el-table点击button获取所有选中状态复选框的值

1、<el-table>标签写入 ref="multipleTable"

2、<el-table-column>标签写入 type="selection"

3、<el-button>标签写入 @click=""

4、methods中button对应的click事件方法中写入 this.$refs.multipleTable.selection

<el-table :data="tableData" ref="multipleTable">
  <el-table-column type="selection" width="50"></el-table-column>
  <el-table-column label="Key" property="key" width="300">
    <template slot-scope="scope">
      <el-input v-model="scope.row.key" placeholder="请输入key"/>
    </template>
  </el-table-column>
  <el-table-column label="Value" property="value" width="300">
    <template slot-scope="scope">
      <el-input v-model="scope.row.value" placeholder="请输入Value"/>
    </template>
  </el-table-column>
</el-table>
<el-button type="primary" @click="tj()">提交</el-button>


methods:{
  tj(){
      console.log(this.$refs.multipleTable.selection)
    }
}