Google map生成热力图

谷歌地图SDK的iOS端 在2017年出了新的API，可以生成热力图，下面就教大家如何生成热力图

首先需要添加谷歌地图及热力图支持SDK，目前我用的cocoapods添加

pod 'GoogleMaps'

pod 'Google-Maps-iOS-Utils'

然后pod install就可以集成谷歌地图了

添加谷歌地图

    self.mapView = [[GMSMapView alloc] init];

    self.mapView.settings.rotateGestures = NO;

    self.mapView.settings.tiltGestures = NO;

    self.mapView.settings.allowScrollGesturesDuringRotateOrZoom = NO;

    self.mapView.myLocationEnabled = YES;

    self.mapView.delegate = self;

创建热力图Layer

self.heatMapLayer = [[GMUHeatmapTileLayer alloc] init];

    NSMutableArray* colors = @[].mutableCopy;

    [colorsaddObject:[MUAppHelper colorWithHexString:@"#FFD800"]];

    [colorsaddObject:[MUAppHelper colorWithHexString:@"#F03F05"]];

//赋值热力图的权重色值，权重从低到高

    self.heatMapLayer.gradient = [[GMUGradient alloc] initWithColors:colors startPoints:@[@0.01,@0.5] colorMapSize:256];

//透明度，设置太高会遮住地图，太低会看不清

    self.heatMapLayer.opacity =0.7;

//热力图半径，设置太高热力图会比较大，根据需求来自己调吧

    self.heatMapLayer.radius =25;

紧接着就要获取热力图数据了。获取的是经纬度和权重,统一添加到数组中，赋值给heatMapLayer的数据中。

由于数据量可能比较大，所以我们使用多线程处理数据，处理完毕后主线程刷新UI

NSOperationQueue* queue = [NSOperationQueue new];

    NSBlockOperation* operation = [NSBlockOperation blockOperationWithBlock:^{

        NSMutableArray* locationArr =@[].mutableCopy;

        for (HeatMapLocation* location in self.locationCollection.orderCoordinates) {

//将经纬度和权重添加到数组中。intensity是权重

            [locationArr addObject:[[GMUWeightedLatLng alloc] initWithCoordinate:CLLocationCoordinate2DMake(location.lat, location.lon) intensity:0.666]];

        }

        for (HeatMapLocation* location in self.locationCollection.cancelCoordinates) {

            [locationArr addObject:[[GMUWeightedLatLng alloc] initWithCoordinate:CLLocationCoordinate2DMake(location.lat, location.lon) intensity:1]];

        }

        for (HeatMapLocation* location in self.locationCollection.openCoordinates) {

            [locationArr addObject:[[GMUWeightedLatLng alloc] initWithCoordinate:CLLocationCoordinate2DMake(location.lat, location.lon) intensity:0.333]];

        }

        //GMUWeightedLatLng

        dispatch_async(dispatch_get_main_queue(), ^{

            self.heatMapLayer.weightedData = locationArr;

            self.heatMapLayer.map =self.mapView;

        });

    }];

    [queue addOperation:operation];

添加完毕后就会发现热力图已经显示了

如图