window.onload = function () {
    var wrapTop = $(".youshi").offset().top;
    var istrue = true;
    $(window).on("scroll",
        function () {
            var s = $(window).scrollTop();
            if (s > wrapTop - 820 && istrue) {
                $(".timer").each(count);
                function count(a) {
                    var b = $(this);
                    a = $.extend({},
                        a || {},
                        b.data("countToOptions") || {});
                    b.countTo(a)
                }

                istrue = false;
            }
        });

    //设置计数
    $.fn.countTo = function (options) {
        options = options || {};
        return $(this).each(function () {
            //当前元素的选项
            var settings = $.extend({}, $.fn.countTo.defaults, {
                from: $(this).data('from'),
                to: $(this).data('to'),
                speed: $(this).data('speed'),
                refreshInterval: $(this).data('refresh-interval'),
                decimals: $(this).data('decimals')
            }, options);
            //更新值
            var loops = Math.ceil(settings.speed / settings.refreshInterval),
                increment = (settings.to - settings.from) / loops;
            //更改应用和变量
            var self = this,
                $self = $(this),
                loopCount = 0,
                value = settings.from,
                data = $self.data('countTo') || {};
            $self.data('countTo', data);
            //如果有间断，找到并清除
            if (data.interval) {
                clearInterval(data.interval);
            }
            ;
            data.interval = setInterval(updateTimer, settings.refreshInterval);
            //初始化起始值
            render(value);
            function updateTimer() {
                value += increment;
                loopCount++;
                render(value);
                if (typeof(settings.onUpdate) == 'function') {
                    settings.onUpdate.call(self, value);
                }
                if (loopCount >= loops) {
                    //移出间隔
                    $self.removeData('countTo');
                    clearInterval(data.interval);
                    value = settings.to;
                    if (typeof(settings.onComplete) == 'function') {
                        settings.onComplete.call(self, value);
                    }
                }
            }

            function render(value) {
                var formattedValue = settings.formatter.call(self, value, settings);
                $self.html(formattedValue);
            }
        });
    };
    $.fn.countTo.defaults = {
        from: 0,               //数字开始的值
        to: 0,                 //数字结束的值
        speed: 1000,           //设置步长的时间
        refreshInterval: 100,  //隔间值
        decimals: 0,           //显示小位数
        formatter: formatter, //渲染之前格式化
        onUpdate: null,        //每次更新前的回调方法
        onComplete: null       //完成更新的回调方法
    };
    function formatter(value, settings) {
        return value.toFixed(settings.decimals);
    }

    //自定义格式
    $('#count-number').data('countToOptions', {
        formmatter: function (value, options) {
            return value.toFixed(options.decimals).replace(/\B(?=(?:\d{3})+(?!\d))/g, ',');
        }
    });

    //定时器
    $('.timer').each(count);
    function count(options) {
        var $this = $(this);
        options = $.extend({}, options || {}, $this.data('countToOptions') || {});
        $this.countTo(options);
    }
};