有人知道如何将一个UIImage转换为Base64字符串,然后反转它吗?
我有以下代码;编码前的原始图像是好的,但编码解码后只得到一个空白图像。
NSData *imageData = UIImagePNGRepresentation(viewImage);
NSString *b64EncStr = [self encode: imageData];
NSString *base64String = [self encodeBase64:imageData];
有人知道如何将一个UIImage转换为Base64字符串,然后反转它吗?
我有以下代码;编码前的原始图像是好的,但编码解码后只得到一个空白图像。
NSData *imageData = UIImagePNGRepresentation(viewImage);
NSString *b64EncStr = [self encode: imageData];
NSString *base64String = [self encodeBase64:imageData];
当前回答
对于iOS 7+, Objective-C,下面是如何从一个图像URL开始转换:
NSURL *url = [NSURL URLWithString:self.groove.thumbnailURL];
UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:url]];
NSString *base64String = [UIImagePNGRepresentation(image)
base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
其他回答
很好理解你是否传递了Tyler Sheaffer所说的前缀。 但出于某种原因,你可能需要这个前缀来描述base64字符串开头的mime类型,所以我建议这段代码在编码之前传递一些选项(Swift 5):
extension UIImage {
enum Format: String {
case png = "png"
case jpeg = "jpeg"
}
func toBase64(type: Format = .jpeg, quality: CGFloat = 1, addMimePrefix: Bool = false) -> String? {
let imageData: Data?
switch type {
case .jpeg: imageData = jpegData(compressionQuality: quality)
case .png: imageData = pngData()
}
guard let data = imageData else { return nil }
let base64 = data.base64EncodedString(options: Data.Base64EncodingOptions.lineLength64Characters)
var result = base64
if addMimePrefix {
let prefix = "data:image/\(type.rawValue);base64,"
result = prefix + base64
}
return result
}
}
在Swift 3.0和Xcode 8.0
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
斯威夫特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
斯威夫特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
斯威夫特5号,Xcode 10号。
let imageData = UIImage(named:“imagename”).pngData()?.base64EncodedString(选项: .lineLength64Characters) 打印(图像数据)
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Swift5.0代码如下:
func imageFromBase64(_ base64: String) -> UIImage? {
if let url = URL(string: base64), let data = try? Data(contentsOf: url) {
return UIImage(data: data)
}
return nil
}