鸿蒙运动开发实战：打造 Keep 式轨迹播放效果

前言

在运动类应用中，轨迹播放效果是提升用户体验的关键功能之一。它不仅能直观展示用户的运动路线，还能通过动态效果增强运动的趣味性。Keep 作为一款知名的运动健身应用，其轨迹播放效果深受用户喜爱。那么，如何在鸿蒙系统中开发出类似 Keep 的轨迹播放效果呢？本文将通过实际代码案例，深入解析实现这一功能的关键步骤和技术要点。

效果：

一、核心功能拆解

要实现类似 Keep 的轨迹播放效果，我们需要完成以下几个核心功能：

• 动态轨迹播放：通过定时器和动画效果，实现轨迹的动态播放，模拟用户运动过程。

• 地图交互：在地图上绘制轨迹，并根据播放进度更新地图中心点和旋转角度。

二、动态轨迹播放

1.播放逻辑

通过定时器和动画效果实现轨迹的动态播放。以下是播放轨迹的核心代码：

private playTrack() {// 如果已经在播放，则停止if (this.playTimer) {this.mapController?.removeOverlay(this.polyline);clearInterval(this.playTimer);this.playTimer = undefined;if (this.animationTimer) {clearInterval(this.animationTimer);}if (this.movingMarker) {this.mapController?.removeOverlay(this.movingMarker);this.movingMarker = undefined;}this.currentPointIndex = 0;return;}// 创建动态位置标记this.movingMarker = new Marker({position: this.trackPoints[0],icon: new ImageEntity("rawfile://images/ic_run_detail_start.png"),isJoinCollision: SysEnum.CollisionBehavior.NOT_COLLIDE,located: SysEnum.Located.CENTER});this.mapController?.addOverlay(this.movingMarker);// 开始播放this.playTimer = setInterval(() => {this.currentPointIndex++;if (this.currentPointIndex >= this.trackPoints.length) {clearInterval(this.playTimer);this.playTimer = undefined;this.currentPointIndex = 0;if (this.movingMarker) {this.mapController?.removeOverlay(this.movingMarker);this.movingMarker = undefined;}return;}// 更新动态位置标记位置，使用setInterval实现平滑移动if (this.movingMarker && this.currentPointIndex < this.trackPoints.length - 1) {const currentPoint = this.trackPoints[this.currentPointIndex];const nextPoint = this.trackPoints[this.currentPointIndex + 1];let animationProgress = 0;// 清除之前的动画定时器if (this.animationTimer) {clearInterval(this.animationTimer);}// 创建新的动画定时器，每10ms更新一次位置this.animationTimer = setInterval(() => {animationProgress += 0.1; // 每次增加0.1的进度if (animationProgress >= 1) {clearInterval(this.animationTimer);this.animationTimer = undefined;this.movingMarker?.setPosition(new LatLng(nextPoint.lat, nextPoint.lng));} else {const interpolatedLat = currentPoint.lat + (nextPoint.lat - currentPoint.lat) * animationProgress;const interpolatedLng = currentPoint.lng + (nextPoint.lng - currentPoint.lng) * animationProgress;this.movingMarker?.setPosition(new LatLng(interpolatedLat, interpolatedLng));}}, 10); // 每10ms执行一次}// 绘制当前轨迹线段const currentPoints = this.trackPoints.slice(0, this.currentPointIndex + 1);const currentColors = PathGradientTool.getPathColors(this.record!.points.slice(0, this.currentPointIndex + 1), 100);if (this.polyline) {this.mapController?.removeOverlay(this.polyline);this.polyline.remove();this.polyline.destroy();}this.polyline = new Polyline({points: currentPoints,width: 5,join: SysEnum.LineJoinType.ROUND,cap: SysEnum.LineCapType.ROUND,isGradient: true,colorList: currentColors!});this.mapController?.addOverlay(this.polyline);// 更新地图中心点和旋转角度let bearing = 0;if (this.currentPointIndex < this.trackPoints.length - 1) {const currentPoint = this.trackPoints[this.currentPointIndex];const nextPoint = this.trackPoints[this.currentPointIndex + 1];bearing = Math.atan2(nextPoint.lat - currentPoint.lat,nextPoint.lng - currentPoint.lng) * 180 / Math.PI;bearing = (bearing + 360) % 360;bearing = (360 - bearing + 90) % 360;}this.mapController?.mapStatus.setRotate(bearing).setOverlooking(90).setCenterPoint(new LatLng(this.trackPoints[this.currentPointIndex].lat, this.trackPoints[this.currentPointIndex].lng)).refresh();}, 100); // 每100ms移动一次
}

2.动画效果

通过定时器和线性插值实现动态轨迹的平滑移动效果。以下是动画效果的核心代码：

if (this.movingMarker && this.currentPointIndex < this.trackPoints.length - 1) {const currentPoint = this.trackPoints[this.currentPointIndex];const nextPoint = this.trackPoints[this.currentPointIndex + 1];let animationProgress = 0;// 清除之前的动画定时器if (this.animationTimer) {clearInterval(this.animationTimer);}// 创建新的动画定时器，每10ms更新一次位置this.animationTimer = setInterval(() => {animationProgress += 0.1; // 每次增加0.1的进度if (animationProgress >= 1) {clearInterval(this.animationTimer);this.animationTimer = undefined;this.movingMarker?.setPosition(new LatLng(nextPoint.lat, nextPoint.lng));} else {const interpolatedLat = currentPoint.lat + (nextPoint.lat - currentPoint.lat) * animationProgress;const interpolatedLng = currentPoint.lng + (nextPoint.lng - currentPoint.lng) * animationProgress;this.movingMarker?.setPosition(new LatLng(interpolatedLat, interpolatedLng));}}, 10); // 每10ms执行一次
}

三、地图交互

1.地图中心点和旋转角度更新

在播放轨迹的过程中，动态更新地图的中心点和旋转角度，以确保用户始终能看到当前播放的位置。以下是更新地图中心点和旋转角度的代码：

let bearing = 0;
if (this.currentPointIndex < this.trackPoints.length - 1) {const currentPoint = this.trackPoints[this.currentPointIndex];const nextPoint = this.trackPoints[this.currentPointIndex + 1];bearing = Math.atan2(nextPoint.lat - currentPoint.lat,nextPoint.lng - currentPoint.lng) * 180 / Math.PI;bearing = (bearing + 360) % 360;bearing = (360 - bearing + 90) % 360;
}this.mapController?.mapStatus.setRotate(bearing).setOverlooking(90).setCenterPoint(new LatLng(this.trackPoints[this.currentPointIndex].lat, this.trackPoints[this.currentPointIndex].lng)).refresh();

四、总结

通过上述步骤，我们成功实现了类似 Keep 的轨迹播放效果。不仅提升了用户体验，还为运动数据的可视化提供了有力支持。