ios – swift 2.0后的CGBitmapInfo alpha蒙版

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我使用这个 github repo https://github.com/Haneke/HanekeSwift中的一个库缓存从服务器下载的映像.更新到swift 2.0后,一切都搞砸了.

除了这个功能,我已经能够修复一切:

func hnk_decompressedImage() -> UIImage! {
    let originalImageRef = self.CGImage
    let originalBitmapInfo = CGImageGetBitmapInfo(originalImageRef)
    let alphaInfo = CGImageGetAlphaInfo(originalImageRef)

    // See: https://stackoverflow.com/questions/23723564/which-cgimagealphainfo-should-we-use
    var bitmapInfo = originalBitmapInfo
    switch (alphaInfo) {
    case .None:
        bitmapInfo &= ~CGBitmapInfo.AlphaInfoMask
        bitmapInfo |= CGBitmapInfo(rawValue: CGImageAlphaInfo.NoneSkipFirst.rawValue)
    case .PremultipliedFirst,.PremultipliedLast,.NoneSkipFirst,.NoneSkipLast:
        break
    case .Only,.Last,.First: // Unsupported
        return self
    }

    let colorSpace = CGColorSpaceCreateDeviceRGB()
    let pixelSize = CGSizeMake(self.size.width * self.scale,self.size.height * self.scale)
    if let context = CGBitmapContextCreate(nil,Int(ceil(pixelSize.width)),Int(ceil(pixelSize.height)),CGImageGetBitsPerComponent(originalImageRef),colorSpace,bitmapInfo) {

        let imageRect = CGRectMake(0,pixelSize.width,pixelSize.height)
        UIGraphicsPushContext(context)

        // Flip coordinate system. See: https://stackoverflow.com/questions/506622/cgcontextdrawimage-draws-image-upside-down-when-passed-uiimage-cgimage
        CGContextTranslateCTM(context,pixelSize.height)
        CGContextScaleCTM(context,1.0,-1.0)

        // UIImage and drawInRect takes into account image orientation,unlike CGContextDrawImage.
        self.drawInRect(imageRect)
        UIGraphicsPopContext()
        let decompressedImageRef = CGBitmapContextCreateImage(context)

        let scale = UIScreen.mainScreen().scale
        let image = UIImage(CGImage: decompressedImageRef,scale:scale,orientation:UIImageOrientation.Up)

        return image

    } else {
        return self
    }
}@H_404_5@ 
 

具体来说,这是抛出错误代码行:

bitmapInfo &= ~CGBitmapInfo.AlphaInfoMask
        bitmapInfo |= CGBitmapInfo(rawValue: CGImageAlphaInfo.NoneSkipFirst.rawValue)@H_404_5@ 
 

错误:一元运算符’〜’不能应用于CGBitmapInfo类型的操作数

bitmapInfo |= CGBitmapInfo(rawValue: CGImageAlphaInfo.NoneSkipFirst.rawValue)@H_404_5@ 
 

错误:二进制运算符’| =’不能应用于类型为’CGBitmapInfo’的操作数

if let context = CGBitmapContextCreate(nil,bitmapInfo)@H_404_5@ 
 

错误:无法将类型“CGBitmapInfo”的值转换为UInt32类型的预期参数

解决方法

错误:无法将类型“CGBitmapInfo”的值转换为UInt32类型的预期参数

Swift 2.0实际上期望一个UInt32而不是一个CGBitMapInfo对象,所以你应该在CGBitMapInfo中取出一个UInt32变量.

CGBitmapContextCreate(
    nil,bitmapInfo.rawValue)@H_404_5@ 
 

https://developer.apple.com/library/ios/documentation/GraphicsImaging/Reference/CGBitmapContext/#//apple_ref/c/func/CGBitmapContextCreate

原文链接:https://www.f2er.com/iOS/337108.html

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