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青岛模板网站建设价格,广西百度seo,用最少的钱做网站,凡科可以做视频网站吗监听屏幕触摸事件(Listener)PointerEvent(忽略事件)GestureDetector 手势点击拖拽控件缩放识别事件竞争机制NotificationListener 监听滑动 1.监听屏幕触摸事件(Listener) onPointerDown 点击onPointerMove 移动onPointerUp 离开onPointerCancel 取消 Listener(child: Contain…
  • 监听屏幕触摸事件(Listener)
  • PointerEvent(忽略事件)
  • GestureDetector 手势点击
  • 拖拽控件
  • 缩放识别
  • 事件竞争机制
  • NotificationListener 监听滑动

1.监听屏幕触摸事件(Listener)

  • onPointerDown 点击
  • onPointerMove 移动
  • onPointerUp 离开
  • onPointerCancel 取消
Listener(child: Container(alignment: Alignment.center,color: Colors.blue,width: 240.0,height: 120.0,child: Text(_opName,style: TextStyle(color: Colors.white),),),onPointerDown: (PointerDownEvent event) =>_showEventText('onPointerDown'),onPointerMove: (PointerMoveEvent event) =>_showEventText('onPointerMove'),onPointerUp: (PointerUpEvent event) => _showEventText('onPointerUp'),onPointerCancel: (PointerCancelEvent event) =>_showEventText('onPointerCancel'),
)

2.PointerEvent(忽略事件)

  • IgnorePointer : ignoring是否忽略点击,默认true 不可以点击
  • AbsorbPointer : absorbing child 是否接受点击事件,默认true 可以点击
import 'package:flutter/material.dart';class PointerEventIgnorePage extends StatefulWidget {@override_PointerEventIgnorePageState createState() =>new _PointerEventIgnorePageState();
}class _PointerEventIgnorePageState extends State<PointerEventIgnorePage> {bool _ignore = true;@overrideWidget build(BuildContext context) {return Scaffold(appBar: AppBar(title: Text('忽略事件')),body: Container(alignment: AlignmentDirectional.center,child: Column(children: <Widget>[Switch(value: _ignore,onChanged: (value) {setState(() => _ignore = value);},),GestureDetector(onTap: () => print('GestureDetector Clicked!'),child: IgnorePointer(ignoring: _ignore,child: RaisedButton(onPressed: () => print('IgnorePointer Clicked!'),child: Text('IgnorePointer'),),),),GestureDetector(onTap: () => print('GestureDetector Clicked!'),child: AbsorbPointer(absorbing: _ignore,child: RaisedButton(onPressed: () => print('AbsorbPointer Clicked!'),child: Text('AbsorbPointer'),),),),],),),);}
}

3.GestureDetector 手势点击

  • onTap 点击
  • onTapUp
  • onTapDown
  • onTapCancel
  • onDoubleTap 双击
  • onLongPress 长按
  • onVerticalDragDown 拖拽
  • onVerticalDragStart
  • onVerticalDragUpdate
  • onVerticalDragEnd
  • onVerticalDragCancel
  • onHorizontalDragDown
  • onHorizontalDragStart
  • onHorizontalDragUpdate
  • onHorizontalDragEnd
  • onHorizontalDragCancel
class GestureDetectorPage extends StatefulWidget {@override_GestureDetectorState createState() => new _GestureDetectorState();
}class _GestureDetectorState extends State<GestureDetectorPage> {String _opName = "未检测到操作";@overrideWidget build(BuildContext context) {return Scaffold(appBar: AppBar(title: Text("GestureDetector手势识别"),),body: Center(child: GestureDetector(child: Container(alignment: Alignment.center,color: Colors.blue,width: 240.0,height: 120.0,child: Text(_opName,style: TextStyle(color: Colors.white),),),onTap: () => _showEventText("Tap"),onTapUp: (e) => _showEventText("TapUp"),onTapDown: (e) => _showEventText("TapDown"),onTapCancel: () => _showEventText("TapCancel"),onDoubleTap: () => _showEventText("DoubleTap"),onLongPress: () => _showEventText("LongPress"),onVerticalDragDown: (e) => _showEventText("onVerticalDragDown"),onVerticalDragStart: (e) => _showEventText("onVerticalDragStart"),onVerticalDragUpdate: (e) => _showEventText("onVerticalDragUpdate"),onVerticalDragEnd: (e) => _showEventText("onVerticalDragEnd"),onVerticalDragCancel: () => _showEventText("onVerticalDragCancel"),onHorizontalDragDown: (e) => _showEventText("onHorizontalDragDown"),onHorizontalDragStart: (e) => _showEventText("onHorizontalDragStart"),onHorizontalDragUpdate: (e) => _showEventText("onHorizontalDragUpdate"),onHorizontalDragEnd: (e) => _showEventText("onHorizontalDragEnd"),onHorizontalDragCancel: () => _showEventText("onHorizontalDragCancel"),
//          onPanDown: (e) => _showEventText("onPanDown"),
//          onPanStart: (e) => _showEventText("onPanStart"),
//          onPanUpdate: (e) => _showEventText("onPanUpdate"),
//          onPanEnd: (e) => _showEventText("onPanEnd"),
//          onScaleStart: (e) => _showEventText("onScaleStart"),
//          onScaleUpdate: (e) => _showEventText("onScaleUpdate"),
//          onScaleEnd: (e) => _showEventText("onScaleEnd"),),),);}void _showEventText(String text) {setState(() {_opName = text;});print(_opName);}
}

4.拖拽控件

效果图

拖拽

关键代码

import 'package:flutter/material.dart';class DragPage extends StatefulWidget {@override_DragState createState() => new _DragState();
}class _DragState extends State<DragPage> with SingleTickerProviderStateMixin {double _top = 0.0;double _left = 0.0;double _size = 100.0;@overrideWidget build(BuildContext context) {return Scaffold(appBar: AppBar(title: Text("拖拽控件"),),body: Stack(children: <Widget>[Positioned(top: _top,left: _left,child: GestureDetector(child: FlutterLogo(size: _size,),onPanUpdate: (e) {setState(() {_left += e.delta.dx;_top += e.delta.dy;});},),)],),);}
}

5.缩放识别

import 'package:flutter/material.dart';class ScalePage extends StatefulWidget {@override_ScaleState createState() => new _ScaleState();
}class _ScaleState extends State<ScalePage> {double _size = 100.0;@overrideWidget build(BuildContext context) {return Scaffold(appBar: AppBar(title: Text("缩放识别"),),body: Center(child: GestureDetector(child: Container(alignment: Alignment.center,child: FlutterLogo(size: _size,),),onScaleUpdate: (ScaleUpdateDetails e) {setState(() {_size = 300 * e.scale.clamp(.5, 10.0);});},),),);}
}

6.GestureRecognizer(对于不带点击事件的Widget，例如RichText)

关键代码

recognizer: _tapGestureRecognizer..onTap = () {showInSnackBar("built: 建造");},

import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';class GestureRecognizerPage extends StatefulWidget {@override_GestureRecognizerState createState() => new _GestureRecognizerState();
}class _GestureRecognizerState extends State<GestureRecognizerPage> {TapGestureRecognizer _tapGestureRecognizer = new TapGestureRecognizer();final GlobalKey<ScaffoldState> _scaffoldKey = new GlobalKey<ScaffoldState>();@overridevoid dispose() {_tapGestureRecognizer.dispose();super.dispose();}@overrideWidget build(BuildContext context) {return Scaffold(key: _scaffoldKey,appBar: AppBar(title: Text("GestureRecognizer"),),body: Padding(padding: EdgeInsets.all(10.0),child: Column(children: <Widget>[Text.rich(TextSpan(children: [TextSpan(text: "Room is not ",style: TextStyle(fontSize: 25.0),),TextSpan(text: "built",style: TextStyle(fontSize: 25.0,color: Colors.blue,fontWeight: FontWeight.bold,decoration: TextDecoration.underline,decorationThickness: 3.0,decorationColor: Colors.amber,decorationStyle: TextDecorationStyle.solid,),recognizer: _tapGestureRecognizer..onTap = () {showInSnackBar("built: 建造");},),TextSpan(text: " in one day.",style: TextStyle(fontSize: 25.0),),],),),],),),);}void showInSnackBar(String value) {_scaffoldKey.currentState.showSnackBar(new SnackBar(content: new Text(value,style: TextStyle(fontSize: 25.0),),),);}
}

7.事件竞争机制

import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';class BothDirectionPage extends StatefulWidget {@override_BothDirectionState createState() => new _BothDirectionState();
}
class _BothDirectionState extends State<BothDirectionPage> {double _top = 0.0;double _left = 0.0;@overrideWidget build(BuildContext context) {return Scaffold(appBar: AppBar(title: Text("事件竞争机制"),),body: Stack(children: <Widget>[Positioned(top: _top,left: _left,child: GestureDetector(child: FlutterLogo(size: 100,),onVerticalDragUpdate: (DragUpdateDetails e) {setState(() {_top += e.delta.dy;});print("垂直胜出");},onHorizontalDragUpdate: (DragUpdateDetails e) {setState(() {_left += e.delta.dx;});print("水平胜出");},onTapDown: (e) {print("按下");},onTapUp: (e) {print("松开");},onHorizontalDragEnd: (e) {print("水平移动结束");},onVerticalDragEnd: (e) {print("垂直移动结束");},),)],),);}
}

8.NotificationListener

监听滚动通知<ScrollNotification>

  • Scroll Start
  • Scroll Update
  • Scroll End

效果图

通知中心

关键代码

import 'package:flutter/material.dart';class ScrollStatusPage extends StatefulWidget {@override_ScrollStatusState createState() => new _ScrollStatusState();
}class _ScrollStatusState extends State<ScrollStatusPage> {String message = "";_onStartScroll(ScrollMetrics metrics) {setState(() {message = "Scroll Start";});}_onUpdateScroll(ScrollMetrics metrics) {print(metrics.pixels);setState(() {message = "Scroll Update";});}_onEndScroll(ScrollMetrics metrics) {setState(() {message = "Scroll End";});}@overrideWidget build(BuildContext context) {return Scaffold(appBar: AppBar(title: Text("NotificationListener"),),body: Column(children: <Widget>[Container(height: 50.0,color: Colors.green,child: Center(child: Text(message),),),Expanded(child: NotificationListener<ScrollNotification>(onNotification: (scrollNotification) {if (scrollNotification is ScrollStartNotification) {_onStartScroll(scrollNotification.metrics);} else if (scrollNotification is ScrollUpdateNotification) {_onUpdateScroll(scrollNotification.metrics);} else if (scrollNotification is ScrollEndNotification) {_onEndScroll(scrollNotification.metrics);}},child: ListView.builder(itemCount: 30,itemBuilder: (context, index) {return ListTile(title: Text("Index : $index"));},),),),],),);}
}

9.GestureDetector实现360展物

效果图

效果图

关键代码

import 'dart:async';import 'package:flutter/material.dart';
class GestureDetectorPage extends StatefulWidget {GestureDetectorPage({Key key, this.title}) : super(key: key);final String title;@override_GestureDetectorPageState createState() => _GestureDetectorPageState();
}class _GestureDetectorPageState extends State<GestureDetectorPage> {int index = 1; // 第一张图片int count = 72; // 图片总数double initial = 0.0;final int DIRECTION_ANTICLOCKWISE = 1; // 逆时针final int DIRECTION_CLOCKWISE = -1; // 顺时针int direction;Timer _timer;@overridevoid initState() {super.initState();direction = DIRECTION_CLOCKWISE;_startTimer();}_startTimer() {_timer = Timer.periodic(new Duration(milliseconds: 90), (timer) {setState(() {});if (direction == DIRECTION_ANTICLOCKWISE) {if (index > 1) {index--;return;}// 重新回到第一张图index = count;} else if (direction == DIRECTION_CLOCKWISE) {if (index < count) {index++;return;}// 重新回到第一张图index = 1;}});}@overrideWidget build(BuildContext context) {var width = MediaQuery.of(context).size.width;var height = width;return Scaffold(appBar: AppBar(title: Text(widget.title),),body: Center(child: Column(mainAxisAlignment: MainAxisAlignment.center,children: <Widget>[GestureDetector(onTap: () => _cancelTimer(),onPanStart: (e) => _cancelTimer(),onPanUpdate: (e) => _onTouchImage(e),// 在触屏结束之后，恢复自动旋转onPanEnd: (e) => _startTimer(),child: Image.asset('assets/images/product00${index}.png',fit: BoxFit.cover,width: width,height: height,// 该属性防止图片快速切换时白屏发生，在新图出前时保持旧的图gaplessPlayback: true,excludeFromSemantics: true,),)],),),);}void _onTouchImage(e) {if (e.delta.dx < 0) {direction = DIRECTION_CLOCKWISE;}if (e.delta.dx > 0) {direction = DIRECTION_ANTICLOCKWISE;}setState(() {index -= e.delta.dx.toInt();});// 防止取到不存在的图片报错if (index < 1) index = 1;if (index > count) index = count;}@overridevoid dispose() {super.dispose();_cancelTimer();}void _cancelTimer() {_timer?.cancel();}
}

 

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作者：StevenHu_Sir
链接：https://www.jianshu.com/p/f7b51e7f1bda
来源：简书
著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

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