swift CGImage怎么旋转

您可以使用以下代码旋转Swift中的CGImage：

func rotate(_ image: CGImage, angle: CGFloat) -> CGImage? {
    let imageWidth = image.width
    let imageHeight = image.height
    
    let bytesPerPixel = 4
    let bitsPerComponent = 8
    let bytesPerRow = bytesPerPixel * imageWidth
    
    let colorSpace = CGColorSpaceCreateDeviceRGB()
    
    let bitmapInfo = CGImageAlphaInfo.premultipliedLast.rawValue
    let context = CGContext(data: nil, width: imageWidth, height: imageHeight, bitsPerComponent: bitsPerComponent, bytesPerRow: bytesPerRow, space: colorSpace, bitmapInfo: bitmapInfo)!
    
    context.translateBy(x: CGFloat(imageWidth) / 2, y: CGFloat(imageHeight) / 2)
    context.rotate(by: angle)
    context.translateBy(x: -CGFloat(imageWidth) / 2, y: -CGFloat(imageHeight) / 2)
    
    context.draw(image, in: CGRect(x: 0, y: 0, width: imageWidth, height: imageHeight))
    
    return context.makeImage()
}

该函数将使用提供的角度旋转传递的图像。请注意，此功能将返回旋转后的图像的新CGImage。