技術標籤：JavaScriptjscanvasvue.js

<template>
    <div>
        <canvas id="canvas" width="100" height="34" @click="changeCode" style="border: 1px solid #ccc;border-radius: 5px;"></canvas>
    </div>
</template>

<script>
    export default {
        name: "Test5",
        methods:{
            changeCode(){
                let show_num = [];
                let canvas_width=document.getElementById('canvas').clientWidth;
                let canvas_height=document.getElementById('canvas').clientHeight;
                let canvas = document.getElementById("canvas");//獲取到canvas的物件，演員
                let context = canvas.getContext("2d");//獲取到canvas畫圖的環境，演員表演的舞臺
                canvas.width = canvas_width;
                canvas.height = canvas_height;
                let sCode = "A,B,C,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,W,X,Y,Z,1,2,3,4,5,6,7,8,9,0,q,w,e,r,t,y,u,i,o,p,a,s,d,f,g,h,j,k,l,z,x,c,v,b,n,m";
                let aCode = sCode.split(",");
                let aLength = aCode.length;//獲取到陣列的長度

                for (let i = 0; i <= 3; i++) {
                    let j = Math.floor(Math.random() * aLength);//獲取到隨機的索引值
                    let deg = Math.random() * 30 * Math.PI / 180;//產生0~30之間的隨機弧度
                    let txt = aCode[j];//得到隨機的一個內容
                    show_num[i] = txt;
                    let x = 10 + i * 20;//文字在canvas上的x座標
                    let y = 20 + Math.random() * 8;//文字在canvas上的y座標
                    context.font = "bold 23px 微軟雅黑";

                    context.translate(x, y);
                    context.rotate(deg);

                    context.fillStyle = this.randomColor();
                    context.fillText(txt, 0, 0);

                    context.rotate(-deg);
                    context.translate(-x, -y);
                }
                for (let i = 0; i <= 5; i++) { //驗證碼上顯示線條
                    context.strokeStyle = this.randomColor();
                    context.beginPath();
                    context.moveTo(Math.random() * canvas_width, Math.random() * canvas_height);
                    context.lineTo(Math.random() * canvas_width, Math.random() * canvas_height);
                    context.stroke();
                }
                for (let i = 0; i <= 30; i++) { //驗證碼上顯示小點
                    context.strokeStyle = this.randomColor();
                    context.beginPath();
                    let x = Math.random() * canvas_width;
                    let y = Math.random() * canvas_height;
                    context.moveTo(x, y);
                    context.lineTo(x + 1, y + 1);
                    context.stroke();
                }
                this.captchaCode = '';
                for (let i in show_num){
                    this.captchaCode = this.captchaCode + show_num[i];
                }
            },
            randomColor() {//得到隨機的顏色值
                let r = Math.floor(Math.random() * 256);
                let g = Math.floor(Math.random() * 256);
                let b = Math.floor(Math.random() * 256);
                return "rgb(" + r + "," + g + "," + b + ")";
            }
        },
        mounted(){
            this.changeCode();
        }
    }
</script>

<style scoped>

</style>
 

效果圖