1、作用于自身
.oneself:hover {
color: #0000ff;
}
<div class='oneself'>作用于自身</div>
2、作用于子元素
.child_element_box:hover>.child_element {
color: #0000ff;
}
<div class="child_element_box">
<div class="child_element">作用于子元素</div>
</div>
3、作用于兄弟元素
选择下一个紧挨的兄弟元素
.be_next_to_closely:hover+div {
color: #0000ff;
}
<div>
<div class="be_next_to_closely">选择紧挨的兄弟元素</div>
<div>紧挨着的元素</div>
<div>不是紧挨着的元素</div>
</div>
选择后边所有符合条件的兄弟元素
.all_element:hover~.elements {
color: #0000ff;
}
<div>
<div class="all_element">选择后边所有符合条件的兄弟元素</div>
<div class="elements">符合的元素1</div>
<div>不符合的元素1</div>
<div class="elements">符合的元素2</div>
</div>
4、使用JavaScript配合CSS实现样式修改
.box {
width: 100%;
height: calc(100vh - 17px);
background-image: url('./img/by01.jpg');
}
.tab_bar_box {
position: fixed;
left: 50%;
top: 50%;
transform: translate(-50%, -50%);
}
.tab_bar_box>span {
display: inline-block;
width: 130px;
border: 1px solid #777777;
border-radius: 7px;
padding: 7px;
margin: 0;
text-align: center;
cursor: pointer;
background-color: #eeeeee;
opacity: .3;
}
.tab_bar_box>span:nth-child(2) {
margin: 0 68px;
}
.tab_bar_1:hover,
.tab_bar_2:hover,
.tab_bar_3:hover {
color: #0000ff;
font-weight: 700;
border: 1px solid #0000ff;
opacity: .7;
}
<div class="box">
<div class="tab_bar_box">
<span class="tab_bar_1">标签1</span>
<span class="tab_bar_2">标签2</span>
<span class="tab_bar_3">标签3</span>
</div>
</div>
(function () {
let tabBar1 = document.querySelector('.tab_bar_1'),
tabBar2 = document.querySelector('.tab_bar_2'),
tabBar3 = document.querySelector('.tab_bar_3'),
box = document.querySelector('.box');
tabBar1.addEventListener("mouseenter", mouseenter, false);
tabBar1.addEventListener("mouseleave", mouseleave, false);
tabBar2.addEventListener("mouseenter", mouseenter, false);
tabBar2.addEventListener("mouseleave", mouseleave, false);
tabBar3.addEventListener("mouseenter", mouseenter, false);
tabBar3.addEventListener("mouseleave", mouseleave, false);
function mouseenter(e) {
let indexArr = e.target.className.split('_'),
i = indexArr[indexArr.length - 1],
arr = ["url('./img/by07.jpg')", "url('./img/by09.jpg')", "url('./img/by12.jpg')"];
box.style.backgroundImage = arr[i - 1];
box.style.transitionDuration = '.7s';
}
function mouseleave() {
box.style.backgroundImage = `url('./img/by01.jpg')`;
box.style.transitionDuration = '.7s';
}
})();
5、鼠标移入移出事件的区别
移入事件
mouseover
:不论鼠标指针穿过被选元素或其子元素,都会触发mouseover事件。对应mouseout
mouseenter
:只有在鼠标指针穿过被选元素时,才会触发mouseenter事件。对应mouseleave
鼠标移出事件
mouseout
:不论鼠标指针离开被选元素还是任何子元素,都会触发mouseout事件
mouseleave
:只有在鼠标指针离开被选元素时,才会触发mouseleave事件