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];
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];
Swift 4
enum ImageFormat {
case png
case jpeg(CGFloat)
}
extension UIImage {
func base64(format: ImageFormat) -> String? {
var imageData: Data?
switch format {
case .png: imageData = UIImagePNGRepresentation(self)
case .jpeg(let compression): imageData = UIImageJPEGRepresentation(self, compression)
}
return imageData?.base64EncodedString()
}
}
extension String {
func imageFromBase64() -> UIImage? {
guard let data = Data(base64Encoded: self) else { return nil }
return UIImage(data: data)
}
}
Swift扩展:
extension UIImage{
func toBase64() -> String{
var imageData = UIImagePNGRepresentation(self)
return imageData.base64EncodedStringWithOptions(.allZeros)
}
}
let imageData = UIImagePNGRepresentation(ImageView.image!); let strBase64:String = imageData!.base64EncodedString()
- CmagSwift 5.
class ImageConverter {
func base64ToImage(_ base64String: String) -> UIImage? {
guard let imageData = Data(base64Encoded: base64String) else { return nil }
return UIImage(data: imageData)
}
func imageToBase64(_ image: UIImage) -> String? {
return image.jpegData(compressionQuality: 1)?.base64EncodedString()
}
}
我尝试了所有的解决方案,但都没有成功(使用Swift 4),这是对我有用的解决方案,如果将来有人遇到同样的问题。
let temp = base64String.components(separatedBy: ",")
let dataDecoded : Data = Data(base64Encoded: temp[1], options:
.ignoreUnknownCharacters)!
let decodedimage = UIImage(data: dataDecoded)
yourImage.image = decodedimage
了解 Tyler Sheaffer 所说的前缀非常重要。 但是由于某些原因,您可能需要在 base64 字符串的开头添加描述 mime-type 的前缀,因此我建议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
}
}
Swift版本 - 为图像创建base64
在我的看法中,在UIImagePNGRepresentation()
中使用隐式解包可选项是不安全的,所以我建议使用以下扩展:
extension UIImage {
func toBase64() -> String? {
let imageData = UIImagePNGRepresentation(self)
return imageData?.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.Encoding64CharacterLineLength)
}
}
使用方便的初始化器解码 - Swift 5
extension UIImage {
convenience init?(base64String: String) {
guard let data = Data(base64Encoded: base64String) else { return nil }
self.init(data: data)
}
}
See my class - AppExtension.swift
// MARK: - UIImage (Base64 Encoding)
public enum ImageFormat {
case PNG
case JPEG(CGFloat)
}
extension UIImage {
public func base64(format: ImageFormat) -> String {
var imageData: NSData
switch format {
case .PNG: imageData = UIImagePNGRepresentation(self)
case .JPEG(let compression): imageData = UIImageJPEGRepresentation(self, compression)
}
return imageData.base64EncodedStringWithOptions(.allZeros)
}
}
Swift 4.2 | Xcode 10
extension UIImage {
/// EZSE: Returns base64 string
public var base64: String {
return self.jpegData(compressionQuality: 1.0)!.base64EncodedString()
}
}
func decodeBase64(toImage strEncodeData: String) -> UIImage {
let dataDecoded = NSData(base64Encoded: strEncodeData, options: NSData.Base64DecodingOptions.ignoreUnknownCharacters)!
let image = UIImage(data: dataDecoded as Data)
return image!
}