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  对于如何用微信小程序开发手势解锁?还不明白的朋友们，一起来看看小编为大家准备的这篇教程吧。

  整个功能基于canvas实现，首先添加画布组件，并设定样式

  

  

  

  bindtouchmove="onTouchMove" bindtouchend="onTouchEnd">

  

  .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 < this.touchPoints.length; i++){

  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 = 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);

  }

  以上就是如何用微信小程序开发手势解锁的全部内容了，大家都学会了吗?

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