前端实现6位验证码输入框效果

这个验证码输入应用场景非常的多，看起来很简单的，但是做起来还是有一些坑。

首先的想法就是6个input框，每输入一个数字之后，切换到下一个input，即切换focus，如果输入很快的话，会导致切换不过来
有卡顿的感觉，pass掉，所以最后使用一个input来接受输入最好，通过样式来切割成6个框，感觉这种也不好控制也就pass掉；

最后的想法是放6个input框，但是全都是disabled的，然后让一个隐藏的input来接受输入，这个input添加change事件，让接受到的值分割后在赋到其他6个disabled框中显示出来。

先看看效果：

效果图

Html code如下：

<div class="page-container">
    <div class="main-contant">
        <div class="pd-container con-message text-center">
            <p class="ff-seravek-light">Enter the One-Time Password sent to your mobile number:
                <span class="ff-seravek">1502****760</span>
            </p>
        </div>
        <div class="pd-container">
            <form role="form" action="/auth/login/otp" method="post">
                <div class="checked-codes">
                    <p>One-Time Password</p>
                    <div class="flex code-container" onclick="focusHandler()">
                        <input disabled="disabled" class="tb-code" type="number" id="tb0" />
                        <input disabled="disabled" class="tb-code" type="number" id="tb1" />
                        <input disabled="disabled" class="tb-code" type="number" id="tb2" />
                        <input disabled="disabled" class="tb-code" type="number" id="tb3" />
                        <input disabled="disabled" class="tb-code" type="number" id="tb4" />
                        <input disabled="disabled" class="tb-code" type="number" id="tb5" />
                        </div>
                    </div>
                    <input id="hdcode" type="number" name="otp" style="opacity: 0;" onkeydown="inputNumOnly(this)" onkeyup="keyupHandler(this)"/>
                    <div class="pd-container text-center">
                        <button id="btn-submit-form" type="submit" style="display: none">Next</button>
                    </div>
            </form>
        </div>
    </div>
</div>

js code：

<script>
    function inputNumOnly(e) {
        if (!(event.keyCode == 46) && !(event.keyCode == 8) && !(event.keyCode == 37) && !(event.keyCode == 39)) {
            if (!((event.keyCode >= 48 && event.keyCode <= 57) || (event.keyCode >= 96 && event.keyCode <= 105))) {
                event.returnValue = false;
            }
            if (e.value && e.value.length >= 6) {
                event.returnValue = false;
            }
        }
    }
    function keyupHandler(e) {
        e.value = e.value.substr(0, 6);
        code = e.value
        for (var i = 0; i < 6; i++) {
            if (i < code.length) {
                document.getElementById("tb" + i).value = code[i];
            } else {
                document.getElementById("tb" + i).value = "";
            }
        }
        if (code.length === 6) {
            document.getElementById("btn-submit-form").style.display = "block";
        }
    }
    function focusHandler(e) {
        document.getElementById("hdcode").focus();
    }
</script>

css code 只截取了部分:

    <style type="text/css">
        /* page-container */
        .page-container {
            position: absolute;
            bottom: 0;
            top: 0;
            left: 50%;
            margin-left: -150px;
            font-family: "Seravek Light";
            font-size: 16px;
            font-weight: normal;
            line-height: 1.4;
            color: #eee;
            overflow: auto;
            border-radius: 3px;
            padding: 50px 0;
            height: auto;
            width: 100%;
            max-width: 300px;
            overflow-y: hidden;
            background: linear-gradient(#00815a, #008120);
            box-shadow: 0 2px 0 rgba(175, 175, 175, 0.12);
        }

        .pd-container {
            padding: 10px 30px;
        }

        .bg-green-lighter {
            background: linear-gradient(#339a7b, #339a3d);
        }

        @media only screen and (max-width: 600px) {
            .page-container {
                position: absolute;
                bottom: 0;
                top: 0;
                left: 0;
                margin: 0;
                padding: 20px 0;
                border: none;
                box-shadow: none;
                width: 100%;
                max-width: 100%;
            }
        }

        @media only screen and (min-height: 736px) {
            .page-container {
                padding: 120px 0;
            }
        }

        /* checked-codes */
        .checked-codes {
            max-width: 300px;
            margin: 0 auto;
        }

        .checked-codes .flex {
            justify-content: space-between;
        }

        .checked-codes a {
            float: right;
            font-size: 13px;
            color: #000000;
            text-decoration: underline;
            line-height: 13px
        }

        .checked-codes input {
            box-sizing: border-box;
            height: 40px;
            max-width: 40px;
            border: solid 1px #eee;
            border-radius: 4px;
            margin: 0 2px;
            flex: 1;
            font-size: 18px;
            text-align: center;
            background-color: transparent;
            color: #eee;
        }


        .con-message {
            padding-top: 100px;
            padding-bottom: 50px;
        }

        button {
            padding: 6px 0;
            margin: 10px 0;
        }

        .code-tip {
            font-size: 14px;
        }

        .code-container:active {
            -moz-box-shadow: 0px 7px 20px #333333;
            -webkit-box-shadow: 0px 7px 20px #333333;
            box-shadow: 0px 7px 20px #333333;
        }

        .flex {
            display: flex;
        }
    </style>

END!!!