<template>
  <el-tree
    ref="tree"
    :data="data"
    show-checkbox
    default-expand-all
    node-key="id"
    highlight-current
    :props="defaultProps"
    check-on-click-node
  />

  <div class="buttons">
    <el-button @click="getCheckedNodes">通过 node 获取</el-button>
    <el-button @click="getCheckedKeys">通过 key 获取</el-button>
    <el-button @click="setCheckedNodes">通过 node 设置</el-button>
    <el-button @click="setCheckedKeys">通过 key 设置</el-button>
    <el-button @click="resetChecked">清空</el-button>
  </div>
</template>

<script>
export default {

  data() {
    return {
      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',
      },
    }
  },
  methods: {
    getCheckedNodes() {
      console.log(this.$refs.tree.getCheckedNodes())
    },
    getCheckedKeys() {
      console.log(this.$refs.tree.getCheckedKeys())
    },
    setCheckedNodes() {
      this.$refs.tree.setCheckedNodes([{
        id: 5,
        label: '二级 2-1',
      }, {
        id: 9,
        label: '三级 1-1-1',
      }])
    },
    setCheckedKeys() {
      this.$refs.tree.setCheckedKeys([3])
    },
    resetChecked() {
      this.$refs.tree.setCheckedKeys([])
    },
  },
}
</script>
