详见如者孙下：
canvas使用：
index.wxml中
js中
整个功能基于canvas实现，首先添加画布组件，并设定样式<!--index.wxml--><view class="container">
<canvas canvas-id="id-gesture-lock" class="gesture-lock" bindtouchstart="onTouchStart"
bindtouchmove="onTouchMove" bindtouchend="onTouchEnd"></canvas></view>.gesture-lock {
margin: 100rpx auto
width: 300px
height: 300px
background-color: #ffffff
}123456789101112
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//画布宽度族毕
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 || '陆厅#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
}1234567891011121314151617181920212223242526
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。
计算每个手早穗隐势锁的圆心位置
calCircleParams() {let n = this.cycleNum let count = 0 for (let i = 0i <ni++) {for (let j = 0j <nj++){
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)
}
}
}1234567891011121314151617
绘制手势锁
for (let i = 0i <this.touchPoints.lengthi++){this.drawCircle(this.touchPoints[i].x, this.touchPoints[i].y, this.radius, this.initColor)
} this.ctx.draw(true)1234
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)
}123456789101112131415161718192021222324
检测用户是否划过某个圆圈
checkTouch(e) {for (let i = 0i <this.touchPoints.lengthi++){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
}
}
}12345678910111213
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 = 0i <this.touchPoints.lengthi++){let point = this.touchPoints[i] if (point.check === "check") {this.drawCircle(point.x, point.y, this.radius, color) this.drawCircleCentre(point.x, point.y, color)
}else {this.drawCircle(this.touchPoints[i].x, this.touchPoints[i].y, this.radius, this.initColor)
}
}//绘制已识别锁之间的线段
if (this.checkPoints.length >1) { let lastPoint = this.checkPoints[0]for (let i = 1i <this.checkPoints.lengthi++) { 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)
}12345678910111213141516171819202122232425262728
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)
}1234567
重置和显示手势错误
gestureError() {this.drawCanvas(this.errorColor)
}
reset() {for (let i = 0i <this.touchPoints.lengthi++) {this.touchPoints[i].check = 'uncheck'
}this.checkPoints = [] this.lastCheckPoint = null this.drawCanvas(this.initColor)
}123456789101112
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)
}
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