需求描述：双击某节点，后端返回与该节点相关联的节点和边（包含该节点本身），仅展开图中不存在的有关联的节点和边。例如左图中，当双击节点【大前端】则返回5个节点，5条边，由于其中4个节点和4条边已存在，则只需要展开1个节点和1条边。

解决方法：

双击某节点，后端返回与该节点相关联的节点和边，需要先去重处理，根据id属性对节点和边进行去重。

数组【nodeExtendArr】表示已扩展的节点，监听节点双击事件，当节点双击时，判断该节点id是否存在数组【nodeExtendArr】中：【if(this.nodeExtendArr.indexOf(id) != -1){...}else{....}】

完整代码：

<template>
  <!-- 动态扩展节点 -->
  <div>
    <!--width,height 画布的宽度，高度。 可以是百分比或像素，一般在dom元素上设置 -->
    <div id="network_id" class="network" style="height:80vh"></div>
  </div>
</template>
<script>
import Vis from "vis";
export default {
  data() {
    return {
      nodes: [],
      edges: [],
      // network:null,
      container: null,
      //   节点数组
      nodesArray: [
        {
          id: 0,
          name: "大前端",
          color: { background: "#fd91b7" },
        },
        {
          id: 1,
          name: "HTML",
          color: { background: "#7ed6df" },
        },
        {
          id: 2,
          name: "JavaScript",
          color: { background: "#d294e2" },
        },
        {
          id: 3,
          name: "CSS",
          color: { background: "#ffb300" },
        },
      ],
      //   关系线数组
      edgesArray: [
        { id: "e1", from: 0, to: 1, label: "ddd" },
        { id: "e2", from: 1, to: 0, label: "aaa" },
        { id: "e3", from: 0, to: 2, label: "step1" },
        { id: "e4", from: 0, to: 3, label: "step1" },
      ],
      options: {},
      data: {},
      nodeExtendArr: [], //已扩展的节点
    };
  },
  mounted() {
    // 初始化
    this.init();
    this.network.moveTo({ scale: 0.8 });
    var param = { nodes: this.nodesArray, edges: this.edgesArray };
    // 创建network
    this.addNetworkParams(param);
    // 鼠标双击事件
    this.network.on("doubleClick", (e) => {
      if (e.nodes.length != 0) {
        console.log(e.nodes[0]);
        //获取需要的参数，获取参数后可到后台获取扩展后的数据
        var id = e.nodes[0];
        console.log(this.nodeExtendArr, this.nodeExtendArr.indexOf(id));
        if (this.nodeExtendArr.indexOf(id) != -1) {
          this.$message.warning("该节点已经扩展");
        } else {
          //每个节点只能扩展一次,nodeExtendArr记录已扩展的节点
          this.nodeExtendArr.push(id);
          // 模拟后端传回的数据
          if (id == "0") {
            param = {
              nodes: [
                {
                  id: 0,
                  name: "大前端",
                  color: { background: "#fd91b7" },
                },
                {
                  id: 1,
                  name: "HTML",
                  color: { background: "#7ed6df" },
                },
                {
                  id: 2,
                  name: "JavaScript",
                  color: { background: "#d294e2" },
                },
                {
                  id: 3,
                  name: "CSS",
                  color: { background: "#ffb300" },
                },
                {
                  id: 4,
                  name: "三大主流框架",
                  color: { background: "#7ed6df" },
                },
              ],
              edges: [
                { id: "e1", from: 0, to: 1, label: "ddd" },
                { id: "e2", from: 1, to: 0, label: "aaa" },
                { id: "e3", from: 0, to: 2, label: "step1" },
                { id: "e4", from: 0, to: 3, label: "step1" },
                { id: "e5", from: 0, to: 4, label: "step1" },
              ],
            };
          }
          //模拟后台获取扩展后的节点
          this.addNetworkParams(param);
        }
      }
    });
    this.network.on("dragEnd", (e) => {
      if (e.nodes && e.nodes.length > 0) {
        // 拖拽节点后,使得节点可以固定不动
        this.network.clustering.updateClusteredNode(e.nodes[0], {
          physics: false,
        });
      }
    });
  },
  methods: {
    //初始化
    init() {
      this.nodes = new Vis.DataSet([]);
      this.edges = new Vis.DataSet([]);
      this.container = document.getElementById("network_id");
      this.data = {
        nodes: this.nodes,
        edges: this.edges,
      };
      this.options = {
        autoResize: true, //网络将自动检测其容器的大小调整，并相应地重绘自身
        locale: "cn", //语言设置：工具栏显示中文
        //设置语言
        locales: {
          cn: {
            //工具栏中文翻译
            edit: "编辑",
            del: "删除当前节点或关系",
            back: "返回",
            addNode: "添加节点",
            addEdge: "添加连线",
            editNode: "编辑节点",
            editEdge: "编辑连线",
            addDescription: "点击空白处可添加节点",
            edgeDescription: "点击某个节点拖拽连线可连接另一个节点",
            editEdgeDescription: "可拖拽连线改变关系",
            createEdgeError: "无法将边连接到集群",
            deleteClusterError: "无法删除集群.",
            editClusterError: "无法编辑群集'",
          },
        },
        // 设置节点样式
        nodes: {
          shape: "dot", //节点的外观。为circle时label显示在节点内，为dot时label显示在节点下方
          size: 30, //节点的大小，
          shadow: false, //如果为true，则节点使用默认设置投射阴影。
          font: {
            //字体配置
            size: 20,
            color: "rgb(117, 218, 167)",
            align: "center",
          },
          color: {
            border: "transparent", //节点边框颜色
            background: "#ffc7c7", //节点背景颜色
            highlight: {
              //节点选中时状态颜色
              border: "rgb(117, 218, 167)",
              background: "rgb(117, 218, 167)",
            },
            hover: {
              //节点鼠标滑过时状态颜色
              border: "#dff9fb",
              background: "#88dab1",
            },
          },
          margin: 5, //当形状设置为box、circle、database、icon、text；label的边距
          widthConstraint: 100, //设置数字，将节点的最小和最大宽度设为该值,当值设为很小的时候，label会换行，节点会保持一个最小值，里边的内容会换行
          borderWidth: 1, //节点边框宽度，单位为px
          borderWidthSelected: 3, //节点被选中时边框的宽度，单位为px
          labelHighlightBold: false, //确定选择节点时标签是否变为粗体
        },
        // 边线配置
        edges: {
          width: 1,
          length: 200,
          color: {
            color: "#848499",
            highlight: "rgb(117, 218, 167)",
            hover: "#88dab1",
            inherit: "from",
            opacity: 1.0,
          },
          font: {
            color: "#343434",
            size: 18, // px
            face: "arial",
            background: "none",
            strokeWidth: 2, // px
            strokeColor: "#ffffff",
            align: "horizontal",
            multi: false,
            vadjust: 0,
            bold: {
              color: "#343434",
              size: 14, // px
              face: "arial",
              vadjust: 0,
              mod: "bold",
            },
            ital: {
              color: "#343434",
              size: 14, // px
              face: "arial",
              vadjust: 0,
              mod: "italic",
            },
            boldital: {
              color: "#343434",
              size: 14, // px
              face: "arial",
              vadjust: 0,
              mod: "bold italic",
            },
            mono: {
              color: "#343434",
              size: 15, // px
              face: "courier new",
              vadjust: 2,
              mod: "",
            },
          },
          shadow: false,
          smooth: {
            //设置两个节点之前的连线的状态
            enabled: true, //默认是true，设置为false之后，两个节点之前的连线始终为直线，不会出现贝塞尔曲线
          },
          arrows: { to: true }, //箭头指向to
        },
        //计算节点之前斥力，进行自动排列的属性
        physics: {
          enabled: true, //默认是true，设置为false后，节点将不会自动改变，拖动谁谁动。不影响其他的节点
          barnesHut: {
            gravitationalConstant: -4000,
            centralGravity: 0.3,
            springLength: 120,
            springConstant: 0.04,
            damping: 0.09,
            avoidOverlap: 0,
          },
        },
        //用于所有用户与网络的交互。处理鼠标和触摸事件以及导航按钮和弹出窗口
        interaction: {
          hover: true,
          dragNodes: true, //是否能拖动节点
          dragView: true, //是否能拖动画布
          hover: true, //鼠标移过后加粗该节点和连接线
          multiselect: true, //按 ctrl 多选
          selectable: true, //是否可以点击选择
          selectConnectedEdges: true, //选择节点后是否显示连接线
          hoverConnectedEdges: true, //鼠标滑动节点后是否显示连接线
          zoomView: true, //是否能缩放画布
        },
        //操作模块:包括 添加、删除、获取选中点、设置选中点、拖拽系列、点击等等
        manipulation: {
          enabled: true, //该属性表示可以编辑，出现编辑操作按钮
          addNode: true,
          addEdge: true,
          // editNode: undefined,
          editEdge: true,
          deleteNode: true,
          deleteEdge: true,
        },
      };
      this.network = new Vis.Network(this.container, this.data, this.options);
    },
    //扩展节点 增加nodes和edges集合参数
    addNetworkParams(param) {
      if (param.nodes && param.nodes.length > 0) {
        //去除已存在的节点  以“id”属性为例删除重复节点，根据具体的属性自行修改
        for (var i in this.network.body.data.nodes._data) {
          var nodeTemp = this.network.body.data.nodes._data[i];
          param.nodes = deleteValueFromArr(param.nodes, "id", nodeTemp.id);
        }
      }
      //添加节点
      for (var i = 0; i < param.nodes.length; i++) {
        var node = param.nodes[i];
        this.nodes.add({
          label: node.name,
          ...node,
        });
      }
      if (param.edges && param.edges.length > 0) {
        //去除已存在的关系  以“id”属性为例删除重复节点，根据具体的属性自行修改
        for (var i in this.network.body.data.edges._data) {
          var edgeTemp = this.network.body.data.edges._data[i];
          param.edges = deleteValueFromArr(param.edges, "id", edgeTemp.id);
        }
      }
      //添加关系
      for (var i = 0; i < param.edges.length; i++) {
        var edge = param.edges[i];
        this.edges.add({
          ...edge,
        });
      }

      //根据对象组数中的某个属性值进行过滤删除
      //arrName数组名  id过滤的字段   keyValue字段值
      function deleteValueFromArr(arrName, id, keyValue) {
        if (arrName == null || arrName.length == 0) {
          return null;
        }
        for (var i = 0; i < arrName.length; i++) {
          if (arrName[i][id] == keyValue) {
            arrName.splice(i, 1);
          }
        }
        return arrName;
      }
    },
  },
};
</script>
<style lang="less">
.circle-option {
  position: absolute;
  left: 0px;
  top: 0px;
  width: 100px;
  height: 100px;
  border: 30px solid rgba(200, 200, 200, 0.7);
  border-radius: 50px;
  box-sizing: border-box;
  z-index: 10;
  display: none;
  span {
    position: absolute;
    left: 0;
    right: 0;
    width: 30px;
    height: 20px;
    line-height: 20px;
    text-align: center;
    font-size: 10px;
    cursor: pointer;
    &:hover {
      color: #1b68ff;
    }
    &:nth-child(1) {
      left: 5px;
      top: -25px;
    }

    &:nth-child(2) {
      left: 37px;
      top: -5px;
    }

    &:nth-child(3) {
      left: 37px;
      top: 25px;
    }

    &:nth-child(4) {
      left: 5px;
      top: 44px;
    }

    &:nth-child(5) {
      left: -27px;
      top: 25px;
    }

    &:nth-child(6) {
      left: -27px;
      top: -5px;
    }
  }
}
</style>

参考文章：vis.js力导向图第三弹——双击扩展节点