HarmonyOS 地图添加marker

参考demo：

import { MapComponent, mapCommon, map } from '@kit.MapKit';
import { AsyncCallback } from '@kit.BasicServicesKit';
@Entry
@Component
struct MarkerDemo {
  private mapOptions?: mapCommon.MapOptions;
  private mapController?: map.MapComponentController;
  private callback?: AsyncCallback<map.MapComponentController>;
  private marker?: map.Marker;

  aboutToAppear(): void {
    // 地图初始化参数
    this.mapOptions = {
      position: {
        target: {
          latitude: 31.984410259206815,
          longitude: 118.76625379397866
        },
        zoom: 15
      }
    };
    this.callback = async (err, mapController) => {
      if (!err) {
        this.mapController = mapController;
        // Marker初始化参数
        let markerOptions: mapCommon.MarkerOptions = {
          position: {
            latitude: 31.984410259206815,
            longitude: 118.76625379397866
          },
          rotation: 0,
          visible: true,
          zIndex: 0,
          alpha: 1,
          anchorU: 0.5,
          anchorV: 1,
          clickable: true,
          draggable: true,
          flat: false
        };
        // 创建Marker
        this.marker = await this.mapController.addMarker(markerOptions);
        // 设置标记可拖拽
        this.marker.setDraggable(true);
        // 设置标记锚点
        this.marker.setMarkerAnchor(1.0, 1.0);
        // 设置信息窗的标题
        this.marker.setTitle('南京');
        // 设置信息窗的子标题
        this.marker.setSnippet('华东地区');
        // 设置信息窗的锚点位置
        this.marker.setInfoWindowAnchor(1, 1);
        // 设置信息窗可见
        this.marker.setInfoWindowVisible(true);
      }
    };
  }
  build() {
    Stack() {
      Column() {
        MapComponent({ mapOptions: this.mapOptions, mapCallback: this.callback });
      }.width('100%')
    }.height('100%')
  }
}