场景：往地图中加载500个点位，并通过regionchange监听地图scale的改变，实现marker随地图的放大而放大 结果： iOS很丝滑。安卓卡顿，频繁进行缩放操作会死机 <map class="map" id="mapId" :scale="scale" :longitude="center.longitude" :latitude="center.latitude" :rotate="rotate" :enable-rotate="true" :enable-poi="poi" :enable-building="building" :enable-scroll="scroll" :enable-overlooking="overlooking" :polygons="polygons" :polyline="polyline" :markers="markers" @tap="handleMapTap" @regionchange="regionchange" > </map>  //hasCarList = [...] // 500条数据 //data scaleMap: { 16: [5, 10], 17: [8, 16], 18: [12, 25], 19: [18, 37], 20: [25, 50] } // script regionchange: debounce(function ({ type, detail, causedBy }) { const that = this if (!['scale'].includes(causedBy)) return if (type === 'end') { let scale = detail.scale // const scaleRatio = setScaleRatio(scale) // console.log(scale) that.addCarOverLayer({ scale, rotate: detail.rotate }) } }, 300), // script addCarOverLayer ({ rotate = 0, scale = ORIGIN_SCALE }) { const that = this // that.isAddCarOverlay = true let _width = 5// scaleRatio > 0 ? 5 * scaleRatio : Math.abs(scaleRatio / 5) let _height = 10// scaleRatio > 0 ? 10 * scaleRatio : Math.abs(scaleRatio / 10) if (scale < 17) { _width = that.scaleMap[16][0] _height = that.scaleMap[16][1] } else if (scale > 17 && scale < 18) { _width = that.scaleMap[17][0] _height = that.scaleMap[17][1] } else if (scale > 18 && scale < 19) { _width = that.scaleMap[18][0] _height = that.scaleMap[18][1] } else if (scale > 19 && scale < 20) { _width = that.scaleMap[19][0] _height = that.scaleMap[19][1] } else if (scale === 20) { _width = that.scaleMap[20][0] _height = that.scaleMap[20][1] } // console.log(_width, _height) // if (_width < 1) { // _width = parseInt(_width) // _height = parseInt(_height) // } // let _data = storeMarkers?.filter(item => item.platenumber) || [] const _data = hasCarList.map((item) => ({ longitude: item.longitude, latitude: item.latitude, iconPath: item.iconPath, width: _width, height: _height, rotate: rotate + item.rotate, id: item.id, anchor: { x: 0.5, y: 0.5 } })) _data.length && that.mapContext.addMarkers({ markers: _data }) // that.splitBatch(_data) },

地图组件里有提到建议通过wx.createSelectorQuery获取mapcontex，请问具体怎么获取，有参考代码吗