PHAsset到UIImage

Question

我正在尝试从一个UIImage创建一个PHAsset (比如缩略图或其他东西)，这样我就可以将它传递到需要UIImage的东西中。我尝试过调整我在SO上找到的解决方案(因为它们都只是直接传递给表视图之类的)，但我没有成功(可能是因为我做得不对)。

func getAssetThumbnail(asset: PHAsset) -> UIImage {
    var retimage = UIImage()
    println(retimage)
    let manager = PHImageManager.defaultManager()
    manager.requestImageForAsset(asset, targetSize: CGSize(width: 100.0, height: 100.0), contentMode: .AspectFit, options: nil, resultHandler: {(result, info)->Void in
            retimage = result
    })
    println(retimage)
    return retimage
}

printlns告诉我，manager.request行现在没有做任何事情。我如何让它给我资产作为一个UIImage。

谢谢。

Answer 1

这做了我想做的事，以防有人也需要这个。

func getAssetThumbnail(asset: PHAsset) -> UIImage {
    let manager = PHImageManager.defaultManager()
    let option = PHImageRequestOptions()
    var thumbnail = UIImage()
    option.synchronous = true
    manager.requestImageForAsset(asset, targetSize: CGSize(width: 100.0, height: 100.0), contentMode: .AspectFit, options: option, resultHandler: {(result, info)->Void in
            thumbnail = result!
    })
    return thumbnail
}

编辑: Swift 3更新

func getAssetThumbnail(asset: PHAsset) -> UIImage {
    let manager = PHImageManager.default()
    let option = PHImageRequestOptions()
    var thumbnail = UIImage()
    option.isSynchronous = true
    manager.requestImage(for: asset, targetSize: CGSize(width: 100, height: 100), contentMode: .aspectFit, options: option, resultHandler: {(result, info)->Void in
        thumbnail = result!
    })
    return thumbnail
}

Answer 2

试试它对我有用，希望它也能帮到你，

func getUIImage(asset: PHAsset) -> UIImage? {

    var img: UIImage?
    let manager = PHImageManager.default()
    let options = PHImageRequestOptions()
    options.version = .original
    options.isSynchronous = true
    manager.requestImageData(for: asset, options: options) { data, _, _, _ in

        if let data = data {
            img = UIImage(data: data)
        }
    }
    return img
}

Answer 3

简单解决方案(SWIFT4.2)

方法1:

extension PHAsset {

    var image : UIImage {
        var thumbnail = UIImage()
        let imageManager = PHCachingImageManager()
        imageManager.requestImage(for: self, targetSize: CGSize(width: 100, height: 100), contentMode: .aspectFit, options: nil, resultHandler: { image, _ in
            thumbnail = image!
        })
        return thumbnail
    }
}                          

let image = asset.image 

如果您只需要使用来自UIImage的PHAsset，则使用此方法。

或

extension PHAsset {
    func image(targetSize: CGSize, contentMode: PHImageContentMode, options: PHImageRequestOptions?) -> UIImage {
        var thumbnail = UIImage()
        let imageManager = PHCachingImageManager()
        imageManager.requestImage(for: self, targetSize: targetSize, contentMode: contentMode, options: options, resultHandler: { image, _ in
            thumbnail = image!
        })
        return thumbnail
    }
}

let image = asset.image(targetSize: CGSize, contentMode: PHImageContentMode, options: PHImageRequestOptions?)

将此方法用于所需的UIImage。

或

extension PHAsset {

    func image(completionHandler: @escaping (UIImage) -> ()){
        var thumbnail = UIImage()
        let imageManager = PHCachingImageManager()
        imageManager.requestImage(for: self, targetSize: CGSize(width: 100, height: 100), contentMode: .aspectFit, options: nil, resultHandler: { img, _ in
            thumbnail = img!
        })
        completionHandler(thumbnail)
    }
}

let image = asset.image(completionHandler: {(img) in
    print("Finished")
})

使用此方法在完成后通知。

方法2:

extension PHAsset {
    var data : (UIImage, [AnyHashable : Any]) {
        var img = UIImage(); var information = [AnyHashable : Any](); let imageManager = PHCachingImageManager()
        imageManager.requestImage(for: self, targetSize: CGSize(width: 100, height: 100), contentMode: .aspectFit, options: nil, resultHandler: { image,info in
            img = image!
            information = info!
        })
        return (img,information)
    }
} 


let image_withData : (UIImage, [AnyHashable : Any]) = asset.data

如果要使用UIImage和PHAsset的结果信息，请使用此方法

或

extension PHAsset {

    func data(targetSize: CGSize, contentMode: PHImageContentMode, options: PHImageRequestOptions?) -> (UIImage, [AnyHashable : Any]) {
        var img = UIImage(); var information = [AnyHashable : Any](); let imageManager = PHCachingImageManager()
        imageManager.requestImage(for: self, targetSize: targetSize, contentMode: contentMode, options: options, resultHandler: { image,info in
            img = image!
            information = info!
        })
        return (img,information)
    }
}

let data = asset?.data(targetSize: CGSize, contentMode: PHImageContentMode, options: PHImageRequestOptions?)

对所需数据使用此方法。