Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0 - swift

Question

I am using below code in my project. After update to swift 4 and run my app crashed . How can I fix it?
Code:
func from(systemItem: UIBarButtonSystemItem)-> UIImage? {
let tempItem = UIBarButtonItem(barButtonSystemItem: systemItem, target: nil, action: nil)
// add to toolbar and render it
UIToolbar().setItems([tempItem], animated: false)
// got image from real uibutton
let itemView = tempItem.value(forKey: "view") as! UIView
for view in itemView.subviews {
if let button = view as? UIButton, let imageView = button.imageView {
return imageView.image
}
}
return nil
}
}
extension UITextView {
static let ScrollModeBottom = "UITextFieldScrollModeBottom"
static let ScrollModeUp = "UITextFieldScrollModeUp"
static let ScrollModeMiddle = "UITextFieldScrollModeMiddle"
func scrollToBotom() {
let range = NSMakeRange((text as NSString).length - 1, 1);
scrollRangeToVisible(range);
}
var scrollMode: String {
let scrollViewHeight: Float = Float(frame.size.height)
let scrollContentSizeHeight: Float = Float(contentSize.height)
let scrollOffset: Float = Float(contentOffset.y)
if scrollOffset == 0 {
return UITextView.ScrollModeUp
} else if scrollOffset + scrollViewHeight == scrollContentSizeHeight {
return UITextView.ScrollModeBottom
} else {
return UITextView.ScrollModeMiddle
}
}
}
Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0)

Answer 1

// add to toolbar and render it
let bar = UIToolbar()
bar.setItems([tempItem],
animated: false)
bar.snapshotView(afterScreenUpdates: true)
//got image from real uibutton
let itemView = tempItem.value(forKey: "view") as! UIView
for view in itemView.subviews {
if let button = view as? UIButton,
let image = button.imageView?.image {
return image.withRenderingMode(.alwaysTemplate)
}
}
return nil
}
}