UIImageView contentMode 在应用模糊效果后不起作用

Question

我正在尝试将 UIImageView 的图像属性设置为我用 CoreImage 模糊的图像。该代码与未过滤的图像完美配合，但是当我将背景图像设置为过滤后的图像时，contentMode 似乎停止为 UIImageView 工作——而不是纵横比填充，图像变得垂直拉伸。我除了在代码里设置了contentMode，在storyboard上也设置了，结果都是一样的

我正在使用 Swift 2 / Xcode 7.

func updateBackgroundImage(image: UIImage) {
    backgroundImage.contentMode = .ScaleAspectFill
    backgroundImage.layer.masksToBounds = true
    backgroundImage.image = blurImage(image)
}

func blurImage(image: UIImage) -> UIImage {
    let imageToBlur = CIImage(image: image)!

    let blurfilter = CIFilter(name: "CIGaussianBlur")!
    blurfilter.setValue(10, forKey: kCIInputRadiusKey)
    blurfilter.setValue(imageToBlur, forKey: "inputImage")

    let resultImage = blurfilter.valueForKey("outputImage") as! CIImage
    let croppedImage: CIImage = resultImage.imageByCroppingToRect(CGRectMake(0, 0, imageToBlur.extent.size.width, imageToBlur.extent.size.height))
    let blurredImage = UIImage(CIImage: croppedImage)

    return blurredImage
}

为什么使用 CIImage 过滤会导致我的图像被忽略 contentMode，我该如何解决这个问题？

Answer 1

解决办法是更换你的线路：

let blurredImage = UIImage(CIImage: croppedImage)

使用这两行：

let context = CIContext(options: nil)
let blurredImage = UIImage (CGImage: context.createCGImage(croppedImage, fromRect: croppedImage.extent))

因此您的完整 blurImage 函数将如下所示：

func blurImage(image: UIImage) -> UIImage {
    let imageToBlur = CIImage(image: image)!

    let blurfilter = CIFilter(name: "CIGaussianBlur")!
    blurfilter.setValue(10, forKey: kCIInputRadiusKey)
    blurfilter.setValue(imageToBlur, forKey: "inputImage")

    let resultImage = blurfilter.valueForKey("outputImage") as! CIImage
    let croppedImage: CIImage = resultImage.imageByCroppingToRect(CGRectMake(0, 0, imageToBlur.extent.size.width, imageToBlur.extent.size.height))
    let context = CIContext(options: nil)
    let blurredImage = UIImage (CGImage: context.createCGImage(croppedImage, fromRect: croppedImage.extent))

    return blurredImage
}

UIImageView contentMode 在应用模糊效果后不起作用

UIImageView contentMode not working after blur effect application

uiimageview

uiimage

ios

ciimage

swift