ajjx1366

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,腾讯等大公司都有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

flutter.cn/

flutterchina.club/

pub.flutter-io.cn/

www.dartcn.com/

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,可以去看这篇文章 segmentfault.com/a/11...

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: <Widget>[
        Positioned(
          top: isTop ? _globalPositionY : _globalPositionY - 200.0,
          left: isLeft ? _globalPositionX : _globalPositionX - 120.0,
          width: 120.0,
          child: Material(
            ...
          ),
        )
      ],
    );
  }
);
复制代码

} 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 pub.flutter-io.cn/packages/sh…

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);
  });
}
复制代码

} ##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~~

分类:

技术点:

相关文章: