在CoreData中保存旋转图像并显示旋转图像的步骤如下:
以下是一个示例代码,演示了如何在CoreData中保存旋转图像并显示旋转图像:
// 创建数据模型
class ImageEntity: NSManagedObject {
@NSManaged var imageData: Data?
@NSManaged var rotationAngle: Float
}
// 保存旋转图像
func saveRotatedImage(image: UIImage, rotationAngle: Float) {
guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {
return
}
let managedContext = appDelegate.persistentContainer.viewContext
let entity = NSEntityDescription.entity(forEntityName: "ImageEntity", in: managedContext)!
let imageEntity = NSManagedObject(entity: entity, insertInto: managedContext) as! ImageEntity
imageEntity.imageData = image.jpegData(compressionQuality: 1.0)
imageEntity.rotationAngle = rotationAngle
do {
try managedContext.save()
} catch let error as NSError {
print("Could not save image. \(error), \(error.userInfo)")
}
}
// 显示旋转图像
func displayRotatedImage() {
guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {
return
}
let managedContext = appDelegate.persistentContainer.viewContext
let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "ImageEntity")
do {
let results = try managedContext.fetch(fetchRequest) as! [ImageEntity]
if let imageEntity = results.first, let imageData = imageEntity.imageData {
let image = UIImage(data: imageData)
let rotationAngle = CGFloat(imageEntity.rotationAngle)
let rotatedImage = image?.rotate(by: rotationAngle) // 自定义的旋转方法
// 在界面上显示旋转后的图像
imageView.image = rotatedImage
}
} catch let error as NSError {
print("Could not fetch image. \(error), \(error.userInfo)")
}
}
这是一个简单的示例,演示了如何在CoreData中保存旋转图像并显示旋转图像。在实际应用中,可能需要根据具体需求进行适当的修改和扩展。
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