实例：黑色的简约下拉菜单
技术栈：HTML+CSS+JS
效果：
源码：
【html】
黑色的简约下拉菜单
【css】
*{
/* 初始化 */
margin: 0;
padding: 0;
box-sizing: border-box;
}
/* :root选择器匹配文档根元素 */
:root{
/* 声明自定义属性 */
--rotate-arrow:0;
--dropdown-height:0;
--list-opacity:0;
--translate-value:0;
--floating-icon-size:26;
--floating-icon-top: 0;
--floating-icon-left: 0;
}
html{
font-size: 80%;
}
body{
height: 100%;
/* 弹性布局 水平+垂直居中 */
display: flex;
flex-direction: column;
justify-content: center;
align-items: center;
background-color: #222429;
padding: 1.5rem;
line-height: 1.4rem;
}
button{
border: none;
cursor: pointer;
background-color: transparent;
outline: none;
}
svg{
width: 1.6rem;
height: 1.6rem;
}
.text-truncate{
/* 超出显示省略号 */
text-overflow: ellipsis;
overflow: hidden;
/* 不换行 */
white-space: nowrap;
}
.dropdown-container{
margin-top: 30vh;
display: flex;
flex-direction: column;
width: 100%;
max-width: 34rem;
}
.dropdown-title-icon,
.dropdown-arrow{
display: inline-flex;
}
.dropdown-title{
margin: 0 auto 0 1.8rem;
/* text-transform: capitalize; */
}
.dropdown-button{
font-weight: 400;
font-size: 1.7rem;
display: flex;
align-items: center;
padding: 0 1.8rem;
}
.dropdown-button svg{
/* 设置过渡：全部 时长 贝塞尔曲线 */
transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
/* 填充颜色 */
fill: #b1b8ca;
}
.dropdown-button svg,
.dropdown-button span{
/* 元素不对指针事件做出反应 */
pointer-events: none;
}
.dropdown-button:hover,
.dropdown-button:focus{
color: #fff;
}
.dropdown-button:hover svg,
.dropdown-button:focus svg{
fill: #fff;
}
.main-button{
height: 5.2rem;
background-color: #333740;
color: #b1b8ca;
border-radius: 1.4rem;
border: 0.1rem solid #494d59;
transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}
.main-button:focus{
border: 0.1rem solid #2c62f6;
box-shadow: 0 0 0 0.2rem rgba(44,98,246,0.4);
}
.main-button .dropdown-arrow{
margin-left: 1.8rem;
/* 通过var函数调用自定义属性，设置旋转角度 */
transform: rotate(var(--rotate-arrow));
transition: transform 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}
.list-button{
height: 4.6rem;
color: #b1b8ca;
overflow: hidden;
/* 隐藏光标 */
cursor: none;
transition: color 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}
.dropdown-list-container{
overflow: hidden;
max-height: var(--dropdown-height);
transition: max-height 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}
.dropdown-list-wrapper{
margin-top: 1rem;
padding: 1rem;
background-color: #333740;
border-radius: 1.4rem;
border: 0.1rem solid #494d59;
position: relative;
}
ul.dropdown-list{
position: relative;
list-style-type: none;
}
ul.dropdown-list::before{
content: "";
position: absolute;
top: 0;
right: 0;
left: 0;
z-index: 0;
opacity: 0;
height: 4.6rem;
background-color: #2b2e34;
border-radius: 1.4rem;
pointer-events: none;
transform: translateY(var(--translate-value));
transition: all 0.4s linear;
}
ul.dropdown-list:hover::before,
ul.dropdown-list:hover ~ .floating-icon{
opacity: 1;
}
li.dropdown-list-item{
display: flex;
flex-direction: column;
position: relative;
z-index: 1;
opacity: var(--list-opacity);
transition: opacity 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}
.floating-icon{
width: calc(var(--floating-icon-size) * 1px);
height: calc(var(--floating-icon-size) * 1px);
position: absolute;
left: var(--floating-icon-left);
top: var(--floating-icon-top);
background-color: #494d59;
border-radius: 1rem;
pointer-events: none;
opacity: 0;
z-index: 2;
display: inline-flex;
justify-content: center;
align-items: center;
transition: opacity 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}
.floating-icon svg{
fill: #fff;
}
【js】
// 需要操作到的元素
const root=document.documentElement;
const dropdown_title_icon=document.querySelector(".dropdown-title-icon");
const dropdown_title=document.querySelector(".dropdown-title");
const dropdown_list=document.querySelector(".dropdown-list");
const main_button=document.querySelector(".main-button");
const floating_icon=document.querySelector(".floating-icon");
// 图标对象
const icons = {
"百度":
"M226.8 535.7c96.8-20.8 83.6-136.4 80.6-161.7-4.8-39-50.6-107.2-112.8-101.8-78.3 7-89.8 120.2-89.8 120.2-10.5 52.3 25.4 164.1 122 143.3z m102.7 201.1c-2.9 8.2-9.1 28.9-3.7 47 10.8 40.6 46.1 42.4 46.1 42.4h50.7V702.4h-54.2c-24.5 7.3-36.3 26.3-38.9 34.4z m76.8-395c53.5 0 96.6-61.5 96.6-137.6 0-76-43.1-137.5-96.6-137.5-53.4 0-96.6 61.5-96.6 137.5 0 76.1 43.2 137.6 96.6 137.6z m230.2 9.1c71.4 9.3 117.4-67 126.4-124.8 9.3-57.6-36.8-124.7-87.3-136.2-50.7-11.6-113.9 69.5-119.7 122.4-6.8 64.8 9.3 129.4 80.6 138.6z m175 339.6S701 605 636.5 512.6c-87.4-136.3-211.7-80.8-253.2-11.6-41.4 69.3-105.8 113.1-115 124.7-9.3 11.5-133.5 78.5-105.9 200.9C189.9 949 286.8 946.8 286.8 946.8s71.3 7 154.2-11.5c82.8-18.4 154.1 4.6 154.1 4.6s193.4 64.7 246.4-60c52.8-124.8-30-189.4-30-189.4z m-331 185.6H354.8c-54.3-10.9-76-47.9-78.7-54.2-2.7-6.4-18.1-36.2-9.9-86.9 23.5-76 90.4-81.4 90.4-81.4h66.9v-82.3l57 0.9v303.9z m234.3-0.9H570c-56.1-14.4-58.7-54.3-58.7-54.3v-160l58.7-1v143.8c3.6 15.3 22.7 18.2 22.7 18.2h59.6v-161h62.5v214.3z m204.8-427.3c0-27.6-22.9-110.9-108.1-110.9-85.3 0-96.7 78.6-96.7 134.1 0 53 4.5 127.1 110.5 124.6 106-2.3 94.3-120 94.3-147.8z m0 0",
"微信":
"M693.12 347.264c11.776 0 23.36 0.896 35.008 2.176-31.36-146.048-187.456-254.528-365.696-254.528C163.2 94.912 0 230.656 0 403.136c0 99.52 54.272 181.248 145.024 244.736L108.8 756.864l126.72-63.488c45.312 8.896 81.664 18.112 126.912 18.112 11.392 0 22.656-0.512 33.792-1.344-7.04-24.256-11.2-49.6-11.2-76.032C385.088 475.776 521.024 347.264 693.12 347.264zM498.304 249.024c27.392 0 45.376 17.984 45.376 45.248 0 27.136-17.984 45.312-45.376 45.312-27.072 0-54.336-18.176-54.336-45.312C443.968 266.944 471.168 249.024 498.304 249.024zM244.672 339.584c-27.2 0-54.592-18.176-54.592-45.312 0-27.264 27.392-45.248 54.592-45.248S289.92 266.944 289.92 294.272C289.92 321.408 271.872 339.584 244.672 339.584zM1024 629.76c0-144.896-145.024-262.976-307.904-262.976-172.48 0-308.224 118.144-308.224 262.976 0 145.28 135.808 262.976 308.224 262.976 36.096 0 72.512-9.024 108.736-18.112l99.392 54.528-27.264-90.624C969.728 783.872 1024 711.488 1024 629.76zM616.128 584.384c-17.984 0-36.224-17.92-36.224-36.224 0-18.048 18.24-36.224 36.224-36.224 27.52 0 45.376 18.176 45.376 36.224C661.504 566.464 643.648 584.384 616.128 584.384zM815.488 584.384c-17.856 0-36.032-17.92-36.032-36.224 0-18.048 18.112-36.224 36.032-36.224 27.264 0 45.376 18.176 45.376 36.224C860.864 566.464 842.752 584.384 815.488 584.384z",
"抖音":
"M937.4 423.9c-84 0-165.7-27.3-232.9-77.8v352.3c0 179.9-138.6 325.6-309.6 325.6S85.3 878.3 85.3 698.4c0-179.9 138.6-325.6 309.6-325.6 17.1 0 33.7 1.5 49.9 4.3v186.6c-15.5-6.1-32-9.2-48.6-9.2-76.3 0-138.2 65-138.2 145.3 0 80.2 61.9 145.3 138.2 145.3 76.2 0 138.1-65.1 138.1-145.3V0H707c0 134.5 103.7 243.5 231.6 243.5v180.3l-1.2 0.1",
"哔哩哔哩":
"M306.005333 117.632L444.330667 256h135.296l138.368-138.325333a42.666667 42.666667 0 0 1 60.373333 60.373333L700.330667 256H789.333333A149.333333 149.333333 0 0 1 938.666667 405.333333v341.333334a149.333333 149.333333 0 0 1-149.333334 149.333333h-554.666666A149.333333 149.333333 0 0 1 85.333333 746.666667v-341.333334A149.333333 149.333333 0 0 1 234.666667 256h88.96L245.632 177.962667a42.666667 42.666667 0 0 1 60.373333-60.373334zM789.333333 341.333333h-554.666666a64 64 0 0 0-63.701334 57.856L170.666667 405.333333v341.333334a64 64 0 0 0 57.856 63.701333L234.666667 810.666667h554.666666a64 64 0 0 0 63.701334-57.856L853.333333 746.666667v-341.333334A64 64 0 0 0 789.333333 341.333333zM341.333333 469.333333a42.666667 42.666667 0 0 1 42.666667 42.666667v85.333333a42.666667 42.666667 0 0 1-85.333333 0v-85.333333a42.666667 42.666667 0 0 1 42.666666-42.666667z m341.333334 0a42.666667 42.666667 0 0 1 42.666666 42.666667v85.333333a42.666667 42.666667 0 0 1-85.333333 0v-85.333333a42.666667 42.666667 0 0 1 42.666667-42.666667z",
"淘宝":
"M168.5 273.7a68.7 68.7 0 1 0 137.4 0 68.7 68.7 0 1 0-137.4 0z m730 79.2s-23.7-184.4-426.9-70.1c17.3-30 25.6-49.5 25.6-49.5L396.4 205s-40.6 132.6-113 194.4c0 0 70.1 40.6 69.4 39.4 20.1-20.1 38.2-40.6 53.7-60.4 16.1-7 31.5-13.6 46.7-19.8-18.6 33.5-48.7 83.8-78.8 115.6l42.4 37s28.8-27.7 60.4-61.2h36v61.8H372.9v49.5h140.3v118.5c-1.7 0-3.6 0-5.4-0.2-15.4-0.7-39.5-3.3-49-18.2-11.5-18.1-3-51.5-2.4-71.9h-97l-3.4 1.8s-35.5 159.1 102.3 155.5c129.1 3.6 203-36 238.6-63.1l14.2 52.6 79.6-33.2-53.9-131.9-64.6 20.1 12.1 45.2c-16.6 12.4-35.6 21.7-56.2 28.4V561.3h137.1v-49.5H628.1V450h137.6v-49.5H521.3c17.6-21.4 31.5-41.1 35-53.6l-42.5-11.6c182.8-65.5 284.5-54.2 283.6 53.2v282.8s10.8 97.1-100.4 90.1l-60.2-12.9-14.2 57.1S882.5 880 903.7 680.2c21.3-200-5.2-327.3-5.2-327.3z m-707.4 18.3l-45.4 69.7 83.6 52.1s56 28.5 29.4 81.9C233.8 625.5 112 736.3 112 736.3l109 68.1c75.4-163.7 70.5-142 89.5-200.7 19.5-60.1 23.7-105.9-9.4-139.1-42.4-42.6-47-46.6-110-93.4z"
};
// 下拉列表项
const list_items=["百度","微信","抖音","哔哩哔哩","淘宝"];
// 图标模板
const iconTemplate=(path)=>{
return `
`;
}
// 下拉列表项模板
const listItemTemplate=(text,translate_value)=>{
return `
`;
}
// 生成下拉列表项
const renderListItems=()=>{
dropdown_list.innerHTML+=list_items.map((item,index)=>{
return listItemTemplate(item,100*index);
}).join("");
}
// 在页面加载事件中执行生成下拉列表项
window.addEventListener("load",()=>{
renderListItems();
})
// 设置自定义属性的值
const setDropdownProps=(deg,ht,opacity)=>{
root.style.setProperty("--rotate-arrow",deg!==0?deg+"deg":0);
root.style.setProperty("--dropdown-height",ht!==0?ht+"rem":0);
root.style.setProperty("--list-opacity",opacity);
}
// 下拉按钮点击事件
main_button.addEventListener("click",()=>{
const list_wrapper_sizes=3.5;
const dropdown_open_height=4.6*list_items.length+list_wrapper_sizes;
const curr_dropdown_height=root.style.getPropertyValue("--dropdown-height")||"0";
curr_dropdown_height==="0"?setDropdownProps(180,dropdown_open_height,1):setDropdownProps(0,0,0);
})
// 下拉列表项鼠标移入事件
dropdown_list.addEventListener("mouseover",(e)=>{
const translate_value=e.target.dataset.translateValue;
console.log(translate_value)
root.style.setProperty("--translate-value",translate_value);
})
// 下拉列表项点击事件
dropdown_list.addEventListener("click",(e)=>{
const clicked_item_text=e.target.innerText.toLowerCase().trim();
const clicked_item_icon=icons[clicked_item_text];
dropdown_title_icon.innerHTML=iconTemplate(clicked_item_icon);
dropdown_title.innerHTML=clicked_item_text;
setDropdownProps(0,0,0);
})
// 下拉列表项鼠标移动事件
dropdown_list.addEventListener("mousemove",(e)=>{
const icon_size=root.style.getPropertyValue("--floating-icon-size")||0;
const x=e.clientX-dropdown_list.getBoundingClientRect().x;
const y=e.clientY-dropdown_list.getBoundingClientRect().y;
const targetText=e.target.innerText.toLowerCase().trim();
const hover_item_text=icons[targetText];
floating_icon.innerHTML=iconTemplate(hover_item_text);
root.style.setProperty("--floating-icon-left",x-icon_size/2+"px");
root.style.setProperty("--floating-icon-top",y-icon_size/2+"px");
})