Flutter聊天室|dart+flutter仿微信App界面|flutter聊天实例

一、项目概述

flutter-chatroom是采用基于flutter+dart+chewie+image_picker+photo_view等技术跨端开发仿微信app界面聊天室项目。实现了消息发送/动态gif表情、弹窗、图片预览、红包/朋友圈/小视频号等功能。

二、技术框架

• 编码/技术：Vscode + Flutter 1.12.13/Dart 2.7.0
• 视频组件：chewie: ^0.9.7
• 图片/拍照：image_picker: ^0.6.6+1
• 图片预览组件：photo_view: ^0.9.2
• 弹窗组件：SimpleDialog/showModalBottomSheet/AlertDialog/SnackBar（flutter封装自定义）
• 本地存储：shared_preferences: ^0.5.7+1
• 字体图标：阿里iconfont字体图标库

由于flutter基于dart语言，需要先安装Dart Sdk / Flutter Sdk，如何搭建开发环境，不作过多介绍，可以去官网查阅文档资料

https://flutter.cn/

https://flutterchina.club/

https://pub.flutter-io.cn/

https://www.dartcn.com/

如果使用vscode编辑器开发，可先安装Dart 、Flutter 、Flutter widget snippets等扩展插件

◆ flutter沉浸式状态栏/底部tabbar导航

在flutter中如何实现沉浸式透明状态栏(去掉状态栏黑色半透明背景)，去掉右上角banner提示，可以去看这篇文章

https://www.cnblogs.com/xiaoyan2017/p/12784076.html

 

◆ flutter中使用字体图标 (阿里iconfont图标)

• 方法1： 使用系统图标组件： Icon(Icons.search) 
• 方法2： 使用IconData方式： Icon(IconData(0xe60e, fontFamily: 'iconfont'), size: 24.0)

方法2 需要先下载阿里图标库字体文件，然后在pubspec.yaml中申明字体

 

通过IconData调用简单封装： GStyle.iconfont(0xe635, color: Colors.red, size: 14.0) 

class GStyle {
// __ 自定义图标
static iconfont(int codePoint, {double size = 16.0, Color color}) {
return Icon(
IconData(codePoint, fontFamily: 'iconfont', matchTextDirection: true),
size: size,
color: color,
);
}
}

 

◆ flutter中红点/圆点提示

在flutter中没有上图这个红点提示组件，如是简单封装个badge组件

 GStyle.badge(0, isdot: true) 

 GStyle.badge(13, color: Colors.green, height: 12.0, width: 12.0) 

class GStyle {
// 消息红点
static badge(int count, {Color color = Colors.red, bool isdot = false, double height = 18.0, double width = 18.0}) {
final _num = count > 99 ? '···' : count;
return Container(
alignment: Alignment.center, height: !isdot ? height : height/2, width: !isdot ? width : width/2,
decoration: BoxDecoration(color: color, borderRadius: BorderRadius.circular(100.0)),
child: !isdot ? Text('$_num', style: TextStyle(color: Colors.white, fontSize: 12.0)) : null
);
}
}

 

◆ flutter主入口页面main.dart

/**
* @tpl Flutter入口页面 | Q：282310962
*/

import 'package:flutter/material.dart';

// 引入公共样式
import 'styles/common.dart';

// 引入底部Tabbar页面导航
import 'components/tabbar.dart';

// 引入地址路由
import 'router/routes.dart';

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

class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter App',
debugShowCheckedModeBanner: false,
theme: ThemeData(
primaryColor: GStyle.appbarColor,
),
home: TabBarPage(),
onGenerateRoute: onGenerateRoute,
);
}
}

 

◆ flutter自定义弹窗实现

长按获取点坐标，通过Positioned组件left top属性实现定位，width控制弹窗宽度

InkWell(
splashColor: Colors.grey[200],
child: Container(...),
onTapDown: (TapDownDetails details) {
_globalPositionX = details.globalPosition.dx;
_globalPositionY = details.globalPosition.dy;
},
onLongPress: () {
_showPopupMenu(context);
},
),

// 长按弹窗
double _globalPositionX = 0.0; //长按位置的横坐标
double _globalPositionY = 0.0; //长按位置的纵坐标
void _showPopupMenu(BuildContext context) {
// 确定点击位置在左侧还是右侧
bool isLeft = _globalPositionX > MediaQuery.of(context).size.width/2 ? false : true;
// 确定点击位置在上半屏幕还是下半屏幕
bool isTop = _globalPositionY > MediaQuery.of(context).size.height/2 ? false : true;

showDialog(
context: context,
builder: (context) {
return Stack(
children: <Widget>[
Positioned(
top: isTop ? _globalPositionY : _globalPositionY - 200.0,
left: isLeft ? _globalPositionX : _globalPositionX - 120.0,
width: 120.0,
child: Material(
...
),
)
],
);
}
);
}

flutter中可否去掉弹窗宽高限制？通过SizedBox组件设置宽度，外层包裹布局无限制容器UnconstrainedBox组件

void _showCardPopup(BuildContext context) {
showDialog(
context: context,
builder: (context) {
return UnconstrainedBox(
constrainedAxis: Axis.vertical,
child: SizedBox(
width: 260,
child: AlertDialog(
content: Container(
...
),
elevation: 0,
contentPadding: EdgeInsets.symmetric(horizontal: 10.0, vertical: 20.0),
),
),
);
}
);
}

 

◆ flutter/dart登录、注册表单验证

TextField文本框，右侧清空文本框按钮通过Visibility组件控制

TextField(
keyboardType: TextInputType.phone,
controller: TextEditingController.fromValue(TextEditingValue(
text: formObj
ad8
['tel'],
selection: new TextSelection.fromPosition(TextPosition(affinity: TextAffinity.downstream, offset: formObj['tel'].length))
)),
decoration: InputDecoration(
hintText: "请输入手机号",
isDense: true,
hintStyle: TextStyle(fontSize: 14.0),
suffixIcon: Visibility(
visible: formObj['tel'].isNotEmpty,
child: InkWell(
child: GStyle.iconfont(0xe69f, color: Colors.grey, size: 14.0), onTap: () {
setState(() { formObj['tel'] = ''; });
}
),
),
border: OutlineInputBorder(borderSide: BorderSide.none)
),
onChanged: (val) {
setState(() { formObj['tel'] = val; });
},
)

// SnackBar提示
final _scaffoldkey = new GlobalKey<ScaffoldState>();
void _snackbar(String title, {Color color}) {
_scaffoldkey.currentState.showSnackBar(SnackBar(
backgroundColor: color ?? Colors.redAccent,
content: Text(title),
duration: Duration(seconds: 1),
));
}

本地存储使用的是 shared_preferences

https://pub.flutter-io.cn/packages/shared_preferences

void handleSubmit() async {
if(formObj['tel'] == '') {
_snackbar('手机号不能为空');
}else if(!Util.checkTel(formObj['tel'])) {
_snackbar('手机号格式有误');
}else if(formObj['pwd'] == '') {
_snackbar('密码不能为空');
}else {
// ...接口数据

// 设置存储信息
final prefs = await SharedPreferences.getInstance();
prefs.setBool('hasLogin', true);
prefs.setInt('user', int.parse(formObj['tel']));
prefs.setString('token', Util.setToken());

_snackbar('恭喜你，登录成功', color: Colors.greenAccent[400]);
Timer(Duration(seconds: 2), (){
Navigator.pushNamedAndRemoveUntil(context, '/tabbarpage', (route) => route == null);
});
}
}

flutter中获取验证码60s倒计时，使用Timer.periodic实现

// 60s倒计时
void handleVcode() {
if(formObj['tel'] == '') {
_snackbar('手机号不能为空');
}else if(!Util.checkTel(formObj['tel'])) {
_snackbar('手机号格式有误');
}else {
_countDown();
}
}
_countDown() {
if(_validTimer != null) return;

_validTimer = Timer.periodic(Duration(seconds: 1), (t) {
setState(() {
if(formObj['time'] > 0) {
formObj['disabled'] = true;
formObj['vcodeText'] = '获取验证码(${formObj["time"]--})';
}else {
formObj['time'] = 60;
formObj['vcodeText'] = '获取验证码';
formObj['disabled'] = false;

_validTimer.cancel();
_validTimer = null;
}
});
});
}

 

◆ flutter聊天页面解析

flutter中如何实现TextField换行文本框(类似微信聊天编辑框)，设置  maxLines 属性就能实现多行文本。

不过设置maxLines，文本框有一定高度，这时只需设置maxLines: null及keyboardType并在外层加个容器限制最小高度即可。

Container(
margin: GStyle.margin(10.0),
decoration: BoxDecoration(color: Colors.white, borderRadius: BorderRadius.circular(3.0)),
constraints: BoxConstraints(minHeight: 30.0, maxHeight: 150.0),
child: TextField(
maxLines: null,
keyboardType: TextInputType.multiline,
decoration: InputDecoration(
hintStyle: TextStyle(fontSize: 14.0),
isDense: true,
contentPadding: EdgeInsets.all(5.0),
border: OutlineInputBorder(borderSide: BorderSide.none)
),
controller: _textEditingController,
focusNode: _focusNode,
onChanged: (val) {

ad8
setState(() {
editorLastCursor = _textEditingController.selection.baseOffset;
});
},
onTap: () {handleEditorTaped();},
),
),

另外通过文本框focusNode属性可以实现隐藏键盘

FocusNode _focusNode = FocusNode();
...
void clickMsgPanel() {
// 隐藏键盘
_focusNode.unfocus();
setState(() { showFootToolbar = false; });
}

flutter中如何实现滚动聊天信息至底部？

通过ListView里controller的获取最大滚动距离，并通过jumpTo方法滚动。

ScrollController _msgController = new ScrollController();
...
ListView(
controller: _msgController,
padding: EdgeInsets.all(10.0),
children: renderMsgTpl(),
)

// 滚动消息至聊天底部
void scrollMsgBottom() {
timer = Timer(Duration(milliseconds: 100), () => _msgController.jumpTo(_msgController.position.maxScrollExtent));
}

ok，基于flutter+dart跨平台开发仿微信聊天实例项目就分享到这里，希望大家能喜欢！😁😁

最后附上基于electron+vue桌面端IM实例

https://www.cnblogs.com/xiaoyan2017/p/12169391.html