onmouseleave - 将背景图像恢复为默认值 [英] onmouseleave --returning background image to default

问题描述

我想使用onmouseleave方法返回一个div的背景图像恢复到默认值。这里是HTML和JS：

I'm trying to return a div's background image back to its default using a onmouseleave method. Here is the HTML and JS:

  <script type="text/javascript">

function displayImage(event) {
event = event || window.event;
var targetElement = event.target || event.srcElement;

 if (targetElement.tagName == "IMG") {
    console.log(document.getElementById("viewer"));
    document.getElementById("viewer").style.backgroundImage = 'url(' + targetElement.getAttribute("src") + ')';}
    }

function leaveImage(event){
  event = event || window.event;
  var targetElement = event.target || event.srcElement;

  if (targetElement.tagName != "IMG") {
    document.getElementById("viewer").style.backgroundImage: URL();
  }

}

其中displayImage和leaveImage使用同一个HTML div标签中的方法调用：

where displayImage and leaveImage are called with the methods in the same HTML div tag:

<div class="thumbnails" onmouseover="displayImage(event)">

本质上，我想将viewerid'd div元素的背景图像返回到默认on mouseleave（创建两个单独的函数）。我要以正确的方式去吗？

In essence, I want to return the "viewer" id'd div element's background image to its default on mouseleave (creating two separate functions). Am I going about it the right way?

谢谢大家！

推荐答案

好吧，它显示[对象HTML集合]，因为你正在调用getElementsByTagName，注意它说元素 ，所以你得到的每一个p标签在你的网站上，你想要的是只是一个单一的。解决方案可能是给p标签一个ID，然后使用getElementById，那么你只会得到单个元素。

Alright, firstly; it's showing [Object HTML Collection] because you are calling getElementsByTagName, Notice it says Elements, so you are getting every single p tag on your website, what you want instead is to get just a single one. The solution could be giving the p tag an ID and then use getElementById, then you would only get the single element.

其次，你需要保存原始的p标签文本这里是一个将其保存在变量中的示例：

Second, you need to save the original p tag text somewhere, here is an example saving it in a variable:

HTML：

<p id="tip">Hover over the image to display larger</p>

Javascript：

Javascript:

var originalText; // Notice this is outside the functions
function displayImage(event) {
    event = event || window.event;  
    var targetElement = event.target || event.srcElement;

    originalText = document.getElementById("tip").innerHTML;
    var altText=targetElement.getAttribute("alt");
    document.getElementById("viewer").innerHTML = altText;


     if (targetElement.tagName == "IMG") {
        console.log(document.getElementById("viewer"));
        document.getElementById("viewer").style.backgroundImage = 'url(' + targetElement.getAttribute("src") + ')';
    }
}

function leaveImage(event){
    event = event || window.event;
    var targetElement = event.target || event.srcElement;

    document.getElementById("viewer").innerHTML = originalText; 

    if (targetElement.tagName != "IMG") {
        document.getElementById("viewer").style.backgroundImage= URL();
      }
 }

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