[英]Detecting if Html element is overlapping another Html element
在jQuery或Javascript中，我如何检测img标签是否与另一个img标签重叠？
你可以通过找到元素的偏移量 ，然后找到每个元素的宽度和高度来做到这一点。 然后，只需要简单的数学来确定它们是否重叠。
我不会为你做所有的工作，但这应该让你走在正确的轨道上：
<div id="one"></div>
<div id="two"></div>
<script>
var offsetOne = $('#one').offset();
var offsetTwo = $('#two').offset();
var widthOne = $('#one').width();
var widthTwo = $('#two').width();
var heightOne = $('#one').height();
var heightTwo = $('#two').height();
</script>
剩下的就是使用两个偏移量的.top＆.left以及宽度和高度来确定是否存在重叠。 查看我的答案第一段中每个功能的文档链接。
我刚写了一个js文件供你使用=）希望它可以帮助你......我花了一段时间才完成它
您可以从以下链接下载： solid-dotheyoverlap.js
只需包含那个js文件并调用doTheyOverlap函数和你想知道它们是否重叠的两个div，就是这样！
这是我为你做的一个基本而简单的例子：
<html>
<head>
<title>Test</title>
<script type="text/javascript" src="jquery-1.7.2.min.js"></script>
<script type="text/javascript" src="solid-dotheyoverlap.js"></script>
<script type="text/javascript">
$(function() {
alert(doTheyOverlap($('#div0'),$('#div1')));
});
</script>
</head>
<body>
<div id="div0" style="position: absolute; width : 200px; height : 200px; background-color : red">div 0</div>
<div id="div1" style="position: absolute; width : 200px; height : 200px; background-color : yellow; top:100px; left:100px">div 1</div>
</body>
</html>
而且我写的solid-doTheyOverlap.js的代码比@artwl提出的解决方案更清晰，更有效。 它是这样的：
function doTheyOverlap(div0, div1){return (yInstersection(div0, div1) && xInstersection(div0, div1));}
function findSmallestY(div0, div1){
return (div0.offset().top < div1.offset().top)? div0 : div1;
}
function yInstersection(div0, div1){
var divY0 = findSmallestY(div0, div1);
var divY1 = (div0 != divY0)? div0 : div1;
return (divY0.offset().top + divY0.height()) - divY1.offset().top > 0;
}
function findSmallestX(div0, div1){
return (div0.offset().left < div1.offset().left)? div0 : div1;
}
function xInstersection(div0, div1){
var divX0 = findSmallestX(div0, div1);
var divX1 = (div0 != divX0)? div0 : div1;
return (divX0.offset().left + divX0.width()) - divX1.offset().left > 0;
}
用简单的话来说，我意识到“弄清楚2个方格是否重叠就像弄清楚它们的分段（根据x轴和y轴）是否过分一样简单”，在javascript中它就像这样“ doTheyOverlap(div0, div1){return (yInstersection(div0, div1) && xInstersection(div0, div1));} “，从那里就像一对减法一样简单（ (divY0.offset().top + divY0.height()) - divY1.offset().top > 0 ， (divX0.offset().left + divX0.width()) - divX1.offset().left > 0 ）以确定这些段是否重叠。
使用getBoundingClientRect（）的另一种方式。 我正在分享这个，因为我不喜欢这里的答案，这是我的解决方案。
function checkForOverlap(el1, el2) {
var bounds1 = el1.getBoundingClientRect();
var bounds2 = el2.getBoundingClientRect();
var firstIstLeftmost = (bounds1.left <= bounds2.left);
var leftest = firstIstLeftmost ? bounds1 : bounds2;
var rightest = firstIstLeftmost ? bounds2 : bounds1;
//change to >= if border overlap should count
if(leftest.right > rightest.left) {
//
var firstIsTopmost = (bounds1.top <= bounds2.top);
var topest = firstIsTopmost ? bounds1 : bounds2;
var bottomest = firstIsTopmost ? bounds2 : bounds1;
//change to >= if border overlap should count
return topest.bottom > bottomest.top;
}
else return false;
}
<style type="text/css">
div{
width:200px;
height:200px;
background:#EEE;
}
#two{
position:absolute;
left:100px;
top:50px;
background:#F60;
}
</style>
<div id="one">One</div>
<div id="two">Two</div>
<div id="three">Three</div>
<script>
console.log(isOverlap("one","two"));//true
console.log(isOverlap("one","three"));//false
console.log(isOverlap("two","three"));//true
function isOverlap(idOne,idTwo){
var objOne=$("#"+idOne),
objTwo=$("#"+idTwo),
offsetOne = objOne.offset(),
offsetTwo = objTwo.offset(),
topOne=offsetOne.top,
topTwo=offsetTwo.top,
leftOne=offsetOne.left,
leftTwo=offsetTwo.left,
widthOne = objOne.width(),
widthTwo = objTwo.width(),
heightOne = objOne.height(),
heightTwo = objTwo.height();
var leftTop = leftTwo > leftOne && leftTwo < leftOne+widthOne
&& topTwo > topOne && topTwo < topOne+heightOne,
rightTop = leftTwo+widthTwo > leftOne && leftTwo+widthTwo < leftOne+widthOne
&& topTwo > topOne && topTwo < topOne+heightOne,
leftBottom = leftTwo > leftOne && leftTwo < leftOne+widthOne
&& topTwo+heightTwo > topOne && topTwo+heightTwo < topOne+heightOne,
rightBottom = leftTwo+widthTwo > leftOne && leftTwo+widthTwo < leftOne+widthOne
&& topTwo+heightTwo > topOne && topTwo+heightTwo < topOne+heightOne;
return leftTop || rightTop || leftBottom || rightBottom;
}
</script>
@solid snake，我把你的代码改写成一个更简洁的形式：
function doTheyOverlap(el0, el1)
{
var elY0 = (el0.offsetTop < el1.offsetTop)? el0 : el1;
var elY1 = (el0 != elY0)? el0 : el1;
var yInstersection = (elY0.offsetTop + elY0.clientHeight) - elY1.offsetTop > 0;
var elX0 = (el0.offsetLeft < el1.offsetLeft)? el0 : el1;
var elX1 = (el0 != elX0)? el0 : el1;
var xInstersection = (elX0.offsetLeft + elX0.clientWidth) - elX1.offsetLeft > 0;
return (yInstersection && xInstersection);
}
尽管从2012年开始，这个答案仍然具有相关性
编辑：更新的代码
使用jQuery检测在另一个HTML元素上移动的HTML元素
[英]Detecting a html element moving over another html element using jquery
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