Question

我正在使用ListView.builder创建音频列表，选择播放项时我需要将其单独更改为播放项，我尝试过bool，但播放或暂停时会更改列表中的所有项，有人可以帮忙吗？

Answer 1

import 'package:flutter/material.dart';

class Sample extends StatefulWidget {
  @override
  _SampleState createState() => _SampleState();
}

class _SampleState extends State<Sample> {
  bool isPressed = false;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: ListView(
        children: [
          Column(
            children: [
              IconButton(
                  icon: Icon(isPressed
                      ? Icons.play_circle_filled
                      : Icons.pause_circle_filled),
                  onPressed: () {
                    setState(() {
                      isPressed = !isPressed;
                    });
                  }),
              IconButton(
                  icon: Icon(isPressed
                      ? Icons.play_circle_filled
                      : Icons.pause_circle_filled),
                  onPressed: () {
                    setState(() {
                      isPressed = !isPressed;
                    });
                  }),
              PlayPause(
                isPressed: isPressed,
              ),
              PlayPause(),
            ],
          )
        ],
      ),
    );
  }
}

class PlayPause extends StatefulWidget {
  const PlayPause({
    Key key,
    this.isPressed = false,
  }) : super(key: key);
  final bool isPressed;

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

class _PlayPauseState extends State<PlayPause> {
  bool _isPressed;
  @override
  void initState() {
    super.initState();
    _isPressed = widget.isPressed;
  }

  @override
  Widget build(BuildContext context) {
    return IconButton(
        icon: Icon(
            _isPressed ? Icons.play_circle_filled : Icons.pause_circle_filled),
        onPressed: () {
          setState(() {
            _isPressed = !_isPressed;
          });
        });
  }
}

Answer 2

您可能具有布尔值列表来保存选择了哪个按钮，然后将布尔值作为参数传递给音频小部件，并使用布尔值来更改图标。

还传递回调函数来更改布尔列表，因为您必须从父窗口小部件中更改列表，因此需要回调函数。

 List<bool> audioSelectedList = List.generate(AudioList.length, (i) => false);

// This is a callback function that Audio will call when the button is clicked.
  selected(int index){
// set only one bool to be true
    setState(() {
      audioSelectedList=List.generate(AudioList.length, (i) => false);// set all to false
      audioSelectedList[index]=true;  // set the selected index to be true
    });
  }

ListView：

ListView.builder(
          itemCount: AudioList.length,
          itemBuilder: (context, index) => Audio(
            selected: selected, // pass the callback function
            index: index, // use to call selected(index)
            isSelected: audioSelectedList[index], // only one bool is true in the list which is the selected index.
          ),
        ),

Answer 3

不要为所有音频使用一个布尔值，您可以使用集合为音频列表中的所有内容定义布尔值，然后单击以更改音频的布尔值。

ListView.Builder播放/暂停按钮颤动

3 个答案: