手势解锁是app上常见的解锁方式，相比输入密码方式操作起来要方便许多。这篇文章主要介绍了微信小程序开发教程-手势解锁实例，有兴趣的可以了解一下。
手势解锁是app上常见的解锁方式，相比输入密码方式操作起来要方便许多。下面展示如何基于微信小程序实现手机解锁。最终实现效果如下图:
整个功能基于canvas实现，首先添加画布组件，并设定样式
.gesture-lock { margin: 100rpx auto; width: 300px; height: 300px; background-color: #ffffff; }
手势解锁实现代码在gesture_lock.js中(完整源码地址见末尾)。
初始化
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 }
主要设置一些参数，如canvas的长宽，canvas的context，手势锁的个数(3乘3, 4乘4)，手势锁的颜色，手势滑动结束时的回调函数等。并计算出手势锁的半径。
计算每个手势锁的圆心位置
calCircleParams() { let n = this.cycleNum; let count = 0; for (let i = 0; i <n; i++) { for (let j = 0; j <n; j++){ count++; let touchPoint = { x: this.marge + i * (this.radius * 2 + this.margeCircle) + this.radius, y: this.marge + j * (this.radius * 2 + this.margeCircle) + this.radius, index: count, check: "uncheck", } this.touchPoints.push(touchPoint) } } }
绘制手势锁
for (let i = 0; i <this.touchPoints.length; i++){ this.drawCircle(this.touchPoints[i].x, this.touchPoints[i].y, this.radius, this.initColor) } this.ctx.draw(true);
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。
在touchstart和touchmove事件中检测触发并更新画布
onTouchStart(e) { // 不识别多点触控 if (e.touches.length > 1){ this.touchState = "unTouch"; return; } this.touchState = "startTouch"; this.checkTouch(e); let point = {x:e.touches[0].x, y:e.touches[0].y}; this.drawCanvas(this.checkColor, point); } onTouchMove(e) { if (e.touchState === "unTouch") { return; } if (e.touches.length > 1){ this.touchState = "unTouch"; return; } this.checkTouch(e); let point = {x:e.touches[0].x, y:e.touches[0].y}; this.drawCanvas(this.checkColor, point); }
检测用户是否划过某个圆圈
checkTouch(e) { for (let i = 0; i <this.touchPoints.length; i++){ let point = this.touchPoints[i]; if (isPointInCycle(e.touches[0].x, e.touches[0].y, point.x, point.y, this.radius)) { if (point.check === 'uncheck') { this.checkPoints.push(point); this.lastCheckPoint = point; } point.check = "check" return; } } }
更新画布
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 <this.checkPoints.length; i++) { this.drawLine(lastPoint, this.checkPoints[i], color); lastPoint = this.checkPoints[i]; } } //绘制最后一个识别锁和当前触摸点之间的线段 if (this.lastCheckPoint && point) { this.drawLine(this.lastCheckPoint, point, color); } this.ctx.draw(true); }
当用户滑动结束时调用回调函数并传递识别出的手势
onTouchEnd(e) { typeof this.onEnd === 'function' && this.onEnd(this.checkPoints, false); } onTouchCancel(e) { typeof this.onEnd === 'function' && this.onEnd(this.checkPoints, true); }
重置和显示手势错误
gestureError() { this.drawCanvas(this.errorColor) } reset() { for (let i = 0; i <this.touchPoints.length; i++) { this.touchPoints[i].check = 'uncheck'; } this.checkPoints = []; this.lastCheckPoint = null; this.drawCanvas(this.initColor); }
如何调用
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
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); }
源码地址:源码下载
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