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  • 前端封装验证码方法,封装验证码类

    <!DOCTYPE html>
    <html>
        <head>
            <meta charset="UTF-8">
            <meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate" />
            <meta http-equiv="Pragma" content="no-cache" />
            <meta http-equiv="Expires" content="0" />
            <meta name="viewport" content="width=device-width, initial-scale=1,maximum-scale=1,user-scalable=no">
            <meta name="apple-mobile-web-app-capable" content="yes">
            <meta name="apple-mobile-web-app-status-bar-style" content="black">
            <title>验证码生成示例</title>
            <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/mui/3.7.1/css/mui.css" />
            <style>
                /*验证码*/
                .verificationCode{
                    width: 8rem;
                    height: 100%;
                    position: absolute;
                    right: 0;
                }
                canvas{
                    width: 100%;
                    height: 100%;
                }
                #code_img {
                    width: 100%;
                    height: 100%;
                    cursor: pointer;
                    vertical-align: top;
                }
            </style>
        </head>
        <body>
            <div class="mui-content">
                <div class="mui-input-row login_input">
                    <label>验证码</label>
                    <input type="text" id="verifital_input" class="mui-input" placeholder="请输入验证码">
                    <div id="verificationCode" class="verificationCode">
                        <canvas width="100" height="40" id="verifyCanvas"></canvas>
                        <img id="code_img">
                    </div>
                </div>
            </div>
        </body>
        <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mui/3.7.1/js/mui.min.js" ></script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.slim.js" integrity="sha256-fNXJFIlca05BIO2Y5zh1xrShK3ME+/lYZ0j+ChxX2DA=" crossorigin="anonymous"></script>
        <!-- <script type="text/javascript" src="verificationCode.js" ></script> -->
        <script>
            // 自行封装验证码类
            class drawCanvas {
                constructor() {
                    this.state = {
                        nums: ["1", "2", "3", "4", "5", "6", "7", "8", "9", "0",
                            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
                            'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
                        ],
                    }
                }
    
                // 绘制验证码
                drawCode =  (dom, imgDom) => {
                    let {nums} = this.state;
                    var canvas = dom; //获取HTML端画布
                    var context = canvas.getContext("2d"); //获取画布2D上下文
                    context.fillStyle = "cornflowerblue"; //画布填充色
                    context.fillRect(0, 0, canvas.width, canvas.height); //清空画布
                    context.fillStyle = "white"; //设置字体颜色
                    context.font = "25px Arial"; //设置字体
                    var rand = new Array();
                    var x = new Array();
                    var y = new Array();
                    for (var i = 0; i < 4; i++) {
                        rand.push(rand[i]);
                        rand[i] = nums[Math.floor(Math.random() * nums.length)]
                        x[i] = i * 20 + 10;
                        y[i] = Math.random() * 20 + 20;
                        context.fillText(rand[i], x[i], y[i]);
                    }
                    //画3条随机线
                    for (var i = 0; i < 3; i++) {
                        this.drawline(canvas, context);
                    }
    
                    // 画30个随机点
                    for (var i = 0; i < 30; i++) {
                        this.drawDot(canvas, context);
                    }
                    this.convertCanvasToImage(canvas, dom, imgDom);
                }
    
                // 随机线
                drawline = (canvas, context) => {
                    context.moveTo(Math.floor(Math.random() * canvas.width), Math.floor(Math.random() * canvas.height)); //随机线的起点x坐标是画布x坐标0位置,y坐标是画布高度的随机数
                    context.lineTo(Math.floor(Math.random() * canvas.width), Math.floor(Math.random() * canvas.height)); //随机线的终点x坐标是画布宽度,y坐标是画布高度的随机数
                    context.lineWidth = 0.5; //随机线宽
                    context.strokeStyle = 'rgba(50,50,50,0.3)'; //随机线描边属性
                    context.stroke(); //描边,即起点描到终点
                }
    
                // 随机点(所谓画点其实就是画1px像素的线,方法不再赘述)
                drawDot = (canvas, context) => {
                    var px = Math.floor(Math.random() * canvas.width);
                    var py = Math.floor(Math.random() * canvas.height);
                    context.moveTo(px, py);
                    context.lineTo(px + 1, py + 1);
                    context.lineWidth = 0.2;
                    context.stroke();
    
                }
    
                // 绘制图片
                convertCanvasToImage = (canvas, dom, imgDom) => {
                    dom.style.display = "none";
                    var image = imgDom;
                    image.src = canvas.toDataURL("image/png");
                    return image;
                }
            }
            const canvasItem = new drawCanvas(); // 实例化
            canvasItem.drawCode(document.getElementById("verifyCanvas"), document.getElementById("code_img"));
    
            document.getElementById('code_img').onclick = function() {
                $('#verifyCanvas').remove();
                $('#code_img').before('<canvas width="100" height="40" id="verifyCanvas"></canvas>')
                canvasItem.drawCode(document.getElementById("verifyCanvas"), document.getElementById("code_img"));
            }
            console.log('-----canvans-----')
        </script>
    </html>

    有什么不对的地方还望指教,谢谢您的赞。。。。。

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  • 原文地址:https://www.cnblogs.com/GongYaLei/p/11127463.html
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