When we get a screenshot of a UIView, we use this code usually:
UIGraphicsBeginImageContextWithOptions(frame.size, false, scale)
drawViewHierarchyInRect(bounds, afterScreenUpdates: true)
var image:UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
drawViewHierarchyInRect
&& UIGraphicsGetImageFromCurrentImageContext
will generate an image in current Context,but Memory will not released when when called UIGraphicsEndImageContext
.
Memory using continues to increase until the app crashes.
Although there is a word UIGraphicsEndImageContext
will call CGContextRelease
automatically",it doesn't work.
How can I release the memory drawViewHierarchyInRect
or UIGraphicsGetImageFromCurrentImageContext
used
Is there anyway generating screenshot without drawViewHierarchyInRect
?
1 Auto release : not work
var image:UIImage?
autoreleasepool{
UIGraphicsBeginImageContextWithOptions(frame.size, false, scale)
drawViewHierarchyInRect(bounds, afterScreenUpdates: true)
image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
}
image = nil
2 UnsafeMutablePointer : not work
var image:UnsafeMutablePointer<UIImage> = UnsafeMutablePointer.alloc(1)
autoreleasepool{
UIGraphicsBeginImageContextWithOptions(frame.size, false, scale)
drawViewHierarchyInRect(bounds, afterScreenUpdates: true)
image.initialize(UIGraphicsGetImageFromCurrentImageContext())
UIGraphicsEndImageContext()
}
image.destroy()
image.delloc(1)
I solved this problem by putting image operations in another queue!
private func processImage(image: UIImage, size: CGSize, completion: (image: UIImage) -> Void) {
dispatch_async(dispatch_get_global_queue(Int(QOS_CLASS_USER_INITIATED.rawValue), 0)) {
UIGraphicsBeginImageContextWithOptions(size, true, 0)
image.drawInRect(CGRect(origin: CGPoint.zero, size: size))
let tempImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
completion(image: tempImage)
}
}