Flutter传感器

• AccelerometerEvent：描述设备的速度，包括重力的影响。可用于判断设备是否向特定方向移动
• UserAccelerometerEvent：描述设备的速度，但不包括重力。它通常被认为是用户对设备的影响
• GyroscopeEvent：描述设备的旋转

import 'package:sensors_plus/sensors_plus.dart';  accelerometerEvents.listen((AccelerometerEvent event) {   print(event); }); // [AccelerometerEvent (x: 0.0, y: 9.8, z: 0.0)]  userAccelerometerEvents.listen((UserAccelerometerEvent event) {   print(event); }); // [UserAccelerometerEvent (x: 0.0, y: 0.0, z: 0.0)]  gyroscopeEvents.listen((GyroscopeEvent event) {   print(event); }); // [GyroscopeEvent (x: 0.0, y: 0.0, z: 0.0)] 

分析：首先利用全局key获取紫色边框(容器)的坐标，然后根据重力感应不断修改加号图标的位置。

AccelerometerEvent? acceleration; late Timer _timer; /// 容器的key GlobalKey containerKey = GlobalKey(); /// 容器的xy界限 late RenderBox containerRenderBox; var containerOffset; var containerLeftX = 0.0, containerRightX = 0.0, containerTopY = 0.0, containerBottomY = 0.0;  /// 加号的key GlobalKey anchorKey = GlobalKey(); /// 加号的xy界限 late RenderBox anchorRenderBox; var anchorOffset; var anchorLeftX = 0.0, anchorRightX = 0.0, anchorTopY = 0.0, anchorBottomY = 0.0; /// 加号偏移量 var dx = 0.0.obs , dy = 0.0.obs; /// GETx特性 

部分加号组件代码

Obx(()=>Transform.translate(   key: anchorKey,   offset: Offset(dx.value, 0), /// 不需要在线环境dy所以去掉了操作，可添加使用   child: Image.asset(     R.imagesPlanIconAdd,     width: 52.dp,   ) )) 

部分容器组件代码

/// 容器是白色的Container覆盖到紫色Container，形成的环，所以要把它放在key放在白色Container上 Container(   key: controller.containerKey,   decoration: BoxDecoration(     color: c_FF,     borderRadius: BorderRadius.all(       Radius.circular(30.0),     ),   ), ) 

假设容器和加号图标已绑定相应的key。

accelerometerEvents.listen((AccelerometerEvent event) {   acceleration = event; });  _timer = Timer.periodic(const Duration(milliseconds: 10), (_) {   /// 该段主要用于获取容器的边界坐标   if(containerOffset == null && containerKey.currentContext != null){ /// 第一次进入页面时，会出现空值，所以不操作     containerRenderBox = containerKey.currentContext!.findRenderObject() as RenderBox;     containerOffset =  containerRenderBox.localToGlobal(Offset.zero);      containerLeftX = containerOffset?.dx;     containerRightX = containerOffset?.dx;     containerRightX = containerOffset?.dx   containerRenderBox.size.width;     containerTopY = containerOffset?.dy;     containerBottomY = containerOffset?.dy   containerRenderBox.size.height;   }    /// 该段主要用于获取加号边界坐标   if(anchorOffset == null && anchorKey.currentContext != null){     anchorRenderBox = anchorKey.currentContext!.findRenderObject() as RenderBox;     anchorOffset =  anchorRenderBox.localToGlobal(Offset.zero);      anchorLeftX = anchorOffset?.dx;     anchorRightX = anchorOffset?.dx   anchorRenderBox.size.width;     anchorTopY = anchorOffset?.dy;     anchorBottomY = anchorOffset?.dy   anchorRenderBox.size.height;   }    /// 刷新加号位置   if(acceleration != null && containerOffset != null && anchorOffset != null){     var dxNow = acceleration!.x.abs() < 1.0       ? dx.value : ((anchorLeftX   (dx.value - acceleration!.x)) > containerLeftX) && (anchorRightX   (dx.value - acceleration!.x)) < containerRightX ? dx.value - acceleration!.x : dx.value;     var dyNow = acceleration!.y.abs() < 1.0       ? dy.value : ((anchorTopY   (dy.value   acceleration!.y)) > containerTopY) && (anchorBottomY   (dy.value   acceleration!.y)) < containerBottomY ? dy.value   acceleration!.y : dy.value;     dx.value = dxNow;     dy.value = dyNow;   } }); 

??：因为我用的GETx因此，当将状态管理框架包裹在容器外时Obx(()=>Container())可自动刷新。如果不使用，则需要setState(() {})刷新组件。