canvas+js生成驗證碼 vue元件
阿新 • • 發佈:2020-11-27
vue腳手架
<template> <div class="s-canvas"> <canvas id="s-canvas" :width="contentWidth" :height="contentHeight"></canvas> </div> </template> <script> const who = '1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ'; export default{ name: 'SIdentify', props: { identifyCode: { //預設註冊碼 type: String, default: '' }, fontSizeMin: { // 字型最小值 type: Number, default: 25 }, fontSizeMax: { // 字型最大值 type: Number, default: 35 }, backgroundColorMin: { // 驗證碼圖片背景色最小值 type: Number, default: 200 }, backgroundColorMax: { // 驗證碼圖片背景色最大值 type: Number, default: 220 }, dotColorMin: { // 背景干擾點最小值 type: Number, default: 60 }, dotColorMax: { // 背景干擾點最大值 type: Number, default: 120 }, contentWidth: { //容器寬度 type: Number, default: 105 }, contentHeight: { //容器高度 type: Number, default: 38 } }, methods: { // 生成一個隨機數 randomNum (min, max) { return Math.floor(Math.random() * (max - min) + min) }, // 生成一個隨機的顏色 randomColor (min, max) { let r = this.randomNum(min, max) let g = this.randomNum(min, max) let b = this.randomNum(min, max) return 'rgb(' + r + ',' + g + ',' + b + ')' }, drawPic () { let canvas = document.getElementById('s-canvas') let ctx = canvas.getContext('2d') ctx.textBaseline = 'bottom' // 繪製背景 ctx.fillStyle = this.randomColor(this.backgroundColorMin, this.backgroundColorMax) ctx.fillRect(0, 0, this.contentWidth, this.contentHeight) // 繪製文字 for (let i = 0; i < this.identifyCode.length; i++) { this.drawText(ctx, this.identifyCode[i], i) } this.drawLine(ctx) this.drawDot(ctx) }, drawText (ctx, txt, i) { ctx.fillStyle = this.randomColor(50, 160) //隨機生成字型顏色 ctx.font = this.randomNum(this.fontSizeMin, this.fontSizeMax) + 'px SimHei' //隨機生成字型大小 let x = (i + 1) * (this.contentWidth / (this.identifyCode.length + 1)) let y = this.randomNum(this.fontSizeMax, this.contentHeight - 5) var deg = this.randomNum(-30, 30) // 修改座標原點和旋轉角度 ctx.translate(x, y) ctx.rotate(deg * Math.PI / 180) ctx.fillText(txt, 0, 0) // 恢復座標原點和旋轉角度 ctx.rotate(-deg * Math.PI / 180) ctx.translate(-x, -y) }, drawLine (ctx) { // 繪製干擾線 for (let i = 0; i < 4; i++) { ctx.strokeStyle = this.randomColor(100, 200) ctx.beginPath() ctx.moveTo(this.randomNum(0, this.contentWidth), this.randomNum(0, this.contentHeight)) ctx.lineTo(this.randomNum(0, this.contentWidth), this.randomNum(0, this.contentHeight)) ctx.stroke() } }, drawDot (ctx) { // 繪製干擾點 for (let i = 0; i < 30; i++) { ctx.fillStyle = this.randomColor(0, 255) ctx.beginPath() ctx.arc(this.randomNum(0, this.contentWidth), this.randomNum(0, this.contentHeight), 1, 0, 2 * Math.PI) ctx.fill() } }, makeCode(o, l) { for (let i = 0; i < l; i++) { this.identifyCode=this.identifyCode+''+o[this.randomNum(0, o.length)]; } this.drawPic(); this.$emit('code',res); } }, mounted () { this.makeCode(who,4) } } </script>