下面我的快捷代码将2张单独的图像保存到核心数据中。我想做的是,当用户在文本字段enter 1中键入1时,输入到核心数据中的第一个图像出现在imaegview图片上。如果键入2,则第二张图像出现在imageview上。我的代码基于此,而不是二进制数据。我在pic.image = user.image遇到编译错误,指出无法分配类型为“ Data”的值?键入“ UIImage?”。 https://github.com/redrock34/be
import UIKit
import CoreData
class ViewController: UIViewController,UITextFieldDelegate {
@IBOutlet var labelName : UILabel!
@IBOutlet var enterT : UITextField!
@IBOutlet var pic : UIImageView!
lazy var context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
var dx = [UIImage]()
var names = [String]()
override func viewDidLoad() {
super.viewDidLoad()
enterT.delegate = self
pic.backgroundColor = .cyan
guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else { return }
let managedContext = appDelegate.persistentContainer.viewContext
let entity = NSEntityDescription.entity(forEntityName: "Users", in: managedContext)!
let item = NSManagedObject(entity: entity, insertInto: managedContext)
let item2 = NSManagedObject(entity: entity, insertInto: managedContext)
let fetch = NSFetchRequest<NSFetchRequestResult>(entityName: "Users")
let vex = UIImage(named: "on.jpg")?.pngData()
if let data = vex{
item.setValue(data, forKey: "image")
}
let vex2 = UIImage(named: "house.jpg")?.pngData()
if let data2 = vex2{
item2.setValue(data2, forKey: "image")
}
do {
let result = try? managedContext.fetch(fetch) as? [Users]
print("Queen",result?.count)
try? managedContext.save()
}
catch {
print("Could not save")
}
}
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
guard let text = (textField.text as? NSString)?.replacingCharacters(in: range, with: string), let index = Int(text) else { //here....
// display an alert about invalid text
return true
}
save(at: index )
return true
}
func save(at index : Int) {
let fetchRequest = NSFetchRequest<Users>(entityName: "Users")
fetchRequest.predicate = NSPredicate(format: "idx == %d", Int32(index))
do {
if let user = try context.fetch(fetchRequest).first {
pic.image = user.image
}
} catch {
print("Could not fetch \(error) ")
}
return
}
@IBAction func add(){
fetch()
}
func fetch()
{
for i in 0..<dx.count {
let newUser = Users(context: context)
newUser.username = names[i]
newUser.idx = Int32(i + 1)
}
print("Storing Data..")
do {
try context.save()
} catch {
print("Storing data Failed", error)
}
return
}
}
您需要将Data类型的图像转换为如下所示的UIImage。
UIImage(data: user.image ?? Data())