javascript - 鼠标悬停在图像的特定部分时图像发生变化

Question

<img src="C:/Users/ma/Desktop/start_new_coin/rebulid from  scratch/chaptermap/ch01ch01.png"width="453" height="453" alt="Planets" usemap="#planetmap">
<map name="planetmap">
<area shape="poly" coords="172,227,181,224,183,213,189,201,195,193,199,190,199,184,126,93,135,93,123,79,103,96,84,117,68,140,58,162,51,186,48,201,47,214,135,219,130,227,148,227,147,225,151,227,149,223,153,227,153,221,156,225,157,214,160,202,166,190,174,179,176,177,174,174,191,176,192,192,189,189,180,200,174,212,172,224,172,227" alt="Sun" onmouseover="this.src='C:/Users/ma/Desktop/start_new_coin/rebulid from scratch/chaptermap/ch01ch12.png'" width="453" height="453" onmouseout="this.src='C:/Users/ma/Desktop/start_new_coin/rebulid from scratch/chaptermap/ch01ch01.png'" width="453" height="453"/>
</map>

当鼠标悬停在图像的特定区域时，我正在尝试更改图像。但它并没有改变。这是我的代码。我试过这个，但它在图像悬停时没有改变。

Answer 1

您正在使用 this 引用图像，但是 this实际上是指触发鼠标事件的元素，即<area>。 ;一个<area>标签没有 src您可以使用 javascript 设置的属性。

您需要以不同方式引用图像，例如使用类或 ID:

<img src="image1.png" id="image1" width="453" height="453" alt="Planets" usemap="#planetmap">
<map name="planetmap">
    <area shape="poly" coords="..." alt="Sun"
         onmouseover="document.getElementById('image1').src='image2.png'" 
         onmouseout="document.getElementById('image1').src='image1.png'"/>
</map>

(同时放弃 width 和 height 标签上的 <area> 属性)