如何隱藏element-ui中tree懶加載葉子節(jié)點checkbox(分頁懶加載效果)

更新時間：2022年07月21日 10:38:56 作者：騎上我心愛的小摩托

這篇文章主要介紹了如何隱藏element-ui中tree懶加載葉子節(jié)點checkbox(分頁懶加載效果)，具有很好的參考價值，希望對大家有所幫助。如有錯誤或未考慮完全的地方，望不吝賜教

1.首先按照官網

拷貝tree樹組件代碼，設置完show-checkbox，圖中查看更多為葉子節(jié)點，且設置數(shù)據節(jié)點屬性為disabled

<el-tree
      ref="treeRef"
      class="treeDom"
      lazy
      show-checkbox
      :props="defaultProps"
      highlight-current="true"
      :load="lazyLoadMore"
      :expand-on-click-node="false"
      :default-expanded-keys="defaultExpandKeys"
      :default-checked-keys="defaultCheckedKeys"
      node-key="id"
      @node-expand="handleNodeExpand"
      @node-collapse="handleNodeCollapse"
      @node-click="handleNodeClick"
      @check="handleCheck"
    >
      <div slot-scope="{ node, data }" class="custom-tree-node">
        <!-- 查看更多 -->
        <span
          v-if="data.id ==='loadmore'"
          class="tree-node loadmore"
          @click="loadMoreNode(node,data)"
        >
          <el-link>{{ node.label }}</el-link>
        </span>
        <!-- 數(shù)據到底了 -->
        <span
          v-if="data.id ==='disabledload'"
          class="tree-node no-data"
          style="color: #999; cursor: auto;"
        >
          {{ node.label }}
        </span>
        <!-- 普通節(jié)點 -->
        <el-tooltip
          class="item"
          effect="light"
          placement="right-start"
        >
          <div slot="content" style="max-width: 300px;">
            {{ node.label }}
          </div>
          <span v-if="data.id !=='loadmore' && data.id!=='disabledload'" class="span-tree-node" @click="loadMoreNode(node,data)">{{ node.label }}</span>
        </el-tooltip>
      </div>
    </el-tree>

css樣式如下：

::v-deep .span-tree-node {
  width: 120px;
  position: absolute;
  text-overflow: ellipsis;
  overflow: hidden;
  color: #696969;
  top: 50%;
  transform: translateY(-50%);
}
::v-deep .treeDom {
  width: 100%;
  overflow-x: auto;
  .custom-tree-node {
    width: 100% !important;
    position: relative;
  }

2.由于屬性是isleaf

所以lazy狀態(tài)下葉子節(jié)點不會有加載目錄符號，但此時，有個禁用復選框，現(xiàn)在只需要對它設置樣式即可

::v-deep .el-tree .el-tree-node:last-child {
  .el-tree-node__content .is-leaf +.el-checkbox.is-disabled{
    display: none;
  }
  .el-tree-node__content.is-not-clickable{
    cursor: pointer;
  }
}

3. 分頁懶加載實現(xiàn)功能也比較簡單

可以復寫tree樹自帶的load方法，load方法內攜帶兩個返回參數(shù)，一個是node，一個是resolve，即懶加載數(shù)據必須是通過resolve就是return 將數(shù)據帶回

    async lazyLoadMore(node, resolve, parentNode = []) {
      let id = node?.data?.id, pre = node?.data?.name, data = [], arrId = '';
      if (node.level === 0) {
        id = this.paramNode.parent;
        return resolve([{id: id, name: id, leaf: false}]);
      }
      if (node.level === 1) {
        pre = '';
      }
      // 節(jié)點各自的resolve
      this.funcResolve.push({id: id, resolve: resolve});
      this.funcResolve = this.funcResolve.filter((item, index, self)=>{
        return self.findIndex(x=>x.id === item.id) === index;
      });
      // 判斷獲取分頁查詢的pre參數(shù)
      if (id && id.indexOf('/') > -1) {
        let arrIndex = id.lastIndexOf('/') + 1;
        arrId = id.substring(arrIndex);
        if (arrId === pre) pre = '';
      }
      // lazy加載查詢接口
      const { data: {items} } = await getInterfaceTreeDictory({parent: id || '', pre: pre || ''});
      data = items.map(({interface_url: name, full_interface_url: id}) => {
        return {name, id};
      });
      // 翻頁信息添加
      if (data.length >= this.pageSize) {
        let nearName = data[data.length - 1].name;
        data.push({name: '查看更多', id: 'loadmore', nearName: nearName, leaf: true, disabled: true});
      }
      // 查看更多加載需根據各自的resolve加載數(shù)組數(shù)據
      if (parentNode && parentNode.length > 0) {
        parentNode.push(...data);
        return resolve(parentNode);
      } else {
        return resolve(data);
      }
    },
    // 查看更多事件點擊
    loadMoreNode(node, data) {
      if (data.id === 'loadmore') {
        let nodeParentKey = node.parent.key ? node.parent.key : this.paramNode.parent;
        let childNode = {
            data: {
              id: nodeParentKey,
              name: data.nearName
            }
          }, resolve = '';
        let parentNode = node.parent.childNodes.map(({key: id, label: name})=>{
          return { name, id };
        });
        console.log(parentNode);
        // 剔除自定義查看更多option數(shù)據
        if (parentNode.length > 0) {
          parentNode = parentNode.slice(0, -1);
        }
        // 選取resolve返回
        if (parentNode.length <= this.pageSize) {
          resolve = this.funcResolve.filter((item)=>{
            return item.id === nodeParentKey;
          });
          // 調用原生Tree load方法
          this.$refs.treeRef.load(childNode, resolve[0].resolve, parentNode);
        }
      }
    },

代碼內有一點需要注意，即每次查詢接口的時候，和后臺約定的規(guī)則是：不包含分頁，需要傳值兩個參數(shù)，一個是parent，即當前節(jié)點的上一級所有層級拼接，另一個是pre即當前節(jié)點的子集，若第一次加載，pre可為空，若查看更多再一次加載pre為上一次加載數(shù)據data的最后一個元素id，作為傳參；

eg：