     let list = []
        for (let i = 0; i < num; i++) {
          let lng = 120.38105869 + Math.random() * 0.5
          let lat = 31.10115627 + Math.random() * 0.5
          list.push(new DC.Position(lng, lat))
        }
        return list
      }
      DC.config.baseUrl = '../libs/dc-sdk/resources/'
      let viewer = new DC.Viewer('viewer-container')
      let baseLayer = DC.ImageryLayerFactory.createImageryLayer(
        DC.ImageryType.AMAP,
        {
          style: 'img',
          crs: 'WGS84',
