怎么在html5中使用canvas实现手势解锁？针对这个问题，这篇文章详细介绍了相对应的分析和解答，希望可以帮助更多想解决这个问题的小伙伴找到更简单易行的方法。
demo.html
<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no"> <title>手势解锁</title> <style type="text/css"> body{ text-align: center; background: #305066; } h5{ color: #22C3AA; } </style></head><body> <script type="text/javascript" src="src/index.js"></script> <script type="text/javascript"> // 1、生成背景 // 2、title生成 // 3、用js动态生成canvas标签 // 4、js方式动态生成h5标签和canvas标签 new canvasLock({chooseType:3}).init(); </script></body></html>index.js
(function(){ window.canvasLock = function(obj){ this.height = obj.height; this.width = obj.width; this.chooseType = obj.chooseType; }; // js方式动态生成dom canvasLock.prototype.initDom = function(){ var wrap = document.createElement('div'); var str = '<h5 id="title" class="title">绘制解锁图案</h5>'; wrap.setAttribute('style','position: absolute;top:0;left:0;right:0;bottom:0;'); var canvas = document.createElement('canvas'); canvas.setAttribute('id','canvas'); canvas.style.cssText = 'background-color: #305066;display: inline-block;margin-top: 15px;'; wrap.innerHTML = str; wrap.appendChild(canvas); var width = this.width || 300; var height = this.height || 300; document.body.appendChild(wrap); // 高清屏锁放 canvas.style.width = width + "px"; canvas.style.height = height + "px"; canvas.width = width; canvas.height = height; } canvasLock.prototype.drawCle = function(x, y) { // 初始化解锁密码面板 this.ctx.strokeStyle = '#CFE6FF'; this.ctx.lineWidth = 2; this.ctx.beginPath(); this.ctx.arc(x, y, this.r, 0, Math.PI * 2, true); this.ctx.closePath(); this.ctx.stroke(); } canvasLock.prototype.createCircle = function() {// 创建解锁点的坐标，根据canvas的大小来平均分配半径 var n = this.chooseType; var count = 0; this.r = this.ctx.canvas.width / (2 + 4 * n);// 公式计算 this.lastPoint = []; this.arr = []; this.restPoint = []; var r = this.r; 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); } } this.ctx.clearRect(0, 0, this.ctx.canvas.width, this.ctx.canvas.height); for (var i = 0 ; i < this.arr.length ; i++) { // 画圆函数 this.drawCle(this.arr[i].x, this.arr[i].y); } //return arr; } // 程序初始化 canvasLock.prototype.init = function() { this.initDom(); this.canvas = document.getElementById('canvas'); this.ctx = this.canvas.getContext('2d'); this.touchFlag = false; // 1、确定半径 // 2、确定每一个圆的中心坐标点 // 3、一行3个圆14个半径，一行4个圆有18个半径 this.createCircle(); this.bindEvent(); } canvasLock.prototype.bindEvent = function(){ var self = this; this.canvas.addEventListener("touchstart", function (e) { // 2、touchstart判断是否点击的位置处于圆内getPosition，处于则初始化 // * lastpoint、restPoint // po有x和y，并且是相较于canvas边距 var po = self.getPosition(e); console.log(po.x) // 判断是否在圆内的原理：多出来的这条 x/y < r 在圆内 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; // lastPoint存放的就是选中的圆圈的x/y坐标值 self.lastPoint.push(self.arr[i]); self.restPoint.splice(i,1); break; } } }, false); this.canvas.addEventListener("touchmove", function (e) { // touchmove做的就是：画圆drawPoint和划线drawLine if (self.touchFlag) { self.update(self.getPosition(e)); } }, false); this.canvas.addEventListener("touchend", function(e){ if (self.touchFlag) { self.storePass(self.lastPoint); setTimeout(function(){ self.reset(); }, 300); } }, false); } canvasLock.prototype.getPosition = function(e) {// 获取touch点相对于canvas的坐标 var rect = e.currentTarget.getBoundingClientRect(); var po = { x: (e.touches[0].clientX - rect.left), y: (e.touches[0].clientY - rect.top) }; return po; } canvasLock.prototype.update = function(po) {// 核心变换方法在touchmove时候调用 this.ctx.clearRect(0, 0, this.ctx.canvas.width, this.ctx.canvas.height); // 重新画9个圆圈 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();// 画圆 this.drawLine(po);// 画线 // 1、检测手势移动的位置是否处于下一个圆内 // 2、圆内的话则画圆 drawPoint // 3、已经画过实心圆的圆，无需重复检测 for (var i = 0 ; i < this.restPoint.length ; i++) { if (Math.abs(po.x - this.restPoint[i].x) < this.r && Math.abs(po.y - this.restPoint[i].y) < this.r) { this.drawPoint(); this.lastPoint.push(this.restPoint[i]); this.restPoint.splice(i, 1); break; } } console.log(this.lastPoint) } canvasLock.prototype.drawLine = function(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(); } canvasLock.prototype.drawPoint = function() { // 初始化圆心 for (var i = 0 ; i < this.lastPoint.length ; i++) { this.ctx.fillStyle = '#CFE6FF'; 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(); } } // 1、检测路径是否是对的 // 2、如果是对的就重置，圆圈变绿 // 3、不对也重置，圆圈变红 // 4、重置 canvasLock.prototype.storePass = function() { if (this.checkPass()) { document.getElementById('title').innerHTML = '解锁成功'; this.drawStatusPoint('#2CFF26'); }else{ document.getElementById('title').innerHTML = '解锁失败'; this.drawStatusPoint('red'); } } canvasLock.prototype.checkPass = function() { var p1 = '123', p2 = ''; for (var i = 0 ; i < this.lastPoint.length ; i++) { p2 += this.lastPoint[i].index; } return p1 === p2; } canvasLock.prototype.drawStatusPoint = function(type) { 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(); } } canvasLock.prototype.reset = function(){ this.createCircle(); }})();关于怎么在html5中使用canvas实现手势解锁问题的解答就分享到这里了，希望以上内容可以对大家有一定的帮助，如果你还有很多疑惑没有解开，可以关注编程网行业资讯频道了解更多相关知识。
