ElementUI实现在下拉列表里面进行搜索功能详解

<template>
	<div class="arrbox">
		<!-- 通过visible控制显示还是隐藏 -->
		<el-popover
		v-model="visible"
		placement="bottom-start"
		width="auto"
		>
		<div slot="reference" class="check-select">
			<!-- popper-append-to-body:不需要插入浮动元素,popper-class:设置类名并隐藏 -->
			<el-select
			ref="select"
			v-model="currentval"
			:style="{width:`${width}px`,height:`${height}`}"
			multiple
			:placeholder="placeholder"
			:popper-append-to-body="false"
			popper-class="hide-popper"
			style="width:100%"
			@visible-change="visibleChange"
			@focus="getFocus"
			> <el-option
			v-for="item in selectItem"
			:key="`${item.value}_k`"
			:label="item.label"
			:value="item.value"
			/></el-select>
		</div>
		<!-- selectBxClick让select强制选中 -->
		<div class="selectMain" :style="{'min-width':`${width-20}px`}" @click="selectBxClick">
			<div class="seachButton">
			<el-select
				v-model="seachValue"
				placeholder=" 请选择筛选"
				style="width:70%;margin-right:10px;max-width:195px"
				@visible-change="selectBxClick()"
			>
				<el-option
				v-for="item in seachList"
				:key="item.value"
				:value="item.value"
				:label="item.label"
				/>
			</el-select>
			<div class="btn" @click="seachBtn">搜索</div>
			</div>
			 <div class="selectDiv">
                              <div v-for="item in list.filter(n=>n.value=='all')" :key="item.value" class="list" :class="[currentval.indexOf(item.value)!=-1?'selected':'',item.value=='all'?'allCheck':'']" @click="clickItem(item)">{{ item.label }}</div>

                              <div class="selectDivAuto">
                                <div v-for="item in list.filter(n=>n.value!='all')" :key="item.value" class="list" :class="[currentval.indexOf(item.value)!=-1?'selected':'',item.value=='all'?'allCheck':'']" @click="clickItem(item)">{{ item.label }}</div>
                              </div>

                            </div>
		</div>
		</el-popover>
	</div>
	</template>

// 模拟获取的数据
	const seachClickList = [{value: '1',label: '测试1',type: '1'},{value: '2',label: '测试2',type: '1'},{value: '3',label: '测试3',type: '1'},{value: '4',label: '测试4',type: '2'},{value: '5',label: '测试5',type: '2'},{value: '6',label: '测试6',type: '2'},{value: '7',label: '测试7',type: '2'}]
	export default {
	model: {
		prop: 'parentArr',
		event: 'change-parentArr'
	},
	props: {
		parentArr: {
		type: Array,
		default() {
			return []
		}
		},
		// 传入选中的item,主要时防止list里面没有选中的数据
		parentSelectItem: {
		type: Array,
		default() {
			return []
		}
		},
		width: {
		type: Number,
		default: 300
		},
		height: {
		type: Number,
		default: 30
		},
		placeholder: {
		type: String,
		default: '请输入'
		}
	},
	data() {
		return {
		seachList: [
			{
			value: '1',
			label: '条件一'
			},
			{
			value: '2',
			label: '条件二'
			}
		],
		visible: false,
		currentval: [],
		list: [],
		selectItem: [],
		seachValue: '1'
		}
	},
	watch: {
		seachValue: {
		handler(value) {
			this.getList(value)
		},
		deep: true,
		immediate: true
		},
		parentArr: {
		handler(value) {
			this.currentval = value
		},
		deep: true,
		immediate: true
		},
		parentSelectItem: {
		handler(value) {
			this.selectItem =  value.map(n => {
                              if (n.value == 'all') {
                                n.label = '全部'
                              }
                              return n
                            })
		},
		deep: true,
		immediate: true
		},
		currentval: {
                        handler(value) {
                                this.$emit('change-parentArr', value)
                        }
		}
	},
	created() {
	},
	methods: {
		getList(value) {
                        this.list = [{
                                label: '全部',
                                value: 'all'
                        }, ...seachClickList.filter(n => n.type == value)]
                        this.getSelectItem()
		},
		// 获取选中的item
		getSelectItem() {
                        const noItemList = this.currentval.map(n => {
                                if (this.selectItem.findIndex(i => i.value == n) == -1) {
                                return n
                                }
                                return null
                        }).filter(n => n != null)
                        noItemList.forEach(item => {
                                const index = this.list.findIndex(i => i.value == item)
                                if (index != -1) {
                                this.selectItem.push(this.list[index])
                                }
                        })
		},
		getFocus() {
                        this.visible = true
		},
		visibleChange(data) {
                        this.visible = data
		},
		selectBxClick() {
                        // 避免点击框体时组件消失
                        this.$refs.select.visible = true
		},
		// 选择
		clickItem(item) {
                      const index = this.currentval.indexOf(item.value)
                      if (index == -1) {
                        if (item.value == 'all') {
                          this.currentval = ['all']
                          this.selectItem = [{
                            label: '全部',
                            value: 'all'
                          }]
                        } else {
                          this.currentval.push(item.value)
                          this.selectItem.push(item)
                          const currentvalIndex = this.currentval.indexOf('all')
                          const selectItemIndex = this.selectItem.findIndex(n => n.value == 'all')
                          if (currentvalIndex != -1 && selectItemIndex != -1) {
                            this.selectItem.splice(selectItemIndex, 1)
                            this.currentval.splice(currentvalIndex, 1)
                          }
                        }
                      } else {
                        const itemIndex = this.selectItem.findIndex(n => n.value == item.value)
                        this.selectItem.splice(itemIndex, 1)
                        this.currentval.splice(index, 1)
                      }
                    },
		// 搜索
		seachBtn() {
                        this.getList()
		}
	}
	}

.arrbox {
display: inline-block;
}
.check-select{
::v-deep.hide-popper{
	display: none;
}
}
::v-deep .el-input__suffix{
i:not(.el-select__caret){
	display: none;
}
}
.selectMain {
width: 100%;
height: 100%;
.seachButton{
	width: 100%;
	align-items: center;
	display: flex;
	div.btn{
	width: 25%;
	max-width: 70px;
	max-width: 80px;
	height: 40px;
	display: flex;
	align-items: center;
	justify-content: center;
	font-size: 12px;
	color: #fff;
	background-color: #409EFF;
	border-radius: 5px;
	cursor: pointer;
	}
}
.selectDiv{
        width: 100%;
        max-width: 500px;
        margin-top: 10px;
        padding:  0 10px 0 0;
        .list{
          width: 100%;
          padding: 10px 20px 10px 10px;
          color: #666;
          cursor: pointer;
          position: relative;
          &.selected{
            color: #409EFF;
            &::after{
              position: absolute;
              right: 0px;
              top: 50%;
              transfORM: translateY(-50%);
              font-family: element-icons;
              content: "\e6da";
              font-size: 12px;
              font-weight: 700;
              -WEBkit-font-smoothing: antialiased;
            }
          }
        }
        .selectDivAuto{
          width: calc(100% + 15px);
          max-height: 300px;
          overflow-y: auto;
          .list{
            padding: 10px 30px 10px 10px;
            &.selected::after{
              right: 10px;
            }
          }
        }

      }
}
.allCheck{
border-bottom: 1px solid rgb(228, 225, 225);
}

<template>
	<seachSelectInput v-model="from.tag" :parentSelectItem='selectItem' :width="302" placeholder="请选择标签" />
</template>
<script>
import seachSelectInput from ./seachSelectInput'
export default {
components: {
	seachSelectInput
},
data(){
	return{
		from:{
			tag:['1']
		},
		selectItem:[
			{
			value: '1',
			label: '测试1'
			}
		]
	}
}
}