我想用核心數據在swift中製作Transformable圖像。 我創建了可變形的imageA。 當我試圖看到數據庫中是否有圖像時,它告訴我們這裏沒有任何東西。 如何將圖像添加到數據庫?我的代碼有什麼問題? 這裏是我的代碼如何在swift中製作Transformable圖像?
我使用方法setImage 和getImage的地方保存和獲取適用於@NSManaged var isSet:NSNumber?
extension AppSettings {
@NSManaged var isSet: NSNumber?
@NSManaged var imageA: UIImage?
}
func setImage(inputAppSettings : AppSettings)
{
let theImage = UIImage(named: "image.png")
inputAppSettings.imageA = theImage
}
func getImage(inputAppSettings : AppSettings)
{
if let theImage = inputAppSettings.imageA
{
print("theImage: \(theImage)")
}
}
類MyTransformer:NSValueTransformer {
override class func allowsReverseTransformation() -> Bool
{
return true
}
class func transformedValue(value:AnyObject) -> AnyObject
{
var returnData:AnyObject = NSData()
let theImage = value as! UIImage
if let theData = UIImagePNGRepresentation(theImage)
{returnData = theData}
return returnData
}
class func reverseTransformedValue(value:AnyObject) -> AnyObject
{
var returnImage:AnyObject = UIImage()
let theData = value as! NSData
if let theImage = UIImage(data: theData)
{returnImage = theImage}
return returnImage
}
override class func transformedValueClass() -> AnyClass
{
return UIImage.self
}
}
func set()
{
if let moc = self.managedObjectContext {
let theAppSettingsAnyObject = NSEntityDescription.insertNewObjectForEntityForName("AppSettings", inManagedObjectContext: moc)
if let theAppSettings = theAppSettingsAnyObject as? AppSettings
{
theAppSettings.isSet = true
self.setImage(theAppSettings)
}
var savingError: NSError?
do {
try moc.save()
} catch let error1 as NSError {
savingError = error1
if let error = savingError{
print("Failed to save . Error = \(error)")
}
}
}
}
謝謝你的回答。但在小圖像的情況下,只有一個圖像來存儲它,我認爲如果我將使用轉換,則代碼會更少,所以我仍然需要這種方式。 – user