如何在滚动期间检查javascript中的div是否在屏幕上

右：Math.min（1，（viewport.right - bounds.left）/ width） }; return（deltas.left * deltas .right）> = x &&（deltas.top * deltas.bottom）> = y; }; 基于上面的代码，我正在查看条件window.onload方法中的页面加载。 过程如下.... （窗口）.scroll（function（） { if（ hello frinds , i have to check that a division is on screen or not . i get a solution when i was googling . but its not working. my code is below , please tell me what i am missing in it . $.fn.isOnScreen = function (x, y) { if (x == null || typeof x == 'undefined') x = 1; if (y == null || typeof y == 'undefined') y = 1; var win = $(window); var viewport = { top: win.scrollTop(), left: win.scrollLeft() }; viewport.right = viewport.left + win.width(); viewport.bottom = viewport.top + win.height(); var height = this.outerHeight(); var width = this.outerWidth(); if (!width || !height) { return false; } var bounds = this.offset(); bounds.right = bounds.left + width; bounds.bottom = bounds.top + height; var visible = (!(viewport.right < bounds.left || viewport.left > bounds.right || viewport.bottom < bounds.top || viewport.top > bounds.bottom)); if (!visible) { return false; } var deltas = { top: Math.min(1, (bounds.bottom - viewport.top) / height), bottom: Math.min(1, (viewport.bottom - bounds.top) / height), left: Math.min(1, (bounds.right - viewport.left) / width), right: Math.min(1, (viewport.right - bounds.left) / width) }; return (deltas.left * deltas.right) >= x && (deltas.top * deltas.bottom)>=y;};based on the above code , i am checking a condition on page load in window.onload method .process is given below....$(window).scroll(function () { if ($('#my_div').isOnScreen(0.5, 0.5) == true) { if (ViewCount != 1) { ViewCount = 1; AdToLoad = 0; alert('Yes'); } } else { if (ViewCount != 1) { ViewCount = 0; AdToLoad = 0; } }});but its not working . its showing error Uncaught TypeError: $(...).isOnScreen is not a function.what i am missing in that . please guide. 解决方案 .fn.isOnScreen = function (x, y) { if (x == null || typeof x == 'undefined') x = 1; if (y == null || typeof y == 'undefined') y = 1; var win =(window); var viewport = { top: win.scrollTop(), left: win.scrollLeft() }; viewport.right = viewport.left + win.width(); viewport.bottom = viewport.top + win.height(); var height = this.outerHeight(); var width = this.outerWidth(); if (!width || !height) { return false; } var bounds = this.offset(); bounds.right = bounds.left + width; bounds.bottom = bounds.top + height; var visible = (!(viewport.right < bounds.left || viewport.left > bounds.right || viewport.bottom < bounds.top || viewport.top > bounds.bottom)); if (!visible) { return false; } var deltas = { top: Math.min(1, (bounds.bottom - viewport.top) / height), bottom: Math.min(1, (viewport.bottom - bounds.top) / height), left: Math.min(1, (bounds.right - viewport.left) / width), right: Math.min(1, (viewport.right - bounds.left) / width) }; return (deltas.left * deltas.right) >= x && (deltas.top * deltas.bottom)>=y;};based on the above code , i am checking a condition on page load in window.onload method .process is given below....(window).scroll(function () { if ( 这篇关于如何在滚动期间检查javascript中的div是否在屏幕上的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！