分享-2023年资深前端进阶：前端登顶之巅-最全面的前端知识点梳理总结，前端之巅

*分享一个使用比较久的🪜

技术框架公司的选型(老项目)：vue2 + iview-ui
方案的实现思路是共性的，展现UI样式需要你们自定义进行更改；因为iview是全局注入，基本使用原先的类名进行二次创建公共组件，修改基础js实现逻辑；

需求分析：实现远程滚动加载数据的穿梭框
1、创建自定义穿梭框，分左侧和右侧数据
2、依赖后端接口，左侧是左侧数据，右侧是右侧数据
3、定义好出入参数，支持回显内容及选中内容的去重处理
4、绑定对应的v-model数据响应
5、滚动加载数据，区分左右区域；添加自定义指令进行监听
6、滚动加载数据，不丢失已选中的数据，或去重已选中数据
7、支持左右侧的远程搜索功能，左右互不影响，检索数据放组件外部进行

1、代码信息

创建ivu-transfer.vue文件；依赖iviewUI请依据自己的样式进行拷贝；

1.1 自定义滚动监听指令

/** 远程滚动加载 */
import Vue from 'vue'

Vue.directive("loadTransfer", {
  bind(el, binding) {
    const select_dom = el.querySelectorAll('.ivu-transfer-list .ivu-transfer-list-content');
    select_dom.forEach((item, index) => {
      item.addEventListener('scroll', function () {
        const height = this.scrollHeight - this.scrollTop - 1 <= this.clientHeight;
        if (height) {
          binding.value(index)
        }
      })
    })
  }
})

1.2 自定义穿梭框代码

<template>
  <div class="ivu-transfer">
    <div
      class="ivu-transfer-list"
      :style="{
        width: listStyle.width,
        height: listStyle.height
      }"
    >
      <div class="ivu-transfer-list-header">
        <Checkbox
          :value="checkLeftAll"
          @on-change="handleAllLeftCheck"
        ></Checkbox>
        <span class="ivu-transfer-list-header-title">源列表</span>
        <span class="ivu-transfer-list-header-count">
          {{ leftDataSource.length }}
        </span>
      </div>
      <div class="ivu-transfer-list-body">
        <div class="ivu-transfer-list-content">
          <CheckboxGroup v-model="checkLeftAllGroup">
            <Checkbox
              :key="index"
              :label="item.value"
              class="ivu-transfer-list-content-item"
              v-for="(item, index) in leftDataSource"
              >{{
                item.label +
                  `${item.description ? ` - ${item.description}` : ""}`
              }}</Checkbox
            >
          </CheckboxGroup>
          <div
            v-if="!leftDataSource.length"
            class="ivu-transfer-list-content-not-found"
          >
            列表为空
          </div>
        </div>
      </div>
    </div>
    <div class="ivu-transfer-operation">
      <Button
        size="small"
        type="primary"
        icon="ios-arrow-back"
        @click="handleClickArrowBack"
        :disabled="!checkRightAllGroup.length"
      ></Button>
      <Button
        size="small"
        type="primary"
        icon="ios-arrow-forward"
        @click="handleClickArrowForward"
        :disabled="!checkLeftAllGroup.length"
      ></Button>
    </div>
    <div
      class="ivu-transfer-list"
      :style="{
        width: listStyle.width,
        height: listStyle.height
      }"
    >
      <div class="ivu-transfer-list-header">
        <Checkbox
          :value="checkRightAll"
          @on-change="handleAllRightCheck"
        ></Checkbox>
        <span class="ivu-transfer-list-header-title">目的列表</span>
        <span class="ivu-transfer-list-header-count">
          {{ rightDataSource.length }}
        </span>
      </div>
      <div class="ivu-transfer-list-body">
        <div class="ivu-transfer-list-content">
          <CheckboxGroup v-model="checkRightAllGroup">
            <Checkbox
              :key="index"
              :label="item.value"
              class="ivu-transfer-list-content-item"
              v-for="(item, index) in rightDataSource"
              >{{
                item.label +
                  `${item.description ? ` - ${item.description}` : ""}`
              }}
            </Checkbox>
          </CheckboxGroup>
          <div
            v-if="!rightDataSource.length"
            class="ivu-transfer-list-content-not-found"
          >
            列表为空
          </div>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
const methods = {
  // 点击左侧全选
  handleAllLeftCheck() {
    this.checkLeftAll = !this.checkLeftAll;
    if (this.checkLeftAll) {
      this.checkLeftAllGroup = this.leftDataSource.map(item => item.value);
    } else {
      this.checkLeftAllGroup = [];
    }
  },

  // 点击右侧全选
  handleAllRightCheck() {
    this.checkRightAll = !this.checkRightAll;
    if (this.checkRightAll) {
      this.checkRightAllGroup = this.rightDataSource.map(item => item.value);
    } else {
      this.checkRightAllGroup = [];
    }
  },

  // 点击向右数据
  handleClickArrowBack() {
    this.moveCheckedData("left");
  },

  // 点击向左数据
  handleClickArrowForward() {
    this.moveCheckedData("right");
  },

  moveCheckedData(direction) {
    const newLeftDataSource = [];
    const newRightDataSource = [];

    const dataSource =
      direction === "left" ? this.rightDataSource : this.leftDataSource;

    dataSource.forEach(item => {
      const index =
        direction === "left"
          ? this.checkRightAllGroup.indexOf(item.value)
          : this.checkLeftAllGroup.indexOf(item.value);

      if (index !== -1) {
        direction === "left"
          ? newLeftDataSource.push(item)
          : newRightDataSource.push(item);
      } else {
        direction === "left"
          ? newRightDataSource.push(item)
          : newLeftDataSource.push(item);
      }
    });

    this.leftDataSource =
      direction === "left"
        ? [...this.leftDataSource, ...newLeftDataSource]
        : newLeftDataSource;
    this.rightDataSource =
      direction === "left"
        ? newRightDataSource
        : [...this.rightDataSource, ...newRightDataSource];

    this.checkLeftAll = false;
    this.checkRightAll = false;
    this.checkLeftAllGroup = [];
    this.checkRightAllGroup = [];
    this.$emit("on-change", this.leftDataSource, this.rightDataSource, direction);
  },

  filterDataMethods() {
    const rightValues = new Set(this.rightDataSource.map(opt => opt.value));
    this.leftDataSource = this.leftDataSource.filter(
      item => !rightValues.has(item.value)
    );
    this.$nextTick(() => {
      const leftValues = new Set(this.leftDataSource.map(opt => opt.value));
      this.rightDataSource = this.rightDataSource.filter(
        opt => !leftValues.has(opt.value)
      );
    });
  }
};

export default {
  props: {
    listStyle: {
      type: Object,
      default: () => ({
        width: "250px",
        height: "380px"
      })
    },
    leftData: {
      type: Array,
      require: true,
      default: () => []
    },
    rightData: {
      type: Array,
      require: true,
      default: () => []
    }
  },

  data() {
    return {
      checkLeftAll: false,
      checkRightAll: false,
      checkRightAllGroup: [],
      checkLeftAllGroup: [],
      leftDataSource: [],
      rightDataSource: []
    };
  },

  watch: {
    leftData(newVal) {
      this.leftDataSource = newVal;
      this.filterDataMethods();
    },

    rightData(newVal) {
      this.rightDataSource = newVal || [];
      this.filterDataMethods();
    }
  },

  mounted() {
    this.$nextTick(() => {
      this.$emit("on-change", this.leftDataSource, this.rightDataSource);
    })
  },

  methods
};
</script>

<style lang="less" scoped>
.ivu-transfer-list-content-item {
  width: 100%;
  margin-left: -0.3em;
}

.ivu-transfer-list-content-not-found {
  display: block;
}
</style>

2、内容使用api介绍

1、树形结构入参：dataSource=[{label: '测试',value: 1, description: '拼接内容' }]，
2、标签引用：<IvuTransfer :leftData="dataSource" :rightData="targetKeys" @on-change="handleChange" v-loadTransfer="handleLoadMore" />
3、相关api说明文档在文章底部

<template>
 <div class="customSearch">
    <Input
      search
      clearable
      v-model="formLeftInput"
      placeholder="请输入搜索内容"
      @on-clear="handleOnLeftInput"
      @on-search="handleOnLeftInput"
    />
    <div style="width: 50px"></div>
    <Input
      search
      clearable
      v-model="formRightInput"
      placeholder="请输入搜索内容"
      @on-clear="handleOnRightInput"
      @on-search="handleOnRightInput"
    />
    </div>
    <IvuTransfer
      :leftData="dataSource"
      :rightData="targetKeys"
      @on-change="handleChange"
      v-loadTransfer="handleLoadMore"
    />
 </template>
// 远程滚动加载
  handleLoadMore(index) {
    if (index === 0 && this.dataLeftHasMore && !this.isShowLoading) {
      this.curLeftPage++;
      this.getLeftMockData();
    }
    if (index === 1 && this.dataRightHasMore && !this.rightLoading) {
      this.curRightPage++;
      this.getRightTargetKeys();
    }
  },
  
  // 触发选中移动
  handleChange(newLeftTargetData, newRightTargetKeys, direction) {
    this.dataSource = [...newLeftTargetData];
    this.targetKeys = [...newRightTargetKeys];
    if (direction === "right") {
      return this.remoteCheckPage();
    }
    if (direction === "left") {
      return this.remoteRightCheckPage();
    }
  },

getLeftData() {},
getRightData() {}

参数	说明	类型	默认值	必填项
leftData	[{}]-label,value结构	Array[]	[]	是
rightData	[{}]-label,value结构	Array[]	[]	是
on-change	数据变更触发	newLeft，newRight, direction	无	否