建议不要将大图像保存为UserDefaults。 UserDefaults旨在保存非常小的数据,例如用户首选的应用程序主题颜色。也许一个合适的选择是将你的图像保存在文档目录中。这里是一个功能,可以让你保存图像:
func saveImage(image: UIImage) -> String {
let imageData = NSData(data: UIImagePNGRepresentation(image)!)
let paths = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true)
let docs = paths[0] as NSString
let uuid = NSUUID().uuidString + ".png"
let fullPath = docs.appendingPathComponent(uuid)
_ = imageData.write(toFile: fullPath, atomically: true)
return uuid
}
上述功能将为您创建保存图像的名称。如果你喜欢指定要节省那么你可以做下面的图像的名称(但你将负责确保您指定的图像名称是唯一的):
func saveImage(image: UIImage, withName name: String) {
let imageData = NSData(data: UIImagePNGRepresentation(image)!)
let paths = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true)
let docs = paths[0] as NSString
let name = name
let fullPath = docs.appendingPathComponent(name)
_ = imageData.write(toFile: fullPath, atomically: true)
}
来检索这些图像,就可以图像名称传递给该函数:
func getImage(imageName: String) -> UIImage? {
var savedImage: UIImage?
if let imagePath = getFilePath(fileName: imageName) {
savedImage = UIImage(contentsOfFile: imagePath)
}
else {
savedImage = nil
}
return savedImage
}
依赖于该功能的工作:
func getFilePath(fileName: String) -> String? {
let nsDocumentDirectory = FileManager.SearchPathDirectory.documentDirectory
let nsUserDomainMask = FileManager.SearchPathDomainMask.userDomainMask
var filePath: String?
let paths = NSSearchPathForDirectoriesInDomains(nsDocumentDirectory, nsUserDomainMask, true)
if paths.count > 0 {
let dirPath = paths[0] as NSString
filePath = dirPath.appendingPathComponent(fileName)
}
else {
filePath = nil
}
return filePath
}
这里是你将如何现在保存图像代替邻为例f UserDefaults。我保存图像我会打电话给“图片”:
saveImage(image: Photo.image, withName name: "Image")
下面是我如何检索保存图像时的例子:
if let theSavedImage = getImage(imageName: "Image") {
//I got the image
}
首先,'UserDefaults'是你应该存放大文件的最后一个地方。其次,'synchronize()'大多是无意义的。第三,你可能想使用'CoreData'来存储图像/数据 –
为什么你需要将它保存在UserDefaults中?这不是UserDefaults应该使用的。 – totiG
@ Mr.Xcoder如何使用CoreData保存和加载图像? – Rombond