条件匹配后仅运行jQuery事件一次 [英] Run jQuery event only once after a condition matches

问题描述

我正在制作在线产品网站，我触发了一个滚动事件，在启动时只会显示12个元素，但当第8个元素滚动到顶部滚动事件时，应该只运行一次，但每次向下滚动时都会运行， 请帮忙。
这里是我的代码：

I am making online product site, I am trigging a scroll event, at starting only 12 elements will be shown but when 8th element is scrolled to top scroll event should run only once, but it is running every time when I scroll down, please help. Here is my Code:

var navigation_offset_top = $('.prods-list li:nth-child(4)').offset().top;  
    $(window).on("scroll",function(){
        var scroll_top = $(window).scrollTop(); // current vertical position from the top
        // if scrolled more than the navigation, change its position to fixed to stick to top, otherwise change it back to relative
        if (scroll_top > sticky_navigation_offset_top) 
        { 
            console.log("Hi");
        }       
    });

推荐答案

我认为您需要的是 .one 方法

$(window).one("scroll",function(){
    var scroll_top = $(window).scrollTop(); // current vertical position from the top
    // if scrolled more than the navigation, change its position to fixed to stick to top, otherwise change it back to relative
    if (scroll_top > sticky_navigation_offset_top) 
    { 
        console.log("Hi");
    }       
});

您可以在这里了解更多信息： http://api.jquery.com/one/

You can learn more here: http://api.jquery.com/one/

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