基于canvas绘制的，Vue 图形验证码组件

一、组件代码

  1 <template>
  2   <div class="s-canvas">
  3     <canvas id="s-canvas" :width="contentWidth" :height="contentHeight"></canvas>
  4   </div>
  5 </template>
  6 <script>
  7   export default{
  8     name: 'SIdentify',
  9     props: {
 10       identifyCode: {
 11         type: String,
 12         default: '1234'
 13       },
 14       fontSizeMin: {
 15         type: Number,
 16         default: 20
 17       },
 18       fontSizeMax: {
 19         type: Number,
 20         default: 35
 21       },
 22       backgroundColorMin: {
 23         type: Number,
 24         default: 180
 25       },
 26       backgroundColorMax: {
 27         type: Number,
 28         default: 240
 29       },
 30       colorMin: {
 31         type: Number,
 32         default: 50
 33       },
 34       colorMax: {
 35         type: Number,
 36         default: 160
 37       },
 38       lineColorMin: {
 39         type: Number,
 40         default: 40
 41       },
 42       lineColorMax: {
 43         type: Number,
 44         default: 180
 45       },
 46       dotColorMin: {
 47         type: Number,
 48         default: 0
 49       },
 50       dotColorMax: {
 51         type: Number,
 52         default: 255
 53       },
 54       contentWidth: {
 55         type: Number,
 56         default: 112
 57       },
 58       contentHeight: {
 59         type: Number,
 60         default: 38
 61       }
 62     },
 63     methods: {
 64       // 生成一个随机数
 65       randomNum (min, max) {
 66         return Math.floor(Math.random() * (max - min) + min)
 67       },
 68       // 生成一个随机的颜色
 69       randomColor (min, max) {
 70         let r = this.randomNum(min, max)
 71         let g = this.randomNum(min, max)
 72         let b = this.randomNum(min, max)
 73         return 'rgb(' + r + ',' + g + ',' + b + ')'
 74       },
 75       drawPic () {
 76         let canvas = document.getElementById('s-canvas')
 77         let ctx = canvas.getContext('2d')
 78         ctx.textBaseline = 'bottom'
 79         // 绘制背景
 80         ctx.fillStyle = this.randomColor(this.backgroundColorMin, this.backgroundColorMax)
 81         ctx.fillRect(0, 0, this.contentWidth, this.contentHeight)
 82         // 绘制文字
 83         for (let i = 0; i < this.identifyCode.length; i++) {
 84           this.drawText(ctx, this.identifyCode[i], i)
 85         }
 86         this.drawLine(ctx)
 87         this.drawDot(ctx)
 88       },
 89       drawText (ctx, txt, i) {
 90         ctx.fillStyle = this.randomColor(this.colorMin, this.colorMax)
 91         ctx.font = this.randomNum(this.fontSizeMin, this.fontSizeMax) + 'px SimHei'
 92         let x = (i + 1) * (this.contentWidth / (this.identifyCode.length + 1))
 93         let y = this.randomNum(this.fontSizeMax, this.contentHeight - 5)
 94         var deg = this.randomNum(-45, 45)
 95         // 修改坐标原点和旋转角度
 96         ctx.translate(x, y)
 97         ctx.rotate(deg * Math.PI / 180)
 98         ctx.fillText(txt, 0, 0)
 99         // 恢复坐标原点和旋转角度
100         ctx.rotate(-deg * Math.PI / 180)
101         ctx.translate(-x, -y)
102       },
103       drawLine (ctx) {
104         // 绘制干扰线
105         for (let i = 0; i < 3; i++) {
106           ctx.strokeStyle = this.randomColor(this.lineColorMin, this.lineColorMax)
107           ctx.beginPath()
108           ctx.moveTo(this.randomNum(0, this.contentWidth), this.randomNum(0, this.contentHeight))
109           ctx.lineTo(this.randomNum(0, this.contentWidth), this.randomNum(0, this.contentHeight))
110           ctx.stroke()
111         }
112       },
113       drawDot (ctx) {
114         // 绘制干扰点
115         for (let i = 0; i < 30; i++) {
116           ctx.fillStyle = this.randomColor(0, 255)
117           ctx.beginPath()
118           ctx.arc(this.randomNum(0, this.contentWidth), this.randomNum(0, this.contentHeight), 1, 0, 2 * Math.PI)
119           ctx.fill()
120         }
121       }
122     },
123     watch: {
124       identifyCode () {
125         this.drawPic()
126       }
127     },
128     mounted () {
129       this.drawPic()
130     }
131   }
132 </script>

二、使用

js 部分：

 1 import SIdentify from "../../components/common/Identify/identify";
 2 export default {
 3   components: {
 4     SIdentify: SIdentify
 5   },
 6   data() {
 7     return {
 8       identifyCodes: "1234567890",
 9       identifyCode: ""
10     };
11   },
12   methods: {
13    
14     randomNum(min, max) {
15       return Math.floor(Math.random() * (max - min) + min);
16     },
17     refreshCode() {
18       this.identifyCode = "";
19       this.makeCode(this.identifyCodes, 4);
20     },
21     makeCode(o, l) {
22       for (let i = 0; i < l; i++) {
23         this.identifyCode += this.identifyCodes[
24           this.randomNum(0, this.identifyCodes.length)
25         ];
26       }
27       console.log(this.identifyCode);
28     }
29   },
30   mounted() {
31     this.identifyCode = "";
32     this.makeCode(this.identifyCodes, 4);
33   }
34 };

HTML 部分：

1 <div class="coderight" @click="refreshCode">
2                     <SIdentify :identifyCode="identifyCode"></SIdentify>
3                   </div>

效果图：

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原文地址：https://www.cnblogs.com/jervy/p/12917732.html