vue.js+canvas实现随机验证码

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<template>
  <div class="about">
    <p>当前验证码：{{codeStr}}</p>
    <canvas id="canvas" width="100" height="43" @click="createCode"></canvas>
  </div>
</template>
<script>

export default {
    data(){
      return{
        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",
        codeStr:[], //当前code码
      }
    },
    mounted:function(){
      this.createCode()
    },
    methods:{
        //得到随机的颜色值
        randomColor() {
            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 + ")";
        },
        // 生成二维码
        createCode(){
            this.codeStr = ''
            let canvas_width=document.getElementById('canvas').clientWidth;
            let canvas_height=document.getElementById('canvas').clientHeight;
            let canvas = document.getElementById("canvas");//获取到canvas的对象，演员
            let context = canvas.getContext("2d");//获取到canvas画图的环境，演员表演的舞台
            canvas.width = canvas_width;
            canvas.height = canvas_height;
            
            let aCode = this.sCode.split(",");
            let aLength = aCode.length;//获取到数组的长度
                
            for (let i = 0; i <= 3; i++) {
                let j = Math.floor(Math.random() * aLength);//获取到随机的索引值
                let deg = Math.random() * 30 * Math.PI / 180;//产生0~30之间的随机弧度
                let txt = aCode[j];//得到随机的一个内容
                this.codeStr+= txt;
                let x = 10 + i * 20;//文字在canvas上的x坐标
                let y = 20 + Math.random() * 8;//文字在canvas上的y坐标
                context.font = "bold 23px 微软雅黑";

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

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

                context.rotate(-deg);
                context.translate(-x, -y);
            }
            for (var i = 0; i <= 5; i++) { //验证码上显示线条
                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 (var i = 0; i <= 30; i++) { //验证码上显示小点
                context.strokeStyle = this.randomColor();
                context.beginPath();
                var x = Math.random() * canvas_width;
                var y = Math.random() * canvas_height;
                context.moveTo(x, y);
                context.lineTo(x + 1, y + 1);
                context.stroke();
            }
        }
    }
}
</script>
<style scoped>
#canvas{
  border: 1px solid #aba5a5;
}
</style>