如何在按下按钮时添加自定义小部件

Question

我使用其他几个线程创建了一个应用程序，您在其中输入文本字段中的某些文本，然后当您按下按钮时，会将默认容器添加到列表中，并且其中一个字段中的文本。但是，当我键入文本并添加小部件时，所有条目的文本都会更改，而不仅仅是添加的文本。这是我的代码：

    import 'dart:core';
    import 'package:flutter/material.dart';

    void main() => runApp(MyApp());

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

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int count = 0;
  TextEditingController noteSend = TextEditingController();

  @override
  Widget build(BuildContext context) {
    List<Widget> children = new List.generate(
        count,
        (int i) => new InputWidget(
              i,
              noteRec: noteSend.text,
            ));

    return new Scaffold(
        appBar: new AppBar(title: new Text('some title')),
        body: Column(
          children: <Widget>[
            Container(
              child: TextField(
                controller: noteSend,
              ),
              color: Colors.lightBlueAccent,
              width: 150,
              height: 50,
            ),
            Expanded(
              child: ListView(
                children: children,
                scrollDirection: Axis.vertical,
              ),
            ),
          ],
        ),
        floatingActionButton: new FloatingActionButton(
          child: new Icon(Icons.add),
          onPressed: () {
            setState(() {
              count = count + 1;
            });
          },
        ));
  }
}

class InputWidget extends StatefulWidget {
  final int index;
  final String noteRec;
  InputWidget(this.index, {Key key, this.noteRec}) : super(key: key);

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

class _InputWidgetState extends State<InputWidget> {
  @override
  Widget build(BuildContext context) {
    return new Container(
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(10),
      ),
      child: Row(
        children: <Widget>[
          Column(
            children: <Widget>[
              Icon(
                Icons.image,
                size: 75,
              )
            ],
          ),
          Container(
            margin: EdgeInsets.only(left: 80, right: 30),
            child: Column(
              children: <Widget>[
                Text('Note'),
              ],
            ),
          ),
          Column(
            children: <Widget>[
              Text("${widget.noteRec}"),
            ],
          ),
        ],
      ),
    );
  }
}

如何使每个条目的文本都不同？

Answer 1

尝试此代码

Container(
            height: 200,
            child: Column(
              children: <Widget>[
                Expanded(
                  child: buildGridView(),
                )
              ],
            ),
          ),

然后调用将返回小部件的buildGridView

Widget buildGridView() {
        return Text('text here'); // your future widget
  }

Answer 2

List<Widget> children = new List.generate(
    count,
    (int i) => new InputWidget(
          i,
          noteRec: noteSend.text,
        ));

在此代码中，为子级中所有元素设置输入文本。这就是所有条目都更改为相同文本的原因。当您按下保存按钮并在List.generate中调用它时，可以将文本保存到字符串列表中。

List<Widget> children = new List.generate(
    count,
    (int i) => new InputWidget(
          i,
          noteRec: listString[i],
        ));