通过 NSData 将 UIImage 转换为 NSSString 时出错

Question

我正在尝试将我的 UIImage 从 UIImageView 转换为字符串，因为数据存储为 Base64。我正在使用下面的方法来转换图像，但在尝试更新 convertedStr 时它会失败。

func convertImg() {
    let imageData: NSData = UIImagePNGRepresentation(imageView.image!)! as NSData
    convertedStr = NSString(data: imageData as Data, encoding: String.Encoding.utf8.rawValue)!
}

这个函数是关于版本 10 的，因为我尝试了不同的方法，但结果总是一样的。返回的错误是

'fatal error: unexpectedly found nil while unwrapping an Optional value' and

'function signature specialization ) -> () to @callee_owned (@unowned Swift.UnsafeBufferPointer) -> (@out ()), Argument Types : [@callee_owned (@unowned Swift.UnsafeBufferPointer) -> ()]> of generic specialization of Swift.StaticString.withUTF8Buffer ((Swift.UnsafeBufferPointer) -> A) -> A'

会不会是我使用的方法需要一个 png 文件并且不适用于 UIImage？

Answer 1

func convertImg() {
    let imageData: NSData = UIImagePNGRepresentation(imageView.image!)! as NSData
    convertstr = imageData.base64EncodedString(options: lineLength64Characters)

}

Answer 2

在Swift

编码为 swift 2.0 及更低版本

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

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

解码

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

通过 NSData 将 UIImage 转换为 NSSString 时出错

Getting an error when converting UIImage to NSSString via NSData

nsdate

ios

uiimagepngrepresentation

swift