实体实例将多种形式的可视化聚合到一个高级对象中。它们可以手动创建并添加到 Viewer#entities 或由数据源生成，例如 CzmlDataSource 和 GeoJsonDataSource 。

 一、Entity-增加

//方法一
var entity =  viewer.entities.add({ id : 'uniqueId' }); 

//方法二
var entity = viewer.entities.getOrCreateEntity('uniqueId');

二、Entity-删除

//方法一，先查后删
var entity = viewer.entities.getById('uniqueId'); 
viewer.entities.remove(entity) 
//方法二，直接删除
viewer.entities.removeById('uniqueId') 
//方法三，删除所有
viewer.entities.removeAll()

三、Entity-查找

var entity = viewer.entities.getById('uniqueId');

四、Entity-修改

// 获取标注
const getEntitys = () => {
  const viewer = window.viewer;
  const handle3D = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);
  // 单击左键显示弹窗
  handle3D.setInputAction((movement) => {
    const pick = viewer.scene.pick(movement.position);
    if (Cesium.defined(pick)) {
     pick.id.label.text = '修改后的标注',
     image: pick.id.billboard.image = './static/images/markers/5.png'
    }
  }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
};

五、获取Entity中的属性

const getEntitys = (viewer) => {
  const handle3D = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);
  // 单击左键显示弹窗
  handle3D.setInputAction((movement) => {
    const pick = viewer.scene.pick(movement.position);
    if (Cesium.defined(pick)) {
      viewerData.pointForm = {
        id: pick.id.id,
        label: pick.id.label.text.getValue(),
        image: pick.id.billboard.image.getValue(),
      };
    }
  }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
};