Flash Builder 开发AIR for Android(7) 重力感应

运动传感器，设备中有个板载的感应器，感应器中有个轴用来感应移动。如x轴，从左到右，y轴从下到上，z轴，从后到钱。

Accelerometer 类。

flash.sensors.Accelerometer 类是新增加的ActionScript 类，用来接收从感应发过来得数据。是EveDispatcher 类的子类。

flash.sensors.AccelerometerEvent 是一个新的事件，返回了感应器的更新的信息

//检查设备是否支持重力感应

import flash.sensors.Accelerometer;

if(Accelerometer.isSuppported==false)

{

return;

}

如果用户不启用重力感应，则Accelerometer 类的muted 属性为flase。

重力感应，需要设置初始化一个Accelerotmter 的一个对象，

//

private var accelerometer:Accelerometer;

accelerometer=new Accelerometer();

import flash.events.AccelerometerEvent;

accelerometer.addEventListener(AccelerometerEvent.UPDATE,onUpdate);

function onUpdate(event:AccelerometerEvent):void

{

trace(event.accelerationX)

trace(event.accelerationY)

trace(event.accelerationZ);

trace(event.timestamp);

}

//可视化的状态呈现

接下来的应用程序，我们将展示重力感应在x，y，z轴上的值。创建一个颜色的工具条，x是红色，y是绿色，z是蓝色。中间的垂直线代表了

0点或者是重置状态。

简单的动画：

我们来制作一个简单的沿着x和y轴的动画。我们将会移动这个ball，随着设备的移动。

public class SimpleBall extends Sprite

{

private const MULTIPLIER:Number = 8.0;

private var _accelerometer:Accelerometer;

private var _ball:Shape;

public function SimpleBall()

{

stage.align = StageAlign.TOP_LEFT;

stage.scaleMode = StageScaleMode.NO_SCALE;

init();

}

private function init():void

{

if (Accelerometer.isSupported)

{

_ball = new Shape();

var g:Graphics = _ball.graphics;

g.beginFill(0xFF9900);

g.drawCircle(0, 0, 50);

g.endFill();

_ball.x = stage.stageWidth * 0.5;

_ball.y = stage.stageHeight * 0.5;

_ball.cacheAsBitmap = true;

addChild(_ball);

_accelerometer = new Accelerometer();

_accelerometer.addEventListener(AccelerometerEvent.UPDATE, onUpdate);

}

}

private function onUpdate(event:AccelerometerEvent):void

{

_ball.x -= event.accelerationX * MULTIPLIER;

_ball.y += event.accelerationY * MULTIPLIER;

}

}

更新和渲染屏幕

边界

保持你的动画在屏幕的边界以内。设置边界当球儿的位置更新是改变他们。

public class Boundaries extends Sprite

{

private const MULTIPLIER:Number = 20.0;

private var _accelerometer:Accelerometer;

private var _vx:Number = 0.0;

private var _vy:Number = 0.0;

private var _ball:Shape;

private var _radius:int;

private var _xBounds:int;

private var _yBounds:int;

private var _newX:Number = 0.0;

private var _newY:Number = 0.0;

public function Boundaries()

{

stage.align = StageAlign.TOP_LEFT;

stage.scaleMode = StageScaleMode.NO_SCALE;

init();

}

private function init():void

{

if (Accelerometer.isSupported)

{

_ball = new Shape();

var g:Graphics = _ball.graphics;

g.beginFill(0xFF9900);

g.drawCircle(0, 0, 50);

g.endFill();

_ball.x = stage.stageWidth * 0.5;

_ball.y = stage.stageHeight * 0.5;

_ball.cacheAsBitmap = true;

addChild(_ball);

_radius = _ball.width;

_xBounds = stage.stageWidth - _radius;

_yBounds = stage.stageHeight - _radius;

_accelerometer = new Accelerometer();

_accelerometer.addEventListener(AccelerometerEvent.UPDATE, onUpdate);

stage.addEventListener(Event.ENTER_FRAME, onEnterFrame);

}

}

private function onUpdate(event:AccelerometerEvent):void

{

_vx = event.accelerationX * MULTIPLIER;

_vy = event.accelerationY * MULTIPLIER;

}

private function onEnterFrame(event:Event):void

{

_newX = _ball.x - _vx;

_newY = _ball.y + _vy;

if (_newX > _radius && _newX < _xBounds)

{

_ball.x = _newX;

}

if (_newY > _radius && _newY < _yBounds)

{

_ball.y = _newY;

}

}

围绕中心旋转：

public class RotateCenter extends Sprite

{

private const MULTIPLIER:Number = 10.0;

private var _accelerometer:Accelerometer;

private var _ball:Shape;

private var _radius:int;

private var _xBounds:int;

private var _yBounds:int;

private var _centerX:int;

private var _centerY:int;

private var _vx:Number = 0.0;

private var _vy:Number = 0.0;

private var _newX:Number = 0.0;

private var _newY:Number = 0.0;

public function RotateCenter()

{

stage.align = StageAlign.TOP_LEFT;

stage.scaleMode = StageScaleMode.NO_SCALE;

init();

}

private function init():void

{

if (Accelerometer.isSupported)

{

_ball = new Shape();

var g:Graphics = _ball.graphics;

g.beginFill(0xFF3300);

g.drawCircle(0, 0, 30);

g.beginFill(0xFFFF00);

g.drawCircle(10, 10, 10);

g.endFill();

_ball.x = stage.stageWidth * 0.5;

_ball.y = stage.stageHeight * 0.5;

_ball.cacheAsBitmap = true;

addChild(_ball);

_centerX = stage.stageWidth*0.5;

_centerY = stage.stageHeight*0.5;

_radius = _ball.width;

_xBounds = stage.stageWidth - _radius;

_yBounds = stage.stageHeight - _radius;

_accelerometer = new Accelerometer();

_accelerometer.addEventListener(AccelerometerEvent.UPDATE, onUpdate);

stage.addEventListener(Event.ENTER_FRAME, onEnterFrame);

}

}

private function onUpdate(event:AccelerometerEvent):void

{

_vx = event.accelerationX * MULTIPLIER;

_vy = event.accelerationY * MULTIPLIER;

}

private function onEnterFrame(event:Event):void

{

_newX = _ball.x - _vx;

_newY = _ball.y + _vy;

if (_newX > _radius && _newX < _xBounds)

{

_ball.x = _newX;

}

if (_newY > _radius && _newY < _yBounds)

{

_ball.y = _newY;

}

var dx:int = _centerX - _ball.x;

var dy:int = _centerY - _ball.y;

var radians:Number = Math.atan2(dy, dx);

_ball.rotation = radians*180/Math.PI;

}

}

震动：

震动设备是一个很常见的交互方式。你可以使用他来确定用户的强度，假设是一个真实的对象。

震动可以被定义为一个强烈的运动，关联了一个很大的值。这个例子中，当织大于边界值2.0 ，我们认为移动是一个震动。

public class Shake extends Sprite

{

private const THRESHOLD:Number = 1.5;

private var _accelerometer:Accelerometer;

private var _isMeasuring:Boolean = false;

private var _isShaking:Boolean = false;

public function Shake()

{

stage.align = StageAlign.TOP_LEFT;

stage.scaleMode = StageScaleMode.NO_SCALE;

init();

}

private function init():void

{

if (Accelerometer.isSupported)

{

trace("is supported");

_accelerometer = new Accelerometer();

_accelerometer.addEventListener(AccelerometerEvent.UPDATE, onUpdate);

}

}

private function onUpdate(event:AccelerometerEvent):void

{

if (_isMeasuring) {

return;

}

_isMeasuring = true;

trace("x", event.accelerationX);

trace("y", event.accelerationY);

trace("z", event.accelerationZ);

if (Math.abs(event.accelerationX) > THRESHOLD)

{

_isShaking = true;

}

if (Math.abs(event.accelerationY) > THRESHOLD*2)

{

_isShaking = true;

}

if (Math.abs(event.accelerationZ) > THRESHOLD*3)

{

_isShaking = true;

}

if (_isShaking)

{

trace("we have a shake");

}

_isMeasuring = false;

}

平滑的值