js生成图片验证码
页面代码：（使用到了mui样式）
<!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="../css/mui/mui.min.css" /> <style> /*验证码*/ .verificationCode{ width: 4rem; 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="../js/mui/mui.js" ></script> <script type="text/javascript" src="../js/jquery-3.3.1.min.js" ></script> <script type="text/javascript" src="verificationCode.js" ></script> <script> console.log(verVal) </script> </html>
verificationCode.js代码：
var 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' ]; var str = ''; var verVal = drawCode(); // 绘制验证码 function drawCode (str) { var canvas = document.getElementById("verifyCanvas"); //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]); } str = rand.join('').toUpperCase(); //画3条随机线 for (var i = 0; i < 3; i++) { drawline(canvas, context); } // 画30个随机点 for (var i = 0; i < 30; i++) { drawDot(canvas, context); } convertCanvasToImage(canvas); return str; } // 随机线 function 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) function 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 function convertCanvasToImage (canvas) { document.getElementById("verifyCanvas").style.display = "none"; var image = document.getElementById("code_img"); image.src = canvas.toDataURL("image/png"); return image; } // 点击图片刷新 document.getElementById('code_img').onclick = function() { resetCode(); } function resetCode () { $('#verifyCanvas').remove(); $('#code_img').before('<canvas width="100" height="40" id="verifyCanvas"></canvas>') verVal = drawCode(); }
