1、项目介绍
Flutter是目前比较流行的跨平台开发技术,凭借其出色的性能获得很多前端技术爱好者的关注,比如阿里闲鱼,美团,腾讯等大公司都在投入相关案例生产使用。flutter_chatroom项目是基于Flutter+Dart+chewie+photo_view+image_picker等技术开发的跨平台仿微信app聊天界面应用,实现了消息/表情发送、图片预览、长按菜单、红包/小视频/朋友圈等功能。
2、技术框架
使用技术: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:showModalBottomSheet/AlertDialog/SnackBar本地存储:shared_preferences: ^0.5.7+1字体图标:阿里iconfont字体图标库鉴于flutter基于dart语言,需要安装Dart Sdk / Flutter Sdk,至于如何搭建开发环境,可以去官网查阅文档资料
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https://flutterchina.club/
https://pub.flutter-/
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使用vscode编辑器,可先安装Dart 、Flutter 、Flutter widget snippets等扩展插件
3、flutter沉浸式状态栏/底部tabbar
flutter中如何实现顶部全背景沉浸式透明状态栏(去掉状态栏黑色半透明背景),去掉右上角banner
4、flutter图标组件/IconData自定义封装组件
1、使用系统图标组件: Icon(Icons.search) 2、使用IconData方式: Icon(IconData(0xe60e, fontFamily:'iconfont'), size:24.0)使用第二种方式需要先下载阿里图标库字体文件,然后在pubspec.yaml中引入字体
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, ); }}
调用非常简单,可自定义颜色、字体大小;GStyle.iconfont(0xe635, color: Colors.orange, size: 17.0)
5、flutter实现badge红点/圆点提示
如上图:在flutter中没有圆点提示组件,需要自己封装实现;
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 ); }}
支持自定义红点大小、颜色,默认数字超过99就...显示;GStyle.badge(0, isdot:true)GStyle.badge(13)GStyle.badge(29, color: Colors.orange, height: 15.0, width: 15.0)
6、flutter长按自定义弹窗
在flutter中如何实现长按,并在长按位置弹出菜单,类似微信消息长按弹窗效果;通过InkWell组件提供的onTapDown事件获取坐标点实现
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: [ Positioned( top: isTop ? _globalPositionY : _globalPositionY - 200.0, left: isLeft ? _globalPositionX : _globalPositionX - 120.0, width: 120.0, child: Material(... ), )], );} );}
flutter如何实现去掉AlertDialog弹窗大小限制?
可通过SizedBox和无限制容器UnconstrainedBox组件实现
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), ),), );} );}
7、flutter登录/注册表单|本地存储
flutter提供了两个文本框组件:TextField 和 TextFormField本文是使用TextField实现,并在文本框后添加清空文本框/密码查看图标
TextField( keyboardType: TextInputType.phone, controller: TextEditingController.fromValue(TextEditingValue( text: formObj['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; }); },)TextField( decoration: InputDecoration( hintText: "请输入密码", isDense: true, hintStyle: TextStyle(fontSize: 14.0), suffixIcon: InkWell(child: Icon(formObj['isObscureText'] ? Icons.visibility_off : Icons.visibility, color: Colors.grey, size: 14.0),onTap: () { setState(() {formObj['isObscureText'] = !formObj['isObscureText']; });}, ), border: OutlineInputBorder(borderSide: BorderSide.none) ), obscureText: formObj['isObscureText'], onChanged: (val) { setState(() { formObj['pwd'] = val; }); },)
验证消息提示则是使用flutter提供的SnackBar实现
// SnackBar提示final _scaffoldkey = new GlobalKey();void _snackbar(String title, {Color color}) { _scaffoldkey.currentState.showSnackBar(SnackBar(backgroundColor: color ?? Colors.redAccent,content: Text(title),duration: Duration(seconds: 1), ));}
另外本地存储使用的是shared_preferences,至于如何使用可参看https://pub.flutter-/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);}); }}
8、flutter聊天页面功能
在flutter中如何实现类似上图编辑器功能?通过TextField提供的多行文本框属性maxLines就可实现。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) {setState(() { editorLastCursor = _textEditingController.selection.baseOffset;}); }, onTap: () {handleEditorTaped();}, ),),
flutter实现滚动聊天信息到最底部
通过ListView里controller属性提供的jumpTo方法及_msgController.position.maxScrollExtent
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));}
行了,基于flutter/dart开发聊天室实例就介绍到这里,希望能喜欢~~
最后
Flutter作为跨平台开发技术、Flutter以其美观、快速、高效、开放等优势迅速俘获人心,但很多Flutter兴趣爱好者进阶学习缺少资源,今天我把搜集和整理的这份学习资源分享给有需要的人,若是有所需要,麻烦各位转发一下(可以帮助更多的人看到哟!),记得一定要关注+转发,然后私信@芜湖Android“Flutter”,即可回复免费下载的方式!!
以下是部分内容展示:
也希望 Flutter 生态越来越好 (flutter开发App效率真的很高,开发体验也是很好的 )。