CSS实现自适应菜单

妖狐艹你老母 2022-04-01 03:10 458阅读 0赞

### CSS实现自适应左侧菜单 ###

*  先看效果图
 *  菜单需要的数据结构
 *   *  实现代码js(react)
     *  css部分
 *  总结

# 先看效果图 #

![效果图][20181228200530759.gif_pic_center]

# 菜单需要的数据结构 #

[{ 
        name: 'xxx0',
        children: [
          { 
            name: "xxx01"
          }
        ],
      }, { 
        name: 'xxx1',
        children: [],
    }]

## 实现代码js(react) ##

import React from 'react'
    import PropTypes from 'prop-types'
    
    import styles from "./MenuNow.less"
    
    class Menu extends React.Component { 
    
      static propTypes = { 
        navOpenKeys: PropTypes.array,
        changeOpenKeys: PropTypes.func,
        location: PropTypes.object,
        menu: PropTypes.array.isRequired
      }
    
      render() { 
        const { 
          menu: data = [],
          location = { },
          navOpenKeys = () => { },
          changeOpenKeys = () => { },
        } = this.props;
          // 递归生成菜单
          const getItems = (data) => { 
            if(!data.length) { 
              return <div className="menu-list">
                <a style={ {  color: "rgb(125, 00, 00)"}}>
                  ( ⊙ o ⊙ )null！
                </a>
              </div>
            }
            return data.map((item, index) => { 
              if (item.children) { 
                let isOpenThis = navOpenKeys.some(value => item.uuid == value);
                return (
                  <div
                    key={ item.uuid}
                    className={  "menu-wrapper" + (isOpenThis ? 
                    " menu-wrapper-active" : "") }
                  >
                    <span
                      style={ {  top: index * 44 }}
                      onClick={ 
                        () => { 
                          let newNavOpenKeys = [...navOpenKeys];
                          let findIndex = newNavOpenKeys.findIndex(
    						value => value == item.uuid)
                          if(findIndex > -1) { 
                            newNavOpenKeys.splice(findIndex, 1);
                            return changeOpenKeys(newNavOpenKeys);
                          }
                          newNavOpenKeys.push(item.uuid + "");
                          changeOpenKeys(newNavOpenKeys);
                        }
                      }
                    >
                      { item.name}
                      <span 
                      	style={ 
                      		{ 
                      			 transform: isOpenThis ?  
                      				"" : "rotate(180deg)" 
                      		}
                      	}>▽</span>
                    </span>
                    <div className="menu-all-wrapper" style={ { }} >
                      <div style={ { 
                        height: isOpenThis ? "auto" : 0,
                        opacity: isOpenThis ? "1" : 0,
                      }}>
                        { getItems(item.children)}
                      </div>
                    </div>
                  </div>
                )
              }
              return (
                <div key={ item.cname}
                  className={  "menu-list " + (name == item.name ? 
                  "menu-list-active" : "") }
                >
                  <Link to={ item.route || '#'} >
                    { item.icon && <Icon type={ item.icon} />}
                    { item.cname}
                  </Link>
                </div>
              )
            })
          }
          const menuItems = getItems(data);
    
          return (
            <div className={ styles.menu_auto}>
              { menuItems}
            </div>
          )
      }
    };
    
    export default Menu

## css部分 ##

.menu_auto { 
      height: 100%;
      position: relative; :global { 
        .menu-wrapper { 
          margin-top: 4px;
          max-height: calc(~"100% - 48px");
          overflow: auto; &.menu-wrapper-active { 
            > span { 
              position: absolute;
              top: 0px;
            }
            .menu-all-wrapper { 
              padding-top: 48px;
            }
          }
          &::-webkit-scrollbar { 
            width: 2px;
            background-color: transparent;
          }
          &::-webkit-scrollbar-thumb { 
            border-top: 40px solid rgba(74, 144, 226, 0.56);
            background-color: #fff;
          }
          > span { 
            width: 100%;
            text-align: center;
            display: block;
            white-space: normal;
            background-color: #7dace3;
            color: #fff;
            line-height: 40px;
            height: 40px;
            cursor: pointer; > span { 
              display: inline-block;
              transition: transform 300ms,
            }
          }
          .menu-all-wrapper { 
            overflow: hidden;
            height: inherit; > div { 
              transition: opacity 0.6s,
            }
          }
    
        }
        .menu-list { 
          overflow: hidden; &.menu-list-active { 
            > a { 
              background: #fff;
              color: #000;
            }
          }
          a { 
            text-align: center;
            color: #fff;
            font-family: PingFangSC-Regular;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
            padding: 0 8px;
            line-height: 40px;
            height: 40px;
            cursor: pointer;
            display: block; &:hover { 
              background: #fff;
              color: #000;
            }
          }
        }
    
      }
    }

# 总结 #

> 滚动条竟然可以有border，神奇

&::-webkit-scrollbar { 
      width: 2px;
      background-color: transparent;
    }
    &::-webkit-scrollbar-thumb { 
      border-top: 40px solid rgba(74, 144, 226, 0.56);
      background-color: #fff;
    }

thanks

[20181228200530759.gif_pic_center]: /images/20220401/7d208d7ddc804f47ad5cdbfadcb7341a.png