微信小程序实现手势图案锁屏功能

<view class="container">  <view class="reset" bindtap="resetPwd">重置密码</view>  <view class="title">{{title}}</view>  <canvas canvas-id="canvas" class="canvas" bindtouchend="onTouchEnd"   bindtouchstart="onTouchStart" bindtouchmove="onTouchMove"></canvas></view>

var Locker = class { constructor(page,opt){  var obj = opt || {};  this.page = page;  this.width = obj.width || 300;  this.height = obj.height || 300;  this.canvasId = obj.id || 'canvas';  this.cleColor = obj.cleColor || '#CFE6FF';  this.cleCenterColor = obj.cleCenterColor || '#CFE6FF';  var chooseType = obj.chooseType || 3;  // 判断是否缓存有chooseType，有就用缓存，没有就用传入的值  this.chooseType = Number(wx.getStorageSync('chooseType')) || chooseType;  this.init(); } init(){  this.pswObj = wx.getStorageSync('passwordxx') ? {   step: 2,   spassword: JSON.parse(wx.getStorageSync('passwordxx'))  } : {};  this.makeState();  // 创建 canvas 绘图上下文（指定 canvasId）  this.ctx = wx.createCanvasContext(this.canvasId,this);  this.touchFlag = false;  this.lastPoint = [];  // 绘制圆  this.createCircle();  // canvas绑定事件  this.bindEvent(); } makeState() {  if (this.pswObj.step == 2) {   this.page.setData({ title:'请解锁'});  } else if (this.pswObj.step == 1) {   // pass  } else {   // pass  } } // 画圆方法 drawCle(x,y){  // 设置边框颜色。  this.ctx.setStrokeStyle(this.cleColor); // 注意用set  // 设置线条的宽度。  this.ctx.setLineWidth(2); // 注意用set  // 开始创建一个路径，需要调用fill或者stroke才会使用路径进行填充或描边。  this.ctx.beginPath();  // 画一条弧线。  this.ctx.arc(x, y, this.r, 0, Math.PI * 2, true);  // 关闭一个路径  this.ctx.closePath();  // 画出当前路径的边框。默认颜色色为黑色。  this.ctx.stroke();  // 将之前在绘图上下文中的描述（路径、变形、样式）画到 canvas 中。  this.ctx.draw(true); } // 计算两点之间的距离的方法 getDis(a, b) {  return Math.sqrt(Math.pow(a.x - b.x, 2) + Math.pow(a.y - b.y, 2)); } // 创建解锁点的坐标，根据canvas的大小（默认300px）来平均分配半径 createCircle() {  var n = this.chooseType;  var count = 0;  // 计算圆半径  this.r = this.width / (2 + 4 * n);  this.arr = [];  this.restPoint = [];  var r = this.r;  // 获取圆心坐标，以及当前圆所代表的数  for (var i = 0; i < n; i++) {   for (var j = 0; j < n; j++) {    count++;    var obj = {     x: j * 4 * r + 3 * r,     y: i * 4 * r + 3 * r,     index: count    };    this.arr.push(obj);    this.restPoint.push(obj);   }  }  // 清空画布  this.ctx.clearRect(0, 0, this.width, this.height);  // 绘制所有的圆  this.arr.forEach(current => {this.drawCle(current.x, current.y);}); } // 设置密码绘制 getPosition(e) { // 获取touch点相对于canvas的坐标  var po = {   x: e.touches[0].x,   y: e.touches[0].y  };  return po; } precisePosition(po){  var arr = this.restPoint.filter(current => Math.abs(po.x - current.x) < this.r && Math.abs(po.y - current.y) < this.r);  return arr[0]; } drawPoint(obj) { // 初始化圆心  for (var i = 0; i < this.lastPoint.length; i++) {   this.ctx.setFillStyle(this.cleCenterColor); // 注意用set方法   this.ctx.beginPath();   this.ctx.arc(this.lastPoint[i].x, this.lastPoint[i].y, this.r / 2, 0, Math.PI * 2, true);   this.ctx.closePath();   this.ctx.fill();   this.ctx.draw(true);  } } drawLine(po) {// 解锁轨迹  this.ctx.beginPath();  this.ctx.lineWidth = 3;  this.ctx.moveTo(this.lastPoint[0].x,this.lastPoint[0].y);  for (var i = 1; i < this.lastPoint.length; i++) {   this.ctx.lineTo(this.lastPoint[i].x, this.lastPoint[i].y);  }  this.ctx.lineTo(po.x, po.y);  this.ctx.stroke();  this.ctx.closePath();  this.ctx.draw(true); } pickPoints(fromPt, toPt) {  var lineLength = this.getDis(fromPt, toPt);  var dir = toPt.index > fromPt.index ? 1 : -1;  var len = this.restPoint.length;  var i = dir === 1 ? 0 : (len - 1);  var limit = dir === 1 ? len : -1;  while (i !== limit) {   var pt = this.restPoint[i];   if (this.getDis(pt, fromPt) + this.getDis(pt, toPt) === lineLength) {    this.drawPoint(pt.x, pt.y);    this.lastPoint.push(pt);    this.restPoint.splice(i, 1);    if (limit > 0) {     i--;     limit--;    }   }   i += dir;  } } update(po) {// 核心变换方法在touchmove时候调用  this.ctx.clearRect(0, 0, this.width, this.height);  for (var i = 0; i < this.arr.length; i++) { // 每帧先把面板画出来   this.drawCle(this.arr[i].x, this.arr[i].y);  }  this.drawPoint(this.lastPoint);// 每帧花轨迹  this.drawLine(po, this.lastPoint);// 每帧画圆心  for (var i = 0; i < this.restPoint.length; i++) {   var pt = this.restPoint[i];   if (Math.abs(po.x - pt.x) < this.r && Math.abs(po.y - pt.y) < this.r) {    this.drawPoint(pt.x, pt.y);    this.pickPoints(this.lastPoint[this.lastPoint.length - 1], pt);    break;   }  } } checkPass(psw1, psw2) {// 检测密码  var p1 = '',   p2 = '';  for (var i = 0; i < psw1.length; i++) {   p1 += psw1[i].index + psw1[i].index;  }  for (var i = 0; i < psw2.length; i++) {   p2 += psw2[i].index + psw2[i].index;  }  return p1 === p2; } storePass(psw) {// touchend结束之后对密码和状态的处理  if (this.pswObj.step == 1) {   if (this.checkPass(this.pswObj.fpassword, psw)) {    this.pswObj.step = 2;    this.pswObj.spassword = psw;    this.page.setData({title:'密码保存成功'});    this.drawStatusPoint('#2CFF26');    wx.setStorageSync('passwordxx', JSON.stringify(this.pswObj.spassword));    wx.setStorageSync('chooseType', this.chooseType);   } else {    this.page.setData({ title: '两次不一致，重新输入' });    this.drawStatusPoint('red');    delete this.pswObj.step;   }  } else if (this.pswObj.step == 2) {   if (this.checkPass(this.pswObj.spassword, psw)) {    this.page.setData({ title: '解锁成功' });    this.drawStatusPoint('#2CFF26');   } else {    this.drawStatusPoint('red');    this.page.setData({ title: '解锁失败' });   }  } else {   this.pswObj.step = 1;   this.pswObj.fpassword = psw;   this.page.setData({ title: '再次输入' });  } } drawStatusPoint(type) { // 初始化状态线条  for (var i = 0; i < this.lastPoint.length; i++) {   this.ctx.strokeStyle = type;   this.ctx.beginPath();   this.ctx.arc(this.lastPoint[i].x, this.lastPoint[i].y, this.r, 0, Math.PI * 2, true);   this.ctx.closePath();   this.ctx.stroke();   this.ctx.draw(true);  } } updatePassword() {  wx.removeStorageSync('passwordxx');  wx.removeStorageSync('chooseType');  this.pswObj = {};  this.page.setData({ title: '绘制解锁图案' });  this.reset(); } reset() {  this.makeState();  this.createCircle(); } bindEvent(){  var self = this;  this.page.onTouchStart = function(e){   var po = self.getPosition(e);   self.lastPoint = [];   for (var i = 0; i < self.arr.length; i++) {    if (Math.abs(po.x - self.arr[i].x) < self.r && Math.abs(po.y - self.arr[i].y) < self.r) {     self.touchFlag = true;     self.drawPoint(self.arr[i].x, self.arr[i].y);     self.lastPoint.push(self.arr[i]);     self.restPoint.splice(i, 1);     break;    }   }  }  this.page.onTouchMove = function(e){   if (self.touchFlag) {    self.update(self.getPosition(e));   }  }  this.page.onTouchEnd = function(e){   if (self.touchFlag) {    self.touchFlag = false;    self.storePass(self.lastPoint);    setTimeout(function () {     self.reset();    }, 300);   }  } }}module.exports = Locker;