随笔- 354 文章- 0 评论- 3 阅读- 16万

stepValue

<body>
    <style type="text/css">
        * {
            margin: 0;
            padding: 0;
        }

        textarea {
            display: block;
            margin: 50px auto;
            padding-left: 0;
            width: 400px;
            height: 150px;
            ;
            line-height: 30px;
            font-size: 20px;
            font-weight: normal;
            text-align: left;
            border: 1px solid #ccc;
            box-shadow: 0 0 0 7px rgba(255, 255, 255, 0.85), 0 0 7px 7px rgba(0, 0, 0, 0.25), 0 0 40px 2px rgba(0, 0, 0, 0.25) inset;
        }
    </style>
    <textarea>江湖笑恩怨了 人过招笑藏刀 红尘笑笑寂寥 心太高到不了 明月照路迢迢 人会老心不老 爱不到放不掉 忘不了你的好 看似花非花雾非雾 滔滔江水留不住</textarea>
</body>
<script type="text/javascript" src="jquery-3.1.1.min.js"></script>
<script type="text/javascript">
    $.fn.extend({
        stepValue: function (option) {
            var option = $.extend({
                fq: 250
            }, option);
            var that = this,
                index = 0,
                val = that.val().split(""),
                length = val.length;
            that.val("");
            that.focus();
            var timer = setInterval(function () {
                if (index >= length) {
                    clearInterval(timer);
                    return false;
                };
                that.val($("textarea").val() + val[index]);
                index++;
            }, option.fq);
        }
    });
    $("textarea").stepValue({
        fq: 100
    });
</script>