swift ios数据持久化UIImage

我创建了一个类，如下所示，并希望将数组：[costCategory]保存到磁盘

class costCategory : NSObject, NSCoding {
var name : String
var defaultValue : Int
var thisMonthsEstimate : Int
var sumOfThisMonthsActuals : Int
var riskFactor : Float
var monthlyAverage : Float
var icon: UIImage!

init (name:String, defaultValue:Int, thisMonthsEstimate:Int, sumOfThisMonthsActuals:Int, riskFactor:Float, monthlyAverage:Float, icon: UIImage) {
    self.name = name
    self.defaultValue = defaultValue
    self.thisMonthsEstimate = thisMonthsEstimate
    self.sumOfThisMonthsActuals = sumOfThisMonthsActuals
    self.riskFactor = riskFactor
    self.monthlyAverage = monthlyAverage
    self.icon = icon
}

// MARK: NSCoding

required init(coder decoder: NSCoder) {
    //Error here "missing argument for parameter name in call
    self.name = decoder.decodeObjectForKey("name") as! String
    self.defaultValue = decoder.decodeIntegerForKey("defaultValue")
    self.thisMonthsEstimate = decoder.decodeIntegerForKey("thisMonthsEstimate")
    self.sumOfThisMonthsActuals = decoder.decodeIntegerForKey("sumOfThisMonthsActuals")
    self.riskFactor = decoder.decodeFloatForKey("riskFactor")
    self.monthlyAverage = decoder.decodeFloatForKey("monthlyAverage")
    self.icon = decoder.decodeObjectForKey("icon") as! UIImage!
    super.init()
}

func encodeWithCoder(coder: NSCoder) {
    coder.encodeObject(self.name, forKey: "name")
    coder.encodeInt(Int32(self.defaultValue), forKey: "defaultValue")
    coder.encodeInt(Int32(self.thisMonthsEstimate), forKey: "thisMonthsEstimate")
    coder.encodeInt(Int32(self.sumOfThisMonthsActuals), forKey: "sumOfThisMonthsActuals")
    coder.encodeFloat(self.riskFactor, forKey: "riskFactor")
    coder.encodeFloat(self.monthlyAverage, forKey: "monthlyAverage")
    coder.encodeObject(self.icon, forKey: "icon")
}

}

我将数据保存在viewController中，如下所示：

类ViewController:UIViewController{

@IBOutlet weak var photo: UIImageView!
override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    let defaults = NSUserDefaults.standardUserDefaults()
    let arrayOfObjectsKey = "arrayOfObjectsKey"
    var arrayOfObjects = [costCategory]()
    arrayOfObjects.append(costCategory(name: "Mark", defaultValue: 50, thisMonthsEstimate: 60, sumOfThisMonthsActuals: 70, riskFactor:80, monthlyAverage:90, icon: UIImage(named:"Mark.JPG")!))
    arrayOfObjects.append(costCategory(name: "Mary", defaultValue: 50, thisMonthsEstimate: 60, sumOfThisMonthsActuals: 70, riskFactor:80, monthlyAverage:90, icon: UIImage(named:"Mary.JPG")!))
    var arrayOfObjectsData = NSKeyedArchiver.archivedDataWithRootObject(arrayOfObjects)
    var arrayOfObjectsUnarchivedData = defaults.dataForKey("arrayOfObjectsKey")!
    var arrayOfObjectsUnarchived = NSKeyedUnarchiver.unarchiveObjectWithData(arrayOfObjectsUnarchivedData) as! [costCategory]
    **println(arrayOfObjectsUnarchived[0].icon)**
    **photo.image = arrayOfObjectsUnarchived[0].icon**
}

}

我println（arrayOfObjectsUnarchived[0]。图标）发现它为零，无法获取我保存的原始图像，为什么？并且用下面的方法保存是否足够好？有人有其他方法像文件管理器吗？谢谢

让defaults=NSUserDefaults.standardUserDefaults（）

var arrayofobjectsunarciveddata=defaults.dataForKey（“arrayOfObjectsKey”）

---

var arrayofobjectsunarchiver=NSKeyedUnarchiver.unarchiveObjectWithData（arrayOfObjectsUnarchivedData）为！[costCategory]

将

UIImage

存储在

NSUserDefaults

中不是一个好主意

我建议将图像保存在文件系统中，您可以将其文件系统路径存储在您的模型中，然后将其保存在

NSUserDefaults

但是，如果您真的感兴趣，以下是图像在

NSUserDefaults

中的保存方式：

编写

UIImage

：

let imageData = UIImageJPEGRepresentation(image, 1)
let relativePath = "image_\(NSDate.timeIntervalSinceReferenceDate()).jpg"
let path = self.documentsPathForFileName(relativePath)
imageData.writeToFile(path, atomically: true)
NSUserDefaults.standardUserDefaults().setObject(relativePath, forKey: "path")
NSUserDefaults.standardUserDefaults().synchronize()

let possibleOldImagePath = NSUserDefaults.standardUserDefaults().objectForKey("path") as String?

if let oldImagePath = possibleOldImagePath {
    let oldFullPath = self.documentsPathForFileName(oldImagePath)
    let oldImageData = NSData(contentsOfFile: oldFullPath)
    // here is your saved image:
    let oldImage = UIImage(data: oldImageData)
}

阅读

UIImage

：

let imageData = UIImageJPEGRepresentation(image, 1)
let relativePath = "image_\(NSDate.timeIntervalSinceReferenceDate()).jpg"
let path = self.documentsPathForFileName(relativePath)
imageData.writeToFile(path, atomically: true)
NSUserDefaults.standardUserDefaults().setObject(relativePath, forKey: "path")
NSUserDefaults.standardUserDefaults().synchronize()

let possibleOldImagePath = NSUserDefaults.standardUserDefaults().objectForKey("path") as String?

if let oldImagePath = possibleOldImagePath {
    let oldFullPath = self.documentsPathForFileName(oldImagePath)
    let oldImageData = NSData(contentsOfFile: oldFullPath)
    // here is your saved image:
    let oldImage = UIImage(data: oldImageData)
}

编辑：根据OP请求

步骤1:编写一个方法，该方法采用图像名称并返回文件系统中的图像路径。在这里，我将文件保存在

Documents

目录中

- (NSString *)imagePathForImage:(NSString *)iImageName {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *imagePath = [documentsDirectory stringByAppendingPathComponent:iImageName];

    return imagePath;
}

第2步：调用上述方法并将图像路径保存在您的

成本类别中。我不是在为此编写代码。我希望你能联系到这一点

步骤3:在文件系统上保存图像。传递从上述方法获得的图像和路径

- (void)saveImage:(UIImage *)iImage toPath:(NSString *)iImagePath {
    NSData *imageData = UIImagePNGRepresentation(iImage);
    [imageData writeToFile:iImagePath atomically:NO];
}

步骤4:最后，当您从
NSUserDefaults
读取对象时，获取图像路径属性并调用下面的方法来获取和渲染图像：

- (UIImage *)imageForPath:(NSString *)iImagePath {
    return [UIImage imageWithContentsOfFile:iImagePath];
}

您真的给了我一个提示，将图像保存在文件系统中，并将系统路径存储在我的模型中。我放弃了我最初的想法，在我的模型中保存UIImage。但是你能给我一个简单的代码来演示如何保存它吗？我刚开始学这部分，不熟悉。谢谢看看我的编辑。我希望有帮助！