我有一个自定义结构信息。 对于属性图像(字符串( 我想插入保存图像的文档目录的路径。当我尝试使用 UserDefaults 保存结构数组时,它已成功保存并被检索。但是当我使用路径从文档目录中检索图像时,它显示以下错误: 致命错误:解开可选值包装时意外发现 nil。 当我使用 if-else 块捕获异常时,表视图上不显示任何图像。下面是我的代码:
struct Information{
var image : String
var content : String?
var url : String?
init(image:String,content:String?,url:String?){
self.image = image
self.content = content
self.url = url
}
init(dictionary : [String:String]) {
self.image = dictionary["image"]!
self.content = dictionary["content"]!
self.url = dictionary["url"]!
}
var dictionaryRepresentation : [String:String] {
return ["image" : image, "content" : content!, "url" : url!]
}
}还有我的视图控制器:
override func viewDidAppear(_ animated: Bool) {
savePath()
loadDefaults()
tableView.reloadData()
}
func saveDefaults()
{
let cfcpArray = information.map{ $0.dictionaryRepresentation }
UserDefaults.standard.set(cfcpArray, forKey: "cfcpArray")
}
func loadDefaults()
{
information = (UserDefaults.standard.object(forKey: "cfcpArray") as! [[String:String]]).map{ Information(dictionary:$0) }
for info in information{
print(info)
}
}
func savePath(){
let paths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
// Get the Document directory path
let documentDirectorPath:String = paths[0]
// Create a new path for the new images folder
imagesDirectoryPath = documentDirectorPath + "/ImagePicker"
var objcBool:ObjCBool = true
let isExist = FileManager.default.fileExists(atPath: imagesDirectoryPath, isDirectory: &objcBool)
// If the folder with the given path doesn't exist already, create it
if isExist == false{
do{
try FileManager.default.createDirectory(atPath: imagesDirectoryPath, withIntermediateDirectories: true, attributes: nil)
}catch{
print("Something went wrong while creating a new folder")
}
}
tableView.reloadData()
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
// The info dictionary may contain multiple representations of the image. You want to use the edited.
guard let selectedImage = info[UIImagePickerControllerEditedImage] as? UIImage
else {
fatalError("Expected a dictionary containing an image, but was provided the following: (info)")
}
image = selectedImage
dismiss(animated: true, completion: nil)
saveImage()
}
func saveImage(){
// Save image to Document directory
var imagePath = Date().description
imagePath = imagePath.replacingOccurrences(of: " ", with: "")
imagePath = imagesDirectoryPath + "/(imagePath).png"
path = imagePath
// print(path!)
let data = UIImagePNGRepresentation(image)
let success = FileManager.default.createFile(atPath:path!, contents: data, attributes: nil)
information.append(Information(image:path!, content:" ", url: " "))
saveDefaults()
tableView.reloadData()
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cellIdentifier = "TableViewCell"
/*Because you created a custom cell class that you want to use, downcast the type of the cell to your custom cell subclass, MealTableViewCell.*/
guard let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier , for: indexPath) as? TableViewCell
else{
fatalError("The dequeued cell is not an instance of MealTableViewCell.")
}
let info = information[indexPath.row]
if let data = FileManager.default.contents(atPath: info.image)
{
let decodeimage = UIImage(data: data)
cell.photos.image = decodeimage
}
else{
print("Not displaying image")
}
// cell.photos.image = UIImage(data: data!)
return cell
}
任何建议真的非常感谢。谢谢。
不要那样做。出于安全原因,文档文件夹的 URL 会定期更改。
保存相对路径(或仅保存文件名(,并在读取数据后获取当前文档 URL 并附加路径。
注意:NSSearchPathForDirectoriesInDomains
已过时。使用url(for:in:appropriateFor:create:)
和 FileManager
的 URL 相关 API
PS:为什么content
和url
是可选的,尽管字典初始值设定项始终传递非可选值?
这是工作代码。测试。 func getDocumentsURL(( -> URL {
let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
return documentsURL
}
func fileInDocumentsDirectory(filename: String) -> String {
let fileURL = getDocumentsURL().appendingPathComponent(filename)
return fileURL.path
}
并保存图像:
// Save image to Document directory
var imagePath = Date().description
imagePath = imagePath.replacingOccurrences(of: " ", with: "")
imagePath = "/(imagePath).png"
let relpath = getDocumentsURL()
let relativepath = relpath.appendingPathComponent(imagePath)
let data = UIImagePNGRepresentation(image)
let success = FileManager.default.createFile(atPath: relativepath.path , contents: data, attributes: nil)