<el-select v-model="listOption.brand" filterable placeholder="品牌名称"  :filter-method="brandKeyChange">
              <el-option
                v-for="item in BrandListData"
                :key="item.id"
                :label="item.brand"
                :value="item.brand">
              </el-option>
            </el-select>

filter-method在输入时触发

brandKeyChange:function(inputKey){
        //inputKey为当前输入的数据
        this.gob.getBrandListData(this,inputKey,(list)=>{//根据输入的数据请求，得到的结果作为渲染的下拉数据
          this.BrandListData=list;
      })
  },