ALAsset中获取照片的原图并转换成NSData,UIImage

iOS

way1:

if let mCGImageVal = mALAsset?.defaultRepresentation().fullScreenImage().takeUnretainedValue() {
    self?.imageView.image = UIImage(cgImage: mCGImageVal)
}

way2:

http://www.hangge.com/blog/cache/detail_759.html

if let representation =  myALAsset.defaultRepresentation() {
let representationSize =Int(representation.size()) 
let imageBuffer = UnsafeMutablePointer<UInt8>.allocate(capacity: representationSize)
let bufferSize = representation.getBytes(imageBuffer, fromOffset: Int64(0),                                                   length: Int(representation.size()), error: nil)

let imgData:NSData =  NSData(bytesNoCopy:imageBuffer     ,length:bufferSize, freeWhenDone:true)
self?.imageView.image = UIImage(data: imgData as Data)

}