在UIImage和Base64字符串之间进行转换

Question

有人知道如何将 UIImage 转换为 Base64 字符串，然后再反转回来吗？

我有以下代码；编码前的原始图像很好，但编码和解码后我只得到了一张空白图像。

NSData *imageData = UIImagePNGRepresentation(viewImage);

NSString *b64EncStr = [self encode: imageData];

NSString *base64String = [self encodeBase64:imageData];

- changey

---

试试这个：https://github.com/l4u/NSData-Base64/ - user529758

有人能回答这个问题吗：http://stackoverflow.com/questions/39657434/issue-in-coverting-zlib-compressed-base-64-string-to-uiimage/39659390?noredirect=1#comment66621861_39659390 - user3011809

Answer 1

Swift

首先我们需要图像的NSData

//Use image name from bundle to create NSData
let image : UIImage = UIImage(named:"imageNameHere")!
//Now use image to create into NSData format
let imageData:NSData = UIImagePNGRepresentation(image)!

//OR next possibility

//Use image's path to create NSData
let url:NSURL = NSURL(string : "urlHere")!
//Now use image to create into NSData format
let imageData:NSData = NSData.init(contentsOfURL: url)!

Swift 2.0 > 编码

let strBase64:String = imageData.base64EncodedStringWithOptions(.Encoding64CharacterLineLength)

Swift 2.0 > 解码

let dataDecoded:NSData = NSData(base64EncodedString: strBase64, options: NSDataBase64DecodingOptions.IgnoreUnknownCharacters)!

Swift 3.0 > 解码

let dataDecoded : Data = Data(base64Encoded: strBase64, options: .ignoreUnknownCharacters)!

编码：

let strBase64 = imageData.base64EncodedString(options: .lineLength64Characters)
print(strBase64)

解码 :

let dataDecoded:NSData = NSData(base64EncodedString: strBase64, options: NSDataBase64DecodingOptions(rawValue: 0))!
let decodedimage:UIImage = UIImage(data: dataDecoded)!
print(decodedimage)
yourImageView.image = decodedimage

Swift 3.0

let dataDecoded : Data = Data(base64Encoded: strBase64, options: .ignoreUnknownCharacters)!
let decodedimage = UIImage(data: dataDecoded)
yourImageView.image = decodedimage

---

Objective-C

iOS7 > version

你可以使用NSData的base64EncodedStringWithOptions方法。

编码：

- (NSString *)encodeToBase64String:(UIImage *)image {
 return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
}

解码 :

- (UIImage *)decodeBase64ToImage:(NSString *)strEncodeData {
  NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters];
  return [UIImage imageWithData:data];
}

---

iOS 6.1及以下版本

第一选项：使用此链接对图像进行编码和解码

将Base64类添加到您的项目中。

编码：

 NSData* data = UIImageJPEGRepresentation(yourImage, 1.0f);
 NSString *strEncoded = [Base64 encode:data];

解码：

 NSData* data = [Base64 decode:strEncoded ];;
 image.image = [UIImage imageWithData:data];

另一种选择: 使用QSUtilities进行编码和解码

---

- Paresh Navadiya

---

Base64类会一直休眠，即使我将图像质量设置为0.001f后仍然如此。每次使用它时，我都不得不强制退出Xcode。 - shebelaw

现在在Swift中，您应该使用NSData(contentsOfURL: url, options: nil, error: nil)。 - quemeful

@Crashalot：已经做出了更改，请告知是否还有其他修改。 - Paresh Navadiya

重要说明：确保您的Base64字符串不包括浏览器显示所需的前缀，例如"data:image/jpeg;base64,"。 - Tyler Sheaffer

@TylerSheaffer 我认为这是一条重要的信息，应该包含在答案中。 - Timeless

Answer 2

Swift 5

编码

func convertImageToBase64String (img: UIImage) -> String {
    return img.jpegData(compressionQuality: 1)?.base64EncodedString() ?? ""
}

解码

func convertBase64StringToImage (imageBase64String:String) -> UIImage {
    let imageData = Data(base64Encoded: imageBase64String)
    let image = UIImage(data: imageData!)
    return image!
}

注意：在xcode 10.2中测试过

Swift 4

编码

func convertImageToBase64String (img: UIImage) -> String {
    let imageData:NSData = UIImageJPEGRepresentation(img, 0.50)! as NSData //UIImagePNGRepresentation(img)
    let imgString = imageData.base64EncodedString(options: .init(rawValue: 0))
    return imgString
}

解码

func convertBase64StringToImage (imageBase64String:String) -> UIImage {
    let imageData = Data.init(base64Encoded: imageBase64String, options: .init(rawValue: 0))
    let image = UIImage(data: imageData!)
    return image
}

注意：在xcode 9.4.1中测试过

- Vivek

---

谢谢您对我的回答进行评论，能否请您给我的回答点个赞呢？这对我来说非常有帮助。 - Vivek

Answer 3

Swift 4.2 扩展方法

extension UIImage {
    func toBase64() -> String? {
        guard let imageData = self.pngData() else { return nil }
        return imageData.base64EncodedString(options: .lineLength64Characters)
    }
}

XCode 9.1 和 Swift 4.0

//
// Convert UIImage to a base64 representation
//
class func convertImageToBase64(image: UIImage) -> String {
    let imageData = UIImagePNGRepresentation(image)!
    return imageData.base64EncodedString(options: Data.Base64EncodingOptions.lineLength64Characters)
}

//
// Convert a base64 representation to a UIImage
//
class func convertBase64ToImage(imageString: String) -> UIImage {
    let imageData = Data(base64Encoded: imageString, options: Data.Base64DecodingOptions.ignoreUnknownCharacters)!
    return UIImage(data: imageData)!
}

- Soufiane ROCHDI

---

这不好。如果从数据中获取图像失败，强制解包图像会导致应用程序崩溃。你应该像这样解包最后一行：“return UIImage(data: imageData) ?? UIImage()”。 - Vladimir Sukanica

强制解包不是一个好的做法，我建议：func convertBase64StringToImage(imageBase64String:String) -> UIImage? { guard let imageData = Data(base64Encoded: imageBase64String) else { return nil } let image = UIImage(data: imageData) return image } - Medhi

Answer 4

SWIFT 3.0，XCODE 8.0

用您的URL替换字符串，并将testImage设置为ImageView的出口。

// Put Your Image URL
let url:NSURL = NSURL(string : "http://.jpg")!
// It Will turn Into Data
let imageData : NSData = NSData.init(contentsOf: url as URL)!
// Data Will Encode into Base64
let str64 = imageData.base64EncodedData(options: .lineLength64Characters)
// Now Base64 will Decode Here
let data: NSData = NSData(base64Encoded: str64 , options: .ignoreUnknownCharacters)!
// turn  Decoded String into Data
let dataImage = UIImage(data: data as Data)
// pass the data image to image View.:)
testImage.image = dataImage

希望能够帮到您，谢谢。

- Avinash Mishra

Answer 5

快捷 iOS8

// prgm mark ---- 

// convert images into base64 and keep them into string

func convertImageToBase64(image: UIImage) -> String {

    var imageData = UIImagePNGRepresentation(image)
    let base64String = imageData.base64EncodedStringWithOptions(.allZeros)

    return base64String

}// end convertImageToBase64


// prgm mark ----

// convert images into base64 and keep them into string

func convertBase64ToImage(base64String: String) -> UIImage {

    let decodedData = NSData(base64EncodedString: base64String, options: NSDataBase64DecodingOptions(rawValue: 0) )

    var decodedimage = UIImage(data: decodedData!)

    return decodedimage!

}// end convertBase64ToImage

- Vinod Joshi

Answer 6

@implementation UIImage (Extended)

- (NSString *)base64String {
    NSData * data = [UIImagePNGRepresentation(self) base64EncodedDataWithOptions:NSDataBase64Encoding64CharacterLineLength];
    return [NSString stringWithUTF8String:[data bytes]];
}

@end

- Peter Lapisu

---

简单而优雅。喜欢它！ - Myxtic

Answer 7

Swift 3.0

将图片转换成base64字符串

在playground中测试通过

    var logo = UIImage(named: "image_logo")
    let imageData:Data =  UIImagePNGRepresentation(logo)
    let base64String = imageData.base64EncodedString()
    print(base64String)

- dimohamdy

Answer 8

在Swift 2.0中，使用以下扩展（鸣谢Jonas Franz）：

extension UIImage{
  func toBase64() -> String{
    let imageData = UIImagePNGRepresentation(self)!
    return imageData.base64EncodedStringWithOptions(.Encoding64CharacterLineLength)
  }
}

- Ciprian Rarau

Answer 9

对于 Base64 代码，例如:

"data:image/jpg;base64,iVBORw0KGgoAAAANSUhEUgAAAMgAAADIAQAAAACFI5MzAAAB9klEQVR42u2YQYorMQxEBbqWQFc36FoG/6pyOpNZ/J20mGGaTiftF2hbLpWU2PnfYX/k55Jl5vhUVTu8luUdaCeFcydejjdwDUyQ5XV2JOcSZnkHZgiejusK51QGycrl2yIR1BwjjKivSFz8YC7fY91GKIj6PL5pp4/wWL54t3MHt/AjFxoJwmkYwosbh6/UEHE817hvi/vGex8gEkTdVRo1/55BM7kjUIgpoMW1DxB6kD+GtCX4PUFws40OwcUm0/lRYjOB3pG9YcguBFQuO0ISJ9UIrUP5CKy/MriXHDkETYmLDax1+RkgWBglQgUyq6T/HCAHBq7iJHd9KWWAlIKoGpiLc6HNDhDkETNYwqeVhym72snKKxA6BJL4UPM5QPYtgGwZeNZ5O0UvgSb0VGdcmVfJCQwQrM+pRiGnYJ497SUlv2NOYfOCX3qU2Equ7W3JAslsN7oDBDWWojcZq+KbEwQRdRYl1wD3ML52rpGc6w24qCXaKh4DRHWJbUPemqtEGyBMKC4Q/QmWiDWzRxkgO1UtSLh3svMaILeDpEGwrwvZ4Bkg9LynK1Y1LJWQdqKGnm3K7VTCz7vS9hIuUyYRd/xKcYRIHGqAViisQ4S/Uozmqo41Pn6bNRI1xS/fk2fMEKpDZYkpjP6B1T0HyN9/Nb+M/AORXDdE4Lb/mQAAAABJRU5ErkJggg=="

使用 Swift 5.0 代码:

func imageFromBase64(_ base64: String) -> UIImage? {
    if let url = URL(string: base64), let data = try? Data(contentsOf: url) {
        return UIImage(data: data)
    }
    return nil
}

- Yun CHEN

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有人可以指出这种行为在哪里有文档记录吗？ - Leo Dabus

这不正确。https://stackoverflow.com/a/51394491/1294452 或 https://stackoverflow.com/a/47610733/1294452 下面 - undefined

@nodebase 这个解决方案对我来说是有效的。为什么这不正确呢？你能提供更多的上下文吗？我需要转换类型为 "data:image/jpg;base64,iV... 的图像。而且以下任何解决方案都无法适用于这种情况。 - undefined

Answer 10

在Swift 3.0和Xcode 8.0中，编码是一个重要的概念。

编码：

let userImage:UIImage = UIImage(named: "Your-Image_name")!
let imageData:NSData = UIImagePNGRepresentation(userImage)! as NSData
let dataImage = imageData.base64EncodedString(options: .lineLength64Characters)

解码：

let imageData = dataImage
let dataDecode:NSData = NSData(base64Encoded: imageData!, options:.ignoreUnknownCharacters)!
let avatarImage:UIImage = UIImage(data: dataDecode as Data)!
yourImageView.image = avatarImage

- M.Nadeeshan