el-tree过滤后的数据，选择父节点，仅选中过滤后的子节点

1.实现思路

利用el-tree组件的check-strictly属性，动态更改父节点和子节点的强关联关系；

1.当数据过滤后，将check-strictly设置为true，解除父子节点强关联关系； 2.父节点选中时，通过check事件，递归获取子节点，并将显示的节点属性设置为父节点一样； 3.重置check-strictly为false，使父子节点强关联 4.等待dom更新后，获取所有选中节点，调用setCheckedNodes选中所有节点。

2.直接上demo

提供了html搭配cdn的demo，新建一个html就可以直接查看效果啦！

<!DOCTYPE html>
<html lang="zh">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <link
      rel="stylesheet"
      href="https://unpkg.com/element-ui@2.15.14/lib/theme-chalk/index.css"
    />
    <script src="https://unpkg.com/vue@2/dist/vue.js"></script>
    <script src="https://unpkg.com/element-ui@2.15.14/lib/index.js"></script>
  </head>

  <body>
    <div id="app">
      <el-input placeholder="输入关键字进行过滤" v-model="filterText">
      </el-input>

      <el-tree
        class="filter-tree"
        :data="data"
        :props="defaultProps"
        node-key="id"
        default-expand-all
        show-checkbox
        :check-strictly="checkStrictly"
        :filter-node-method="filterNode"
        @check="handleCheck"
        ref="tree"
      >
      </el-tree>
    </div>
  </body>
  <script>
    var Main = {
      watch: {
        filterText(val) {
          this.checkStrictly = true;
          this.$refs.tree.filter(val);
        },
      },

      methods: {
        filterNode(value, data) {
          if (!value) return true;
          return data.label.indexOf(value) !== -1;
        },
        handleCheck(data) {
          let node = this.$refs.tree.getNode(data);
          let checked = node.checked;
          // 选中当前过滤过后的节点机器所有子节点
          this.setNodeSelectStatus(node, checked);
          this.checkStrictly = false;
          // 选中的节点数据
          const selectedChildNodes = this.$refs.tree.getCheckedNodes(true);
          this.$nextTick(() => {
            // 重新选中所有节点，因父子节点强关联，所以会同步父节点选择状态
            this.$refs.tree.setCheckedNodes(selectedChildNodes);
          });
        },
        setNodeSelectStatus(node, selected) {
          this.$refs.tree.setChecked(node, selected, false);
          if (node.childNodes && node.childNodes.length > 0) {
            node.childNodes.forEach((childNode) => {
              if (childNode.visible) {
                this.setNodeSelectStatus(childNode, selected);
              }
            });
          }
        },
      },

      data() {
        return {
          filterText: "",
          checkStrictly: false,
          data: [
            {
              id: 1,
              label: "一级 1",
              children: [
                {
                  id: 4,
                  label: "二级 1-1",
                  children: [
                    {
                      id: 9,
                      label: "三级 1-1-1",
                    },
                    {
                      id: 10,
                      label: "三级 1-1-2",
                    },
                  ],
                },
              ],
            },
            {
              id: 2,
              label: "一级 2",
              children: [
                {
                  id: 5,
                  label: "二级 2-1",
                },
                {
                  id: 6,
                  label: "二级 2-2",
                },
              ],
            },
            {
              id: 3,
              label: "一级 3",
              children: [
                {
                  id: 7,
                  label: "二级 3-1",
                },
                {
                  id: 8,
                  label: "二级 3-2",
                },
              ],
            },
          ],
          defaultProps: {
            children: "children",
            label: "label",
          },
        };
      },
    };
    var Ctor = Vue.extend(Main);
    new Ctor().$mount("#app");
  </script>
</html>