如何从本地路径 ios swift 加载图像（按路径）答案

【问题标题】：how to load image from local path ios swift (by path)如何从本地路径 ios swift 加载图像（按路径）
【发布时间】：2016-10-01 04:15:22
【问题描述】：

在我的应用程序中，我将图像存储在本地存储中，并将该图像的路径保存在我的数据库中。如何从该路径加载图像？

这是我用来保存图像的代码：

 let myimage : UIImage = UIImage(data: data)!
            let fileManager = NSFileManager.defaultManager()
            let urls = fileManager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
            let documentDirectory = urls[0] as NSURL


            print(documentDirectory)
            let currentDate = NSDate()

            let dateFormatter = NSDateFormatter()
            dateFormatter.dateStyle = .NoStyle
            dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
            let convertedDate = dateFormatter.stringFromDate(currentDate)
            let imageURL = documentDirectory.URLByAppendingPathComponent(convertedDate)
            imageUrlPath  = imageURL.absoluteString
            print(imageUrlPath)
            UIImageJPEGRepresentation(myimage,1.0)!.writeToFile(imageUrlPath, atomically: true)

这是我的图像存储的路径

file:///var/mobile/Containers/Data/Application/B2A1EE50-D800-4BB0-B475-6C7F210C913C/Documents/2016-06-01%2021:49:32

这就是我尝试检索图像的方式，但它没有显示任何内容。

let image : String = person?.valueForKey("image_local_path") as! String
        print(person!.valueForKey("image_local_path")! as! String)
        cell.img_message_music.image = UIImage(contentsOfFile: image)

【问题讨论】：

这一行：imageUrlPath = imageURL.absoluteString 需要是imageUrlPath = imageURL.path
顺便说一句，你不应该把data转换成UIImage，然后再用UIImageJPEGRepresentation转换回NSData。只需保存原始的data。
UIImage(contentsOfFile:) returning nil despite file existing in caches directory的可能重复
我处于相同的场景中，请注意，每次运行/构建/更新应用程序时，您的 B2A1EE50xx 文件夹都会更改，如下面的@zsyesenko 所述。所以你需要写imageUrl而不是imageUrlPath并保存你的文件名（convertedDate在你的情况下）不是路径

标签： ios swift image nsdocumentdirectory

【解决方案1】：

将absoluteString 替换为path

let myimage : UIImage = UIImage(data: data)!
        let fileManager = NSFileManager.defaultManager()
        let urls = fileManager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
        let documentDirectory = urls[0] as NSURL


        print(documentDirectory)
        let currentDate = NSDate()

        let dateFormatter = NSDateFormatter()
        dateFormatter.dateStyle = .NoStyle
        dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
        let convertedDate = dateFormatter.stringFromDate(currentDate)
        let imageURL = documentDirectory.URLByAppendingPathComponent(convertedDate)
        imageUrlPath  = imageURL.path
        print(imageUrlPath)
        UIImageJPEGRepresentation(myimage,1.0)!.writeToFile(imageUrlPath, atomically: true)

【讨论】：

【解决方案2】：

你也可以试试这个。

检查你的路径是否存在

if NSFileManager.defaultManager().fileExistsAtPath(imageUrlPath) {}

为您的路径创建一个 URL

let url = NSURL(string: imageUrlPath)

为您的 URL 创建数据

let data = NSData(contentsOfURL: url!)

将 url 绑定到您的 imageView

imageView.image = UIImage(data: data!)

最终代码：

if NSFileManager.defaultManager().fileExistsAtPath(imageUrlPath) {
    let url = NSURL(string: imageUrlPath)
    let data = NSData(contentsOfURL: url!)
    imageView.image = UIImage(data: data!)
}

【讨论】：

【解决方案3】：

文件夹 /B2A1EE50- ... 每次运行应用程序时都会更改。

../Application/B2A1EE50-D800-4BB0-B475-6C7F210C913C/Documents/..

对我有用的是存储文件名并获取文档文件夹。

斯威夫特 5

为目录文件夹创建getter

var documentsUrl: URL {
    return FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
}

保存图片：

private func save(image: UIImage) -> String? {
    let fileName = "FileName"
    let fileURL = documentsUrl.appendingPathComponent(fileName)
    if let imageData = image.jpegData(compressionQuality: 1.0) {
       try? imageData.write(to: fileURL, options: .atomic)
       return fileName // ----> Save fileName
    }
    print("Error saving image")
    return nil
}

加载图片：

private func load(fileName: String) -> UIImage? {
    let fileURL = documentsUrl.appendingPathComponent(fileName)
    do {
        let imageData = try Data(contentsOf: fileURL)
        return UIImage(data: imageData)
    } catch {
        print("Error loading image : \(error)")
    }
    return nil
}

【讨论】：

【解决方案4】：

此示例代码可能会节省一些人的打字时间，

在您自己的目录中将 UIImage 写入磁盘：

IM = UIImage, your image. for example, IM = someUIView.image or from the camera

let newPhotoFileName = randomNameString() + ".jpeg"
let imagePath = checkedImageDirectoryStringPath() + "/" + newPhotoFileName

let imData = UIImageJPEGRepresentation(IM, 0.20)
FileManager.default.createFile(atPath: imagePath, contents: imData, attributes: nil)

print("saved at filename \(newPhotoFileName)")

稍后阅读该图像...

.. 并将其转换回 UIImage，就像在 UIImageView 中一样

NAME = that filename, like jahgfdfs.jpg

let p = checkedImageDirectoryStringPath() + "/" + NAME
devCheckExists(fullPath: p)

var imageData: Data? = nil
do {
    let u = URL(fileURLWithPath: p)
    imageData = try Data(contentsOf: u)
}
catch {
    print("catastrophe loading file?? \(error)")
    return
}

// and then to "make that an image again"...

imageData != nil {

    picture.image = UIImage(data: imageData!)
    print("that seemed to work")
}
else {

    print("the imageData is nil?")
}

// or for example...

Alamofire.upload(
    multipartFormData: { (multipartFormData) in
        multipartFormData.append(imageData!,
           withName: "file", fileName: "", mimeType: "image/jpeg")
    ...

这里是上面用到的非常方便的函数...

func checkedImageDirectoryStringPath()->String {

    // create/check OUR OWN IMAGE DIRECTORY for use of this app.

    let paths = NSSearchPathForDirectoriesInDomains(
                      .documentDirectory, .userDomainMask, true)

    if paths.count < 1 {
        print("some sort of disaster finding the our Image Directory - giving up")
        return "x"
        // any return will lead to disaster, so just do that
        // (it will then gracefully fail when you "try" to write etc)
    }

    let docDirPath: String = paths.first!
    let ourDirectoryPath = docDirPath.appending("/YourCompanyName")
    // so simply makes a directory called "YourCompanyName"
    // which will be there for all time, for your use

    var ocb: ObjCBool = true
    let exists = FileManager.default.fileExists(
                  atPath: ourDirectoryPath, isDirectory: &ocb)

    if !exists {
        do {
            try FileManager.default.createDirectory(
                    atPath: ourDirectoryPath,
                    withIntermediateDirectories: false,
                    attributes: nil)

            print("we did create our Image Directory, for the first time.")
            // never need to again
            return ourDirectoryPath
        }
        catch {
            print(error.localizedDescription)
            print("disaster trying to make our Image Directory?")
            return "x"
            // any return will lead to disaster, so just do that
        }
    }

    else {

        // already exists, as usual.
        return ourDirectoryPath
    }
}

和

func randomNameString(length: Int = 7)->String{

    enum s {
        static let c = Array("abcdefghjklmnpqrstuvwxyz12345789".characters)
        static let k = UInt32(c.count)
    }

    var result = [Character](repeating: "a", count: length)

    for i in 0..<length {
        let r = Int(arc4random_uniform(s.k))
        result[i] = s.c[r]
    }

    return String(result)
}

和

func devCheckExists(fullPath: String) {

    var ocb: ObjCBool = false
    let itExists = FileManager.default.fileExists(atPath: fullPath, isDirectory: &ocb)
    if !itExists {
        // alert developer. processes will fail at next step
        print("\n\nDOES NOT EXIST\n\(fullPath)\n\n")
    }
}

【讨论】：

【解决方案5】：

此代码适用于我

func getImageFromDir(_ imageName: String) -> UIImage? {

    if let documentsUrl = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first {
        let fileURL = documentsUrl.appendingPathComponent(imageName)
        do {
            let imageData = try Data(contentsOf: fileURL)
            return UIImage(data: imageData)
        } catch {
            print("Not able to load image")
        }
    }
    return nil
}

【讨论】：

【解决方案6】：

1.cell.image.sd_setShowActivityIndicatorView(true)

2.cell.image.sd_setIndicatorStyle(.gray)

3.cell.image.image = UIImage(contentsOfFile: urlString!)

【讨论】：

不要将不是图像的东西命名为“图像”。在您的示例中，您最终会得到荒谬的命名，例如“image.image”。
你跑题了，伙计：-/

【解决方案7】：

斯威夫特 4：

if FileManager.default.fileExists(atPath: imageUrlPath) {
            let url = NSURL(string: imageUrlPath)
            let data = NSData(contentsOf: url! as URL)

            chapterImage.image = UIImage(data: data! as Data)
        }

【讨论】：

【解决方案8】：

这对我有用，我认为这是一种快速而干净的方式。

Swift 5.0

let fileManager = NSFileManager.defaultManager()
let urls = fileManager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
let documentDirectory = urls[0] as NSURL

print(documentDirectory)
let currentDate = NSDate()

let dateFormatter = NSDateFormatter()
dateFormatter.dateStyle = .NoStyle
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
let convertedDate = dateFormatter.stringFromDate(currentDate)
let imageURL = documentDirectory.URLByAppendingPathComponent(convertedDate)
let imageData = try? Data(contentsOf: imageUrl)
let image = UIImage(data: imageData!)

其中“imageUrl”是文档文件夹中 imageURL 的值。 “图像”是您可以在任何需要的地方使用的结果图像。

【讨论】：