ios - Google Maps SDK 导致 iOS 7 泄露

Question

加载谷歌地图时在分析器中获取泄漏。我根据谷歌的示例代码创建了一个非常简单的 View Controller ，我发现我在加载 map 时遇到了泄漏。我相信泄漏是在 SDK 本身。有没有人遇到过这个问题并找到了解决方案？

基本 View Controller

//
//  JRCViewController.m
//  GoogleMapsInterface
//
//  Created by Jake Cunningham on 15/01/2014.
//  Copyright (c) 2014 Jake Cunningham. All rights reserved.
//

#import "JRCViewController.h"

@interface JRCViewController (){
BOOL firstLocationUpdate_;
GMSMapView *mapView;
}


@end


@implementation JRCViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.
    GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:-33.868
                                                            longitude:151.2086
                                                                 zoom:6];
    mapView = [GMSMapView mapWithFrame:CGRectZero camera:camera];

    [mapView addObserver:self
               forKeyPath:@"myLocation"
                  options:NSKeyValueObservingOptionNew
                  context:NULL];

    self.view = mapView;

    dispatch_async(dispatch_get_main_queue(), ^{
        mapView.myLocationEnabled = YES;
    });

}


- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)observeValueForKeyPath:(NSString *)keyPath
                      ofObject:(id)object
                        change:(NSDictionary *)change
                       context:(void *)context {

    if (!firstLocationUpdate_) {
        // If the first location update has not yet been recieved, then jump to that
        // location.
        firstLocationUpdate_ = YES;
        CLLocation *location = [change objectForKey:NSKeyValueChangeNewKey];
        mapView.camera = [GMSCameraPosition cameraWithTarget:location.coordinate
                                                        zoom:14];
    }
}



@end

Answer 1

我找到了问题的原因。像你一样，我认为他们的“演示代码”应该按原样工作。不明白这一行

GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:-33.868
                                                            longitude:151.2086
                                                                 zoom:6];

演示中的第一行实际上就是问题所在。 如果你不在澳大利亚(这是这个位置点所在的地方) 您导致将整个世界地图(图 block )加载到应用程序的内存中，这是错误的!

如果您大致知道您的 map 将被用于哪个大陆/国家/州 或者更好!在显示 map 之前获取用户的位置，并在该位置加载 map 。

所以你对 map 的初始化应该是这样的:

CLLocation *location = [self getUserLocation];//可能来自共享首选项，即使它距离用户实际所在位置 100 英里，也比加载另一个大陆要好。

然后你的 viewDidLoad 看起来像这样

- (void)viewDidLoad
{
    [super viewDidLoad];
     CLLocation *location = [self getUserLocation]; //<== very important!
    // Do any additional setup after loading the view, typically from a nib.
    GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:location.coordinate.latitude
                                                            longitude:location.coordinate.longitude
                                                                 zoom:15];
    mapView = [GMSMapView mapWithFrame:CGRectZero camera:camera];

    [mapView addObserver:self
               forKeyPath:@"myLocation"
                  options:NSKeyValueObservingOptionNew
                  context:NULL];

    self.view = mapView;

    dispatch_async(dispatch_get_main_queue(), ^{
        mapView.myLocationEnabled = YES;
    });

}

缩放级别对此也有影响 -> 缩放越大，加载到内存中的图 block 越少。

我还在 viewWillDisappear 中添加了代码(假设当再次需要给定的 ViewController 时 viewDidLoad 将再次运行)

-(void)viewWillDisappear:(BOOL)animated{
    [super viewWillDisappear:animated];
        [self.mapView clear];
        [self.mapView removeFromSuperview] ;
        self.mapView.delegate = nil;
        self.mapView = nil ;
}

这帮助我的应用程序从必须使用 140 MB 的内存减少到仅 56! 当应用正常值介于 40 和 45 之间时。