Flutter伪微信-008-PopupMenuButton组件实现下拉菜单

前言

我们来完成上一节剩下的任务右边菜单按钮 

• 1.导航栏右边菜单按钮（扫一扫等）未完成✅
• 2.导航栏下方的搜索框 完成✅
• 3.聊天列表 完成✅
• 4.消息表左滑 未完成✅
• 5.消息未读数量小红点 完成✅

预览

实现

自己找寻了一圈好像没有Flutter原生的组件支持这个功能。

所以找到了第三方的组件flutter_slidable

构造

您可以通过Slidable两种不同的方式创建一个：

• 通过调用Slidable构造函数并传递滑动动作列表。
• Slidable.builder如果要在动画过程中获得特殊效果，则可以调用构造函数并传递滑动动作生成器。

Slidable需要满足以下条件：

• 滑动动作（有关详细信息，请参见下文）。它们可以是任何小部件。为了方便起见，此程序包具有2个内置的侧面动作小部件。
• slide的actions小部件。这就是控制幻灯片菜单的布局和动画的因素。
• 滑动作用范围和列表项之间的范围比率。
• 一个child组件。

通过direction参数可以选择是否要在水平（默认）或垂直滑动时显示动作。

ListView(
    children: <Widget>[
        Slidable(
            actionPane: SlidableScrollActionPane(),//滑出选项的面板 动画
            actionExtentRatio: 0.25,
            child: ListItem(title:title),
            actions: <Widget>[//左侧按钮列表
                IconSlideAction(
                    caption: 'Archive',
                    color: Colors.blue,
                    icon: Icons.archive,
                    onTap: () => _showSnackBar('Archive'),
                ),
                IconSlideAction(
                    caption: 'Share',
                    color: Colors.indigo,
                    icon: Icons.share,
                    onTap: () => _showSnackBar('Share'),
                ),
            ],
            secondaryActions: <Widget>[//右侧按钮列表
                IconSlideAction(
                    caption: 'More',
                    color: Colors.black45,
                    icon: Icons.more_horiz,
                    onTap: () => _showSnackBar('More'),
                ),
                IconSlideAction(
                    caption: 'Delete',
                    color: Colors.red,
                    icon: Icons.delete,
                    closeOnTap: false,
                    onTap: (){
                        _showSnackBar('Delete');
                    },
                ),
            ],
        )
    ]
）

按钮项使用两种widget来构建： - SlideAction，这是最灵活的。您可以选择背景色或任何装饰，并且它将任何小部件作为child。 - IconSlideAction，需要一个图标。它可以在图标下方具有背景色和标题。

滑动动画效果

内置四种滑动的动画：(不仔细看很难看出区别来)

SlidableBehindActionPane()

SlidableDrawerActionPane()

SlidableScrollActionPane()

SlidableScrollActionPane()

滑动删除

设置dismissal属性即可启用滑动删除动画：

dismissal: SlidableDismissal(
    child: SlidableDrawerDismissal(),
    onWillDismiss: (actionType){
        return showDialog<bool>(
            context: context,
            builder: (context) {
                return AlertDialog(
                    title: Text('提示？'),
                    content: Text('确定删除该条记录？'),
                    actions: <Widget>[
                        FlatButton(
                        child: Text('取消'),
                        onPressed: () => Navigator.of(context).pop(false),
                        ),
                        FlatButton(
                        child: Text('确定'),
                        onPressed: () => Navigator.of(context).pop(true),
                        ),
                    ],
                );
            }
        );
    },
    onDismissed: (actionType) {
        print(actionType);

    },
),

完整代码

import 'package:date_format/date_format.dart';
import 'package:flutter/material.dart';
import 'package:flutter_slidable/flutter_slidable.dart';
import 'package:pseudo_we_chat/ui/badge_avatar.dart';

import '../../constant/style.dart';

class MessagePage extends StatefulWidget {
  const MessagePage({Key? key}) : super(key: key);

  @override
  State<MessagePage> createState() => _MessagePageState();
}

class _MessagePageState extends State<MessagePage> {
  //定义列表数据
  final List<MessageData> _messageList = [
    MessageData(
        id: BigInt.from(1),
        avatar:
            "https://d36tnp772eyphs.cloudfront.net/blogs/1/2018/02/Taj-Mahal.jpg",
        name: "张三123",
        message:
            "ZFLEX对UIKit的一层封装，主要包含一个数据驱动的列表框架、和UIKit中常用控件的链式拓展，ZZFLEX相关资料正在整理中，目前已经开源，ZFLEX对UIKit的一层封装，主要包含一个数据驱动的列表框架、和UIKit中常用控件的链式拓展，ZZFLEX相关资料正在整理中，目前已经开源",
        lastTime: DateTime.now(),
        unReadNum: 13),
    MessageData(
        id: BigInt.from(2),
        avatar: "https://www.itying.com/images/flutter/3.png",
        name: "云淡风轻",
        message: "[图片]",
        lastTime: DateTime.now().subtract(const Duration(minutes: 30)),
        unReadNum: 0),
    MessageData(
        id: BigInt.from(1),
        avatar: "https://www.itying.com/images/flutter/2.png",
        name: "魅力人生",
        message: "今天是个好日子。",
        lastTime: DateTime.now().subtract(const Duration(hours: 1)),
        unReadNum: 9),
    MessageData(
        id: BigInt.from(1),
        avatar: "https://www.itying.com/images/flutter/1.png",
        name: "随访飘逸",
        message: "你好啊",
        lastTime: DateTime.now().subtract(const Duration(hours: 2)),
        unReadNum: 66),
    MessageData(
        id: BigInt.from(1),
        avatar:
            "https://d36tnp772eyphs.cloudfront.net/blogs/1/2018/02/Taj-Mahal.jpg",
        name: "张三",
        message: "Hello word!",
        lastTime: DateTime.now(),
        unReadNum: 120),
    MessageData(
        id: BigInt.from(1),
        avatar: "https://www.itying.com/images/flutter/3.png",
        name: "云淡风轻",
        message: "[图片]",
        lastTime: DateTime.now().subtract(const Duration(minutes: 30)),
        unReadNum: 1),
    MessageData(
        id: BigInt.from(1),
        avatar: "https://www.itying.com/images/flutter/2.png",
        name: "魅力人生",
        message: "今天是个好日子。",
        lastTime: DateTime.now().subtract(const Duration(hours: 1)),
        unReadNum: 1),
    MessageData(
        id: BigInt.from(1),
        avatar: "https://www.itying.com/images/flutter/1.png",
        name: "随访飘逸",
        message: "你好啊",
        lastTime: DateTime.now().subtract(const Duration(hours: 2)),
        unReadNum: 1),
    MessageData(
        id: BigInt.from(1),
        avatar:
            "https://d36tnp772eyphs.cloudfront.net/blogs/1/2018/02/Taj-Mahal.jpg",
        name: "张三",
        message: "Hello word!",
        lastTime: DateTime.now(),
        unReadNum: 1),
    MessageData(
        id: BigInt.from(1),
        avatar: "https://www.itying.com/images/flutter/3.png",
        name: "云淡风轻",
        message: "[图片]",
        lastTime: DateTime.now().subtract(const Duration(minutes: 30)),
        unReadNum: 1),
    MessageData(
        id: BigInt.from(1),
        avatar: "https://www.itying.com/images/flutter/2.png",
        name: "魅力人生",
        message: "今天是个好日子。",
        lastTime: DateTime.now().subtract(const Duration(hours: 1)),
        unReadNum: 10),
    MessageData(
        id: BigInt.from(1),
        avatar: "https://www.itying.com/images/flutter/1.png",
        name: "随访飘逸",
        message: "你好啊",
        lastTime: DateTime.now().subtract(const Duration(hours: 2)),
        unReadNum: 1),
    MessageData(
        id: BigInt.from(1),
        avatar:
            "https://d36tnp772eyphs.cloudfront.net/blogs/1/2018/02/Taj-Mahal.jpg",
        name: "张三",
        message: "Hello word!",
        lastTime: DateTime.now(),
        unReadNum: 1),
    MessageData(
        id: BigInt.from(1),
        avatar: "https://www.itying.com/images/flutter/3.png",
        name: "云淡风轻",
        message: "[图片]",
        lastTime: DateTime.now().subtract(const Duration(minutes: 30)),
        unReadNum: 1),
    MessageData(
        id: BigInt.from(1),
        avatar: "https://www.itying.com/images/flutter/2.png",
        name: "魅力人生",
        message: "今天是个好日子。",
        lastTime: DateTime.now().subtract(const Duration(hours: 1)),
        unReadNum: 1),
    MessageData(
        id: BigInt.from(1),
        avatar: "https://www.itying.com/images/flutter/1.png",
        name: "随访飘逸",
        message: "你好啊",
        lastTime: DateTime.now().subtract(const Duration(hours: 2)),
        unReadNum: 1)
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          elevation: 0,
          title: const Text(
            "微信",
            style: TextStyle(color: Style.appBarTextColor),
          ),
          backgroundColor: Style.appBarBackgroundColor,
        ),
        body: Container(
            color: Style.contentBackgroundColor,
            child: Column(
              children: [
                //聊天列表
                Expanded(
                  flex: 1,
                  child: SlidableAutoCloseBehavior(
                    child: ListView.builder(
                        itemCount: _messageList.length,
                        itemBuilder: (BuildContext context, int index) {
                          var item = _messageList[index];
                          return Column(
                            children: [
                              //搜索按钮
                              index == 0
                                  ? Container(
                                      width: double.infinity,
                                      padding: const EdgeInsets.only(
                                          left: 10,
                                          right: 10,
                                          top: 5,
                                          bottom: 5),
                                      decoration: const BoxDecoration(
                                          color: Style
                                              .messageSearchBackgroundColor),
                                      child: ElevatedButton(
                                        style: ButtonStyle(
                                            elevation:
                                                MaterialStateProperty.all(0),
                                            backgroundColor:
                                                MaterialStateProperty.all(
                                                    Colors.white)),
                                        child: Row(
                                          mainAxisAlignment:
                                              MainAxisAlignment.center,
                                          children: const [
                                            Icon(
                                              Icons.search,
                                              color: Colors.grey,
                                            ),
                                            Text(
                                              "搜索",
                                              style: TextStyle(
                                                  fontSize: 20,
                                                  color: Colors.grey),
                                            )
                                          ],
                                        ),
                                        onPressed: () {},
                                      ),
                                    )
                                  : const SizedBox(),
                              Column(
                                children: [
                                  Slidable(
                                    // Specify a key if the Slidable is dismissible.
                                    key: ValueKey("$index"),
                                    groupTag: "ccc",
                                    // 把所有item归类到一个组, 保证同时只出现一个滑动的效果
                                    // The end action pane is the one at the right or the bottom side.
                                    endActionPane: ActionPane(
                                      extentRatio: 0.7,
                                      dragDismissible: false,
                                      motion: ScrollMotion(),
                                      children: [
                                        item.unReadNum == 0
                                            ? SlidableAction(
                                                // An action can be bigger than the others.
                                                flex: 2,
                                                onPressed:
                                                    (BuildContext context) {},
                                                backgroundColor: Colors.blue,
                                                foregroundColor: Colors.white,
                                                label: '标记未读',
                                              )
                                            : SlidableAction(
                                                // An action can be bigger than the others.
                                                flex: 2,
                                                onPressed:
                                                    (BuildContext context) {},
                                                backgroundColor: Colors.blue,
                                                foregroundColor: Colors.white,
                                                label: '标记已读',
                                              ),
                                        SlidableAction(
                                          flex: 1,
                                          onPressed: (BuildContext context) {},
                                          backgroundColor: Colors.amber,
                                          foregroundColor: Colors.white,
                                          label: '不显示',
                                        ),
                                        SlidableAction(
                                          autoClose: false,
                                          flex: 1,
                                          onPressed: (BuildContext context) {},
                                          backgroundColor: Colors.deepOrange,
                                          foregroundColor: Colors.white,
                                          label: '删除',
                                        ),
                                      ],
                                    ),

                                    // The child of the Slidable is what the user sees when the
                                    // component is not dragged.
                                    child: ListTile(
                                      //头像
                                      leading: BadgeAvatar(
                                        avatar: item.avatar,
                                        num: item.unReadNum,
                                      ),
                                      //名称和时间
                                      title: Row(
                                        children: [
                                          //名称
                                          Expanded(
                                              flex: 17,
                                              child: Text(item.name,
                                                  style: const TextStyle(
                                                      fontSize: 18,
                                                      fontWeight:
                                                          FontWeight.w500))),
                                          //右侧时间
                                          Expanded(
                                              flex: 3,
                                              child: Text(
                                                formatDate(item.lastTime,
                                                    [HH, ':', nn]),
                                                style: const TextStyle(
                                                    fontSize: 12,
                                                    color: Colors.grey),
                                              )),
                                        ],
                                      ),
                                      //消息内容
                                      subtitle: Padding(
                                        padding: const EdgeInsets.only(top: 10),
                                        child: Text(item.message,
                                            overflow: TextOverflow.ellipsis,
                                            maxLines: 1,
                                            style: const TextStyle(
                                                fontSize: 16,
                                                color: Colors.grey)),
                                      ),
                                    ),
                                  ),

                                  //下划线
                                  Padding(
                                    padding: index == _messageList.length - 1
                                        ? const EdgeInsets.only(left: 0)
                                        : const EdgeInsets.only(left: 80),
                                    child: const Divider(),
                                  )
                                ],
                              )
                            ],
                          );
                        }),
                  ),
                ),
              ],
            )));
  }
}

class MessageData {
  const MessageData(
      {required this.id,
      required this.avatar,
      required this.name,
      required this.message,
      required this.unReadNum,
      required this.lastTime});

  /// id
  final BigInt id;

  /// 头像
  final String avatar;

  /// 名称
  final String name;

  /// 消息
  final String message;

  /// 消息未读数量
  final int unReadNum;

  /// 消息时间
  final DateTime lastTime;
}

项目链接

github.com/BadKid90s/p…