MAMapKit 点聚合
- 高德官网申请Key.
- 阅读开发指南.
- 工程基于iOS 3D地图SDK实现
- 关键词：点聚合 => h5入口:https://lbs.amap.com/api/javascript-api/guide/overlays/massmarker/
- 关键词：ios聚合 ios入口:https://lbs.amap.com/dev/demo/cluster-marker#iOS
| 类 | 接口 | 说明 | 版本 |
|---|---|---|---|
| AnnotationClusterViewController | - (void)searchPoiWithKeyword:(NSString *)keyword; | 根据关键字搜索poi点 | n/a |
| CoordinateQuadTree | - (void)buildTreeWithPOIs:(NSArray *)pois; | 根据返回poi建树 | n/a |
| AnnotationClusterViewController | - (void)addAnnotationsToMapView:(MAMapView *)mapView; | 把annotation添加到地图 | n/a |
| AnnotationClusterViewController | - (void)mapView:(MAMapView *)mapView regionDidChangeAnimated:(BOOL)animated; | 响应地图区域变化回调，刷新annotations | n/a |
- 调用ClusterAnnotation文件夹下的代码能够实现poi点聚合，使用步骤如下：
- 初始化coordinateQuadTree。
Objective-C
self.coordinateQuadTree = [[CoordinateQuadTree alloc] init]; Swift
var coordinateQuadTree = CoordinateQuadTree() - 获得poi数组pois后，创建coordinateQuadTree。
- 项目Demo通过关键字搜索获得poi数组数据，具体见工程。此处从获得poi数组开始说明。
- 创建四叉树coordinateQuadTree来建立poi的四叉树索引。
- 创建过程较为费时，建议另开线程。创建四叉树完成后，计算当前mapView下需要显示的annotation。
Objective-C
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ /* 建立四叉树. */ [self.coordinateQuadTree buildTreeWithPOIs:respons.pois]; dispatch_async(dispatch_get_main_queue(), ^{ /* 计算当前mapView区域内需要显示的annotation. */ NSLog(@"First time calculate annotations."); [self addAnnotationsToMapView:self.mapView]; }); });Swift
DispatchQueue.global(qos: .default).async(execute: { [weak self] in self?.coordinateQuadTree.build(withPOIs: response.pois) self?.shouldRegionChangeReCalculate = true self?.addAnnotations(toMapView: (self?.mapView)!) }) - 根据CoordinateQuadTree四叉树索引，计算当前zoomLevel下，mapView区域内的annotation。
Objective-C
- (void)addAnnotationsToMapView:(MAMapView *)mapView { /* 判断是否已建树. */ if (self.coordinateQuadTree.root == nil) { return; } /* 根据当前zoomLevel和zoomScale 进行annotation聚合. */ double zoomScale = self.mapView.bounds.size.width / self.mapView.visibleMapRect.size.width; /* 基于先前建立的四叉树索引，计算当前需要显示的annotations. */ NSArray *annotations = [self.coordinateQuadTree clusteredAnnotationsWithinMapRect:mapView.visibleMapRect withZoomScale:zoomScale andZoomLevel:mapView.zoomLevel]; /* 更新annotations. */ [self updateMapViewAnnotationsWithAnnotations:annotations]; }Swift
func addAnnotations(toMapView mapView: MAMapView) { synchronized(lock: self) { [weak self] in guard (self?.coordinateQuadTree.root != nil) || self?.shouldRegionChangeReCalculate != false else { NSLog("tree is not ready.") return } guard let aMapView = self?.mapView else { return } let visibleRect = aMapView.visibleMapRect let zoomScale = Double(aMapView.bounds.size.width) / visibleRect.size.width let zoomLevel = Double(aMapView.zoomLevel) DispatchQueue.global(qos: .default).async(execute: { [weak self] in let annotations = self?.coordinateQuadTree.clusteredAnnotations(within: visibleRect, withZoomScale: zoomScale, andZoomLevel: zoomLevel) self?.updateMapViewAnnotations(annotations: annotations as! Array<ClusterAnnotation>) }) } } - 更新annotations。对比mapView里已有的annotations，吐故纳新。
Objective-C
/* 更新annotation. */ - (void)updateMapViewAnnotationsWithAnnotations:(NSArray *)annotations { /* 用户滑动时，保留仍然可用的标注，去除屏幕外标注，添加新增区域的标注 */ NSMutableSet *before = [NSMutableSet setWithArray:self.mapView.annotations]; [before removeObject:[self.mapView userLocation]]; NSSet *after = [NSSet setWithArray:annotations]; /* 保留仍然位于屏幕内的annotation. */ NSMutableSet *toKeep = [NSMutableSet setWithSet:before]; [toKeep intersectSet:after]; /* 需要添加的annotation. */ NSMutableSet *toAdd = [NSMutableSet setWithSet:after]; [toAdd minusSet:toKeep]; /* 删除位于屏幕外的annotation. */ NSMutableSet *toRemove = [NSMutableSet setWithSet:before]; [toRemove minusSet:after]; /* 更新. */ dispatch_async(dispatch_get_main_queue(), ^{ [self.mapView addAnnotations:[toAdd allObjects]]; [self.mapView removeAnnotations:[toRemove allObjects]]; }); }Swift
func updateMapViewAnnotations(annotations: Array<ClusterAnnotation>) { /* 用户滑动时，保留仍然可用的标注，去除屏幕外标注，添加新增区域的标注 */ let before = NSMutableSet(array: mapView.annotations) before.remove(mapView.userLocation) let after: Set<NSObject> = NSSet(array: annotations) as Set<NSObject> /* 保留仍然位于屏幕内的annotation. */ var toKeep: Set<NSObject> = NSMutableSet(set: before) as Set<NSObject> toKeep = toKeep.intersection(after) /* 需要添加的annotation. */ let toAdd = NSMutableSet(set: after) toAdd.minus(toKeep) /* 删除位于屏幕外的annotation. */ let toRemove = NSMutableSet(set: before) toRemove.minus(after) DispatchQueue.main.async(execute: { [weak self] () -> Void in self?.mapView.addAnnotations(toAdd.allObjects) self?.mapView.removeAnnotations(toRemove.allObjects) }) } <UIViewController>AnnotationClusterViewControllerpoi点聚合PoiDetailViewController显示poi详细信息列表
MAAnnotationViewClusterAnnotationView自定义的聚合annotationView
Conform to <MAAnnotation>ClusterAnnotation记录annotation的信息，如其代表的poi数组、poi的个数、poi平均坐标，并提供两个annotation是否Equal的判断
CoordinateQuadTree封装的四叉树类QuadTree四叉树基本算法
