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Base64代码,例如:
"data:image/jpg;base64,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"
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
}
其他回答
斯威夫特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()
}
}
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)
}
}
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];
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)!
}
在swift 2.0中使用此扩展(credit to Jonas Franz)
extension UIImage{
func toBase64() -> String{
let imageData = UIImagePNGRepresentation(self)!
return imageData.base64EncodedStringWithOptions(.Encoding64CharacterLineLength)
}
}