(
                        padding: EdgeInsets.all(10),child: _showListViewComments()),],))));
  }

  Widget _showListViewComments() {
    return ListView.builder(
        shrinkWrap: true,physics: NeverScrollableScrollPhysics(),itemCount: commentList.length + 1,itemBuilder: (BuildContext ctxt,int index) {
          if (index < commentList.length) {
            return Padding(
                padding: EdgeInsets.only(bottom: 10),child: Row(children: [
                  Expanded(
                      child: TextField(
                          maxLines: 3,decoration: InputDecoration(
                            border: OutlineInputBorder(
                                borderRadius: const BorderRadius.all(
                                    const Radius.circular(5.0))),contentPadding: EdgeInsets.all(10),))),SizedBox(width: 10),Container(
                      width: 30,height: 30,child: FloatingActionButton(
                        backgroundColor: Colors.red,onPressed: () {
                          setState(() {
                            print(index);
                            commentList.removeAt(index);
                          });
                        },child: Icon(
                          Icons.remove,))
                ]));
          }
        });
  }
}

例如：我有文本1和文本2。我要删除文本1而不是文本2。

解决方法

每个TextField应该与定义的TextEditingController配对。我已将您的代码编辑为

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',theme: ThemeData(
        primarySwatch: Colors.blue,visualDensity: VisualDensity.adaptivePlatformDensity,),home: MyHomePage(title: 'Flutter Demo Home Page'),);
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key,this.title}) : super(key: key);
  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  List<TextEditingController> commentList = List();
  //TextEditingController _commentsController = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text("Sample"),body: SingleChildScrollView(
            child: Padding(
                padding: EdgeInsets.all(10),child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,children: [
                    Row(children: [
                      Text("Comments",style: TextStyle(color: Colors.grey)),SizedBox(width: 20),Container(
                          height: 35,padding: const EdgeInsets.all(10.0),child: InkWell(
                              onTap: () {
                                setState(() {
                                  commentList.add(TextEditingController());
                                  // commentList.insert(
                                  //     0,_commentsController.text);
                                });
                              },child: Row(children: [
                                Icon(
                                  Icons.add,color: Colors.white,size: 15,SizedBox(width: 5),Text(
                                  "Add",style: TextStyle(color: Colors.white),)
                              ])),decoration: BoxDecoration(
                            borderRadius: BorderRadius.circular(10.0),color: const Color(0xff0000ff),)),]),SizedBox(height: 15),Padding(
                        padding: EdgeInsets.all(10),child: _showListViewComments()),],))));
  }

  Widget _showListViewComments() {
    return ListView.builder(
        shrinkWrap: true,physics: NeverScrollableScrollPhysics(),itemCount: commentList.length + 1,itemBuilder: (BuildContext ctxt,int index) {
          if (index < commentList.length) {
            return Padding(
                padding: EdgeInsets.only(bottom: 10),child: Row(children: [
                  Expanded(
                      child: TextField(
                          maxLines: 3,controller: commentList[index],decoration: InputDecoration(
                            border: OutlineInputBorder(
                                borderRadius: const BorderRadius.all(
                                    const Radius.circular(5.0))),contentPadding: EdgeInsets.all(10),))),SizedBox(width: 10),Container(
                      width: 30,height: 30,child: FloatingActionButton(
                        backgroundColor: Colors.red,onPressed: () {
                          setState(() {
                            print(index);
                            commentList.removeAt(index);
                          });
                        },child: Icon(
                          Icons.remove,))
                ]));
          }
        });
  }
}