canvas随机验证码

Html

Css

$(function() {
    var show_num = [];
    draw(show_num);
    $("#canvas").on('click', function() {
        draw(show_num);
    })
    $(".btn").on('click', function() {
        var val = $(".input-val").val().toLowerCase();
        var num = show_num.join("");
        if (val == '') {
            alert('请输入验证码！');
        } else if (val == num) {
            alert('提交成功！');
            $(".input-val").val('');
            draw(show_num);

} else {
            alert('验证码错误！请重新输入！');
            $(".input-val").val('');
            draw(show_num);
        }
    })
})

function draw(show_num) {
    var canvas_width = $('#canvas').width();
    var canvas_height = $('#canvas').height();
    var canvas = document.getElementById("canvas"); //获取到canvas的对象，演员 
    var 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;
    var 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";
    var aCode = sCode.split(",");
    context.font = "bold 53px 微软雅黑";
    var aLength = aCode.length; //获取到数组的长度        
    for (var i = 0; i <= 3; i++) {
        var j = Math.floor(Math.random() * aLength); //获取到随机的索引值 
        var deg = Math.random() * 30 * Math.PI / 180; //产生0~30之间的随机弧度 
        var txt = aCode[j]; //得到随机的一个内容 
        show_num[i] = txt.toLowerCase();
        var x = 10 + i * 20; //文字在canvas上的x坐标 
        var 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 = 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 = 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 = 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();
    }
}

function randomColor() { //得到随机的颜色值 
    var r = Math.floor(Math.random() * 256);
    var g = Math.floor(Math.random() * 256);
    var b = Math.floor(Math.random() * 256);
    return "rgb(" + r + "," + g + "," + b + ")";
}

↑上面代码改变，会自动显示代码结果 jQuery调用版本：1.11.3

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canvas随机验证码



代码描述：jQuery canvas实现随机验证码

更新时间：2021-07-16 00:21:41

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