使用 pngdata 转换图像会导致应用程序冻结然后崩溃

Question

我正在使用以下代码将图像转换为数据以将它们存储在核心数据中，但是由于运行内存不足导致应用程序崩溃。该应用程序也被冻结，直到代码完成

    DispatchQueue.main.async {
        let fetchRequest: NSFetchRequest<Project> = Project.fetchRequest()
        fetchRequest.sortDescriptors = [NSSortDescriptor(key: "name", ascending: true)]
        do {
            let results = try self.appData.moc.fetch(fetchRequest)
            let fileManager = FileManager.default
            for project in results {
                NSLog("Project Name: \(String(describing: project.name))")
                if let mainPic = project.mainPicture {
                    if let mainPicName = mainPic.pictureName {
                        let imagePath = (NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as NSString).appendingPathComponent(mainPicName)
                        if fileManager.fileExists(atPath: imagePath) {
                            if let image : UIImage = UIImage(contentsOfFile: imagePath) {
                                let imageData = image.pngData()
                            }
                        }
                    }
                }
            }
        } catch {
            print("Fetching Failed")
        }
        self.appData.saveContext()
        NSLog("13 Ran")
    }

如果我注释掉 let imageData = image.pngData() 行，那么我就不会遇到问题

注释掉该行后，应用程序加载后的内存使用量小于 100MB，如果不注释它会达到 1.15GB，然后再回到大约 150MB。

Answer 1

我认为这是内存问题。

获取了多少个项目？

您可以将代码更改为：

DispatchQueue.main.async {
    let fetchRequest: NSFetchRequest<Project> = Project.fetchRequest()
    fetchRequest.sortDescriptors = [NSSortDescriptor(key: "name", ascending: true)]
    do {
        let results = try self.appData.moc.fetch(fetchRequest)
        let fileManager = FileManager.default


        for project in results {
            autoreleasepool {
            NSLog("Project Name: \(String(describing: project.name))")
            if let mainPic = project.mainPicture {
                if let mainPicName = mainPic.pictureName {
                    let imagePath = (NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as NSString).appendingPathComponent(mainPicName)
                    if fileManager.fileExists(atPath: imagePath) {
                        if let image : UIImage = UIImage(contentsOfFile: imagePath) {
                            let imageData = image.pngData()
                        }
                    }
                }
            }
            }
        }

    } catch {
        print("Fetching Failed")
    }
    self.appData.saveContext()
    NSLog("13 Ran")
}

我觉得应该没问题

使用 pngdata 转换图像会导致应用程序冻结然后崩溃

Converting Image using pngdata causes app to freeze then crash

swift

uiimage