Ios 来自调试器的消息：由于内存问题而终止

我的应用程序正在使用

Geojson

文件。我用于将

MGLPolyline

添加到地图。但问题是我的文件太大，因此应用程序崩溃并从调试器获得错误：

消息：由于内存问题而终止

。在第一个循环中，我遇到了66234个对象。我尝试将数组分块到新数组，但没有成功。请帮我解决这个问题。这是我在地图上绘制的代码，这是我的，如果有任何不同的第三方可以解决我的问题，也欢迎使用：

func drawPolyline() {

    // Parsing GeoJSON can be CPU intensive, do it on a background thread
    DispatchQueue.global(qos: .background).async {
        // Get the path for example.geojson in the app's bundle
        let jsonPath = Bundle.main.path(forResource: "KMLMAPNew", ofType: "json")
        let jsonData = NSData(contentsOfFile: jsonPath!)

        do {
            // Load and serialize the GeoJSON into a dictionary filled with properly-typed objects
            guard let jsonDict = try JSONSerialization.jsonObject(with: jsonData! as Data, options: []) as? Dictionary<String, AnyObject>, let features = jsonDict["features"] as? Array<AnyObject> else{return}

            for feature in features {
                guard let feature = feature as? Dictionary<String, AnyObject>, let geometry = feature["geometry"] as? Dictionary<String, AnyObject> else{ continue }

                if geometry["type"] as? String == "LineString" {
                    // Create an array to hold the formatted coordinates for our line
                    var coordinates: [CLLocationCoordinate2D] = []

                    if let locations = geometry["coordinates"] as? Array<AnyObject> {
                        // Iterate over line coordinates, stored in GeoJSON as many lng, lat arrays
                        for location in locations {
                            // Make a CLLocationCoordinate2D with the lat, lng
                            if let location = location as? Array<AnyObject>{
                                let coordinate = CLLocationCoordinate2DMake(location[1].doubleValue, location[0].doubleValue)

                                // Add coordinate to coordinates array
                                coordinates.append(coordinate)
                            }
                        }
                    }

                    let line = MGLPolyline(coordinates: &coordinates, count: UInt(coordinates.count))

                    // Optionally set the title of the polyline, which can be used for:
                    //  - Callout view
                    //  - Object identification
                    line.title = "Crema to Council Crest"

                    // Add the annotation on the main thread
                    DispatchQueue.main.async {
                        // Unowned reference to self to prevent retain cycle
                        [unowned self] in
                        self.mapboxView.addAnnotation(line)
                    }
                }
            }
        }
        catch
        {
            print("GeoJSON parsing failed")
        }
    }
}

func drawPolyline（）{
//解析GeoJSON可能是CPU密集型的，在后台线程上进行
DispatchQueue.global（qos:.background）.async{
//获取应用程序包中example.geojson的路径
让jsonPath=Bundle.main.path（forResource:“KMLMAPNew”，类型为：“json”）
让jsonData=NSData（contentsOfFile:jsonPath！）
做{
//将GeoJSON加载并序列化到充满正确类型对象的字典中
guard let jsonDict=try JSONSerialization.jsonObject（使用：jsonData！作为数据，选项：[]）作为字典，让features=jsonDict[“features”]作为数组else{return}
对于要素中的要素{
guard let feature=feature as？Dictionary，let geometry=feature[“geometry”]as？Dictionary else{continue}
如果几何体[“键入”]为？字符串==“LineString”{
//创建一个数组来保存线的格式化坐标
变量坐标：[CLLocationCoordinate2D]=[]
如果让位置=几何体[“坐标”]作为数组{
//迭代线坐标，存储在GeoJSON中，尽可能多的lng、lat数组
对于位置中的位置{
//与lat、lng协调定位
如果let location=location as？数组{
让坐标=CLLocationCoordinate2DMake（位置[1]。双值，位置[0]。双值）
//将坐标添加到坐标数组
坐标。追加（坐标）
}
}
}
let line=MGLPolyline（坐标：&coordinates，计数：UInt（coordinates.count））
//（可选）设置多段线的标题，该标题可用于：
//-详图索引视图
//-物体识别
line.title=“Crema至议会徽章”
//在主线程上添加注释
DispatchQueue.main.async{
//无主引用到self以防止保留循环
[无主的自己]在
self.mapboxView.addAnnotation（行）
}
}
}
}
抓住
{
打印（“GeoJSON解析失败”）
}
}
}

编辑：：@Alessandro Ornano和@fragilecat非常感谢。但这些解决方案仍然无法解决iPad上应用程序的终止问题。我认为更改当前代码以使其正常工作非常困难，因为数据太大了。我想我需要另一个与大数据相关的解决方案。比如将数组分块到小数组中，然后按队列加载它们。但我不知道如何开始：(

---

我向MapBox的支持团队发送了一封电子邮件，征求建议。

第一个解决方案

可能您的for循环无限运行，每次都将内存分配给一个具有nil值的数组。它使用了大量内存，因此会产生此错误

请在for循环中打印一些内容进行检查

第二种解决方案

将此添加到didReceiveMemoryWarning中：

NSURLCache.sharedURLCache().removeAllCachedResponses()
NSURLCache.sharedURLCache().diskCapacity = 0
NSURLCache.sharedURLCache().memoryCapacity = 0

您还可以更改

NSURLRequest

的缓存策略：

let day_url = NSURL(string: "http://www.example.com")
let day_url_request = NSURLRequest(URL: day_url,
    cachePolicy: NSURLRequestCachePolicy.ReloadIgnoringLocalAndRemoteCacheData,
    timeoutInterval: 10.0)

let day_webView = UIWebView()
day_webView.loadRequest(day_url_request)

---

有关缓存策略的更多信息。

这里的问题与有效的内存管理有关。您正在通过json文件加载大量数据。您意识到您需要在后台队列（线程）上完成大部分工作但是，问题是如何在当前版本的

drawPolyline（）中通过
DispatchQueue.main.async
函数更新UI

method根据第一个循环中对象的数量，您在后台队列和主队列之间切换66234次。此外，您还创建了相同数量的

CLLocationCoordinate2D

数组

这会导致巨大的内存占用。您没有提到有关如何渲染线条的任何要求。因此，如果我们重新构造

drawPolyline（）

方法为

CLLocationCoordinate2D

数组使用一个实例变量，因此我们只使用一个实例变量，然后在更新UI之前处理所有json文件。内存使用量下降到更易于管理的664.6 MB

当然，渲染可能不是您想要的，如果是这种情况，您可能希望将

CLLocationCoordinate2D

数组重新构造为更合适的数据结构

下面是您的

ViewController

类，它将

drawPolyline（）重写为
drawPolyline2（）

导入UIKit
导入映射框
类ViewController:UIViewController、MGLMapViewDelegate{
@IBMOutlet var mapboxView:MGLMapView！
fileprivate变量坐标=[[CLLocationCoordinate2D]]（）
fileprivate var jsonData:NSData？
重写func viewDidLoad（）{
super.viewDidLoad（）
//加载视图后，通常从nib执行任何其他设置。
mapboxView=MGLMapView（帧：view.bounds）
mapboxView.autoresizingMask=[.flexibleWidth、.flexibleHeight]
//mapboxView.setCenter（CLLocationCoordinate2D）（纬度：45.507
import UIKit
import Mapbox

class ViewController: UIViewController, MGLMapViewDelegate {

@IBOutlet var mapboxView: MGLMapView!


fileprivate var coordinates = [[CLLocationCoordinate2D]]()
fileprivate var jsonData: NSData?

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    mapboxView = MGLMapView(frame: view.bounds)
    mapboxView.autoresizingMask = [.flexibleWidth, .flexibleHeight]

    // mapboxView.setCenter(CLLocationCoordinate2D(latitude: 45.5076, longitude: -122.6736),
    //                             zoomLevel: 11, animated: false)

    mapboxView.setCenter(CLLocationCoordinate2D(latitude: 1.290270, longitude: 103.851959),
                         zoomLevel: 11, animated: false)


    view.addSubview(self.mapboxView)


    mapboxView.delegate = self
    mapboxView.allowsZooming = true

    drawPolyline2()
    //newWay()
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}



func drawPolyline2() {

    DispatchQueue.global(qos: .background).async {

        if let path = Bundle.main.path(forResource: "KMLMAPNew", ofType: "json") {
            let fileURL = URL(fileURLWithPath: path)
            if let data = try? Data(contentsOf: fileURL) {

                do {

                    let dictionary = try JSONSerialization.jsonObject(with: data as Data, options: []) as? Dictionary<String, AnyObject>

                    if let features = dictionary?["features"] as? Array<AnyObject> {

                        print("** START **")

                        for feature in features {
                            guard let feature = feature as? Dictionary<String, AnyObject>, let geometry = feature["geometry"] as? Dictionary<String, AnyObject> else { continue }

                            if geometry["type"] as? String == "LineString" {
                                // Create an array to hold the formatted coordinates for our line

                                if let locations = geometry["coordinates"] as? Array<AnyObject> {
                                    // Iterate over line coordinates, stored in GeoJSON as many lng, lat arrays

                                    var featureCoordinates = [CLLocationCoordinate2D]()

                                    for location in locations {
                                        // Make a CLLocationCoordinate2D with the lat, lng
                                        if let location = location as? Array<AnyObject>{
                                            let coordinate = CLLocationCoordinate2DMake(location[1].doubleValue, location[0].doubleValue)

                                            // Add coordinate to coordinates array
                                            featureCoordinates.append(coordinate)
                                        }
                                    }

                                    // Uncomment if you need to store for later use.
                                    //self.coordinates.append(featureCoordinates)

                                    DispatchQueue.main.async {
                                        let line = MGLPolyline(coordinates: &featureCoordinates, count: UInt(featureCoordinates.count))

                                        // Optionally set the title of the polyline, which can be used for:
                                        //  - Callout view
                                        //  - Object identification
                                        line.title = "Crema to Council Crest"
                                        self.mapboxView.addAnnotation(line)

                                    }


                                }

                            }

                        }

                        print("** FINISH **")

                    }

                } catch {
                    print("GeoJSON parsing failed")
                }
            }
        }
    }
}


func drawSmallListObj(list: [Dictionary<String, AnyObject>]){
    for obj in list{
        //            print(obj)
        if let feature = obj as? Dictionary<String, AnyObject> {
            if let geometry = feature["geometry"] as? Dictionary<String, AnyObject> {
                if geometry["type"] as? String == "LineString" {
                    // Create an array to hold the formatted coordinates for our line
                    var coordinates: [CLLocationCoordinate2D] = []

                    if let locations = geometry["coordinates"] as? Array<AnyObject> {
                        // Iterate over line coordinates, stored in GeoJSON as many lng, lat arrays
                        for location in locations {
                            // Make a CLLocationCoordinate2D with the lat, lng
                            if let location = location as? Array<AnyObject>{
                                let coordinate = CLLocationCoordinate2DMake(location[1].doubleValue, location[0].doubleValue)

                                // Add coordinate to coordinates array
                                coordinates.append(coordinate)
                            }
                        }
                    }

                    let line = MGLPolyline(coordinates: &coordinates, count: UInt(coordinates.count))

                    // Optionally set the title of the polyline, which can be used for:
                    //  - Callout view
                    //  - Object identification
                    line.title = "Crema to Council Crest"

                    // Add the annotation on the main thread
                    DispatchQueue.main.async {
                        // Unowned reference to self to prevent retain cycle
                        [unowned self] in
                        self.mapboxView.addAnnotation(line)
                    }
                }
            }
        }
    }
}
func mapView(_ mapView: MGLMapView, alphaForShapeAnnotation annotation: MGLShape) -> CGFloat {
    // Set the alpha for all shape annotations to 1 (full opacity)
    return 1
}

func mapView(_ mapView: MGLMapView, lineWidthForPolylineAnnotation annotation: MGLPolyline) -> CGFloat {
    // Set the line width for polyline annotations
    return 2.0
}

func mapView(_ mapView: MGLMapView, strokeColorForShapeAnnotation annotation: MGLShape) -> UIColor {
    // Give our polyline a unique color by checking for its `title` property
    if (annotation.title == "Crema to Council Crest" && annotation is MGLPolyline) {
        // Mapbox cyan
        return UIColor(red: 59/255, green:178/255, blue:208/255, alpha:1)
    }
    else
    {
        return UIColor.red
    }
}


}

DispatchQueue.main.async {
      // weaked reference to self to prevent retain cycle
      [weak self] in
      guard let strongSelf = self else { return } 
      strongSelf.mapboxView.addAnnotation(line)
}

func drawPolyline() {
        DispatchQueue.global(qos: .background).async {
            [weak self] in
            guard let strongSelf = self else { return }
            let jsonPath = Bundle.main.path(forResource: "KMLMAPNew", ofType: "json")
            let jsonData = NSData(contentsOfFile: jsonPath!)
            do {
                guard let jsonDict = try JSONSerialization.jsonObject(with: jsonData! as Data, options: []) as? Dictionary<String, AnyObject>, let features = jsonDict["features"] as? Array<AnyObject> else{return}
                for feature in features {
                    guard let feature = feature as? Dictionary<String, AnyObject>, let geometry = feature["geometry"] as? Dictionary<String, AnyObject> else{ continue }
                    if geometry["type"] as? String == "LineString" {
                        var coordinates: [CLLocationCoordinate2D] = []
                        if let locations = geometry["coordinates"] as? Array<AnyObject> {
                            for location in locations {
                                if let location = location as? Array<AnyObject>{
                                    let coordinate = CLLocationCoordinate2DMake(location[1].doubleValue, location[0].doubleValue)
                                    coordinates.append(coordinate)
                                }
                            }
                        }
                        let line = MGLPolyline(coordinates: &coordinates, count: UInt(coordinates.count))
                        line.title = "Crema to Council Crest"
                        print(feature) // Added this line just for debug to see the flow..
                        DispatchQueue.main.async {
                            strongSelf.mapboxView.addAnnotation(line)
                        }
                    }
                }
            }
            catch
            {
                print("GeoJSON parsing failed")
            }
        }
    }

func newWay(){
        DispatchQueue.global(qos: .background).async {
            [weak self] in
            guard let strongSelf = self else { return }
            let jsonPath = Bundle.main.path(forResource: "KMLMAPNew", ofType: "json")
            let jsonData = NSData(contentsOfFile: jsonPath!)
            do {
                if let jsonDict = try JSONSerialization.jsonObject(with: jsonData! as Data, options: []) as? Dictionary<String, AnyObject> {
                    if let features = jsonDict["features"] as? Array<AnyObject> {
                        let chunks = stride(from: 0, to: features.count, by: 2).map {
                            Array(features[$0..<min($0 + 2, features.count)])
                        }
                        for obj in chunks{
                            strongSelf.drawSmallListObj(list: obj as! [Dictionary<String, AnyObject>])
                        }
                    }
                }
            }
            catch
            {
                print("GeoJSON parsing failed")
            }
        }
    }

func drawSmallListObj(list: [Dictionary<String, AnyObject>]){
        for obj in list{
            if let feature = obj as? Dictionary<String, AnyObject> {
                if let geometry = feature["geometry"] as? Dictionary<String, AnyObject> {
                    if geometry["type"] as? String == "LineString" {
                        var coordinates: [CLLocationCoordinate2D] = []
                        if let locations = geometry["coordinates"] as? Array<AnyObject> {
                            for location in locations {
                                if let location = location as? Array<AnyObject>{
                                    let coordinate = CLLocationCoordinate2DMake(location[1].doubleValue, location[0].doubleValue)
                                    coordinates.append(coordinate)
                                }
                            }
                        }
                        let line = MGLPolyline(coordinates: &coordinates, count: UInt(coordinates.count))
                        line.title = "Crema to Council Crest"
                        DispatchQueue.main.async {
                            [weak self] in
                            guard let strongSelf = self else { return }
                            strongSelf.mapboxView.addAnnotation(line)
                        }
                    }
                }
            }
        }
    }

func loopALot() {
    for _ in 0 ..< 5000 {
        let image = NSImage(contentsOfFile: filename)
    }
}

func loopALot() {
    for _ in 0 ..< 5000 {
      autoreleasepool {
        let image = NSImage(contentsOfFile: filename)
      }
    }
}