保存图像并将其加载到Swift (iOS)
保存图像并将其加载到Swift (iOS)
提问于 2016-05-20 18:52:45
我正在使用saveImage保存图像。
func saveImage (image: UIImage, path: String ) -> Bool{
let pngImageData = UIImagePNGRepresentation(image)
//let jpgImageData = UIImageJPEGRepresentation(image, 1.0) // if you want to save as JPEG
print("!!!saving image at: \(path)")
let result = pngImageData!.writeToFile(path, atomically: true)
return result
}新信息：
保存文件不能正常工作(打印“- ERROR Saving FILE”)--
// save your image here into Document Directory
let res = saveImage(tempImage, path: fileInDocumentsDirectory("abc.png"))
if(res == true){
print ("[+] FILE SAVED")
}else{
print ("[-] ERROR SAVING FILE")
}为什么saveImage函数不保存图像？访问权限？
旧信息：
调试信息显示：
!!!saving image at: file:///var/mobile/Applications/BDB992FB-E378-4719-B7B7-E9A364EEE54B/Documents/tempImage然后，我使用以下命令检索此位置
fileInDocumentsDirectory("tempImage")结果是正确的。
然后，我将使用以下路径加载文件
let image = UIImage(contentsOfFile: path)
if image == nil {
print("missing image at: \(path)")
}else{
print("!!!IMAGE FOUND at: \(path)")
}路径正确，但消息是"missing image at..“。文件是因为某种原因无法访问还是没有存储？导致这种行为的原因可能是什么？
我正在iOS7的iPhone4和iOS7模拟器的iPhone5上测试这段代码。
编辑: 1. fileInDocumentsDirectory函数
func fileInDocumentsDirectory(filename: String) -> String {
let documentsURL = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0]
let fileURL = documentsURL.URLByAppendingPathComponent(filename).absoluteString
return fileURL
}回答 11
Stack Overflow用户
发布于 2017-06-04 21:50:39
此函数将在documents文件夹中保存图像：
func saveImage(image: UIImage) -> Bool {
guard let data = UIImageJPEGRepresentation(image, 1) ?? UIImagePNGRepresentation(image) else {
return false
}
guard let directory = try? FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false) as NSURL else {
return false
}
do {
try data.write(to: directory.appendingPathComponent("fileName.png")!)
return true
} catch {
print(error.localizedDescription)
return false
}
}要使用以下命令：
let success = saveImage(image: UIImage(named: "image.png")!)此函数将获取该图像：
func getSavedImage(named: String) -> UIImage? {
if let dir = try? FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false) {
return UIImage(contentsOfFile: URL(fileURLWithPath: dir.absoluteString).appendingPathComponent(named).path)
}
return nil
}要使用以下命令：
if let image = getSavedImage(named: "fileName") {
// do something with image
}Stack Overflow用户
发布于 2018-12-22 17:19:16
iOS 13+ Swift 5.1
iOS 12引入了一些API更改。
func saveImage(imageName: String, image: UIImage) {
guard let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else { return }
let fileName = imageName
let fileURL = documentsDirectory.appendingPathComponent(fileName)
guard let data = image.jpegData(compressionQuality: 1) else { return }
//Checks if file exists, removes it if so.
if FileManager.default.fileExists(atPath: fileURL.path) {
do {
try FileManager.default.removeItem(atPath: fileURL.path)
print("Removed old image")
} catch let removeError {
print("couldn't remove file at path", removeError)
}
}
do {
try data.write(to: fileURL)
} catch let error {
print("error saving file with error", error)
}
}
func loadImageFromDiskWith(fileName: String) -> UIImage? {
let documentDirectory = FileManager.SearchPathDirectory.documentDirectory
let userDomainMask = FileManager.SearchPathDomainMask.userDomainMask
let paths = NSSearchPathForDirectoriesInDomains(documentDirectory, userDomainMask, true)
if let dirPath = paths.first {
let imageUrl = URL(fileURLWithPath: dirPath).appendingPathComponent(fileName)
let image = UIImage(contentsOfFile: imageUrl.path)
return image
}
return nil
}Stack Overflow用户
发布于 2019-04-27 05:15:03
详细信息
- Xcode版本10.2 (10E125)，Swift 5
解决方案
// save
extension UIImage {
func save(at directory: FileManager.SearchPathDirectory,
pathAndImageName: String,
createSubdirectoriesIfNeed: Bool = true,
compressionQuality: CGFloat = 1.0) -> URL? {
do {
let documentsDirectory = try FileManager.default.url(for: directory, in: .userDomainMask,
appropriateFor: nil,
create: false)
return save(at: documentsDirectory.appendingPathComponent(pathAndImageName),
createSubdirectoriesIfNeed: createSubdirectoriesIfNeed,
compressionQuality: compressionQuality)
} catch {
print("-- Error: \(error)")
return nil
}
}
func save(at url: URL,
createSubdirectoriesIfNeed: Bool = true,
compressionQuality: CGFloat = 1.0) -> URL? {
do {
if createSubdirectoriesIfNeed {
try FileManager.default.createDirectory(at: url.deletingLastPathComponent(),
withIntermediateDirectories: true,
attributes: nil)
}
guard let data = jpegData(compressionQuality: compressionQuality) else { return nil }
try data.write(to: url)
return url
} catch {
print("-- Error: \(error)")
return nil
}
}
}
// load from path
extension UIImage {
convenience init?(fileURLWithPath url: URL, scale: CGFloat = 1.0) {
do {
let data = try Data(contentsOf: url)
self.init(data: data, scale: scale)
} catch {
print("-- Error: \(error)")
return nil
}
}
}用法
// save image (way 1)
let path = "photo/temp/album1/img.jpg"
guard let img = UIImage(named: "img"),
let url = img.save(at: .documentDirectory,
pathAndImageName: path) else { return }
print(url)
// get image from directory
guard let img2 = UIImage(fileURLWithPath: url) else { return }
// save image (way 2)
let tempDirectoryUrl = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(path)
guard let url2 = img2.save(at: tempDirectoryUrl) else { return }
print(url2)检查结果
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/37344822
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