微信小程序开发之手势解锁代码实例

<!--index.wxml--><view>  <canvas></canvas></view>.gesture-lock {    margin: 100rpx auto;    width: 300px;    height: 300px;    background-color: #ffffff;}

    constructor(canvasid, context, cb, opt){        this.touchPoints = [];        this.checkPoints = [];        this.canvasid = canvasid;        this.ctx = context;        this.width = opt && opt.width || 300; //画布长度        this.height = opt && opt.height || 300; //画布宽度        this.cycleNum = opt && opt.cycleNum || 3;        this.radius = 0;  //触摸点半径        this.isParamOk = false;        this.marge = this.margeCircle = 25; //触摸点及触摸点和画布边界间隔        this.initColor = opt && opt.initColor || '#C5C5C3';           this.checkColor = opt && opt.checkColor || '#5AA9EC';        this.errorColor = opt && opt.errorColor || '#e19984';        this.touchState = "unTouch";        this.checkParam();        this.lastCheckPoint = null;        if (this.isParamOk) {            // 计算触摸点的半径长度            this.radius = (this.width - this.marge * 2 - (this.margeCircle * (this.cycleNum - 1))) / (this.cycleNum * 2)            this.radius = Math.floor(this.radius);            // 计算每个触摸点的圆心位置            this.calCircleParams();        }        this.onEnd = cb; //滑动手势结束时的回调函数    }

    calCircleParams() {        let n = this.cycleNum;        let count = 0;        for (let i = 0; i <p><strong>绘制手势锁</strong></p><pre class="brush:js;toolbar:false;">     for (let i = 0; i <p>接下来就是识别用户的滑动行为，判断用户划过了哪些圆圈，进而识别出用户的手势。</p><p><strong>在touchstart和touchmove事件中检测触发并更新画布</strong></p><pre class="brush:js;toolbar:false;"><p style="margin-bottom: 7px; margin-top: 14px;">   onTouchStart(e) {<br>        // 不识别多点触控<br>        if (e.touches.length &gt; 1){<br>            this.touchState = "unTouch";<br>            return;<br>        }<br>        this.touchState = "startTouch";<br>        this.checkTouch(e);<br>        let point = {x:e.touches[0].x, y:e.touches[0].y};<br>        this.drawCanvas(this.checkColor, point);<br>    }<br><br>    onTouchMove(e) {<br>        if (e.touchState === "unTouch") {<br>            return;<br>        }<br>        if (e.touches.length &gt; 1){<br>            this.touchState = "unTouch";<br>            return;<br>        }<br>        this.checkTouch(e);<br>        let point = {x:e.touches[0].x, y:e.touches[0].y};<br>        this.drawCanvas(this.checkColor, point);<br>    }<br></p>

    checkTouch(e) {        for (let i = 0; i <p><strong>更新画布</strong></p><pre class="brush:js;toolbar:false;">     drawCanvas(color, point) {        //每次更新之前先清空画布        this.ctx.clearRect(0, 0, this.width, this.height);        //使用不同颜色和形式绘制已触发和未触发的锁        for (let i = 0; i  1) {             let lastPoint = this.checkPoints[0];             for (let i = 1; i <p><strong>当用户滑动结束时调用回调函数并传递识别出的手势</strong></p><pre class="brush:js;toolbar:false;">    onTouchEnd(e) {        typeof this.onEnd === 'function' &amp;&amp; this.onEnd(this.checkPoints, false);    }    onTouchCancel(e) {        typeof this.onEnd === 'function' &amp;&amp; this.onEnd(this.checkPoints, true);    }

    gestureError() {        this.drawCanvas(this.errorColor)    }    reset() {        for (let i = 0; i <p><strong>如何调用</strong><br>在onload方法中创建lock对象并在用户触摸事件中调用相应方法</p><pre class="brush:js;toolbar:false;">  onLoad: function () {    var s = this;    this.lock = new Lock("id-gesture-lock", wx.createCanvasContext("id-gesture-lock"), function(checkPoints, isCancel) {      console.log('over');      s.lock.gestureError();      setTimeout(function() {        s.lock.reset();      }, 1000);    }, {width:300, height:300})    this.lock.drawGestureLock();    console.log('onLoad')    var that = this      //调用应用实例的方法获取全局数据    app.getUserInfo(function(userInfo){      //更新数据      that.setData({        userInfo:userInfo      })      that.update()    })  },  onTouchStart: function (e) {    this.lock.onTouchStart(e);  },  onTouchMove: function (e) {    this.lock.onTouchMove(e);  },  onTouchEnd: function (e) {    this.lock.onTouchEnd(e);  }