我收到此消息：
[UITextField retain]：发送到解除分配的实例的消息。
我理解这条消息但我不知道发送了什么“消息”以及如何阻止它发生....
此代码产生错误：
func dismissController() {
self.view.endEditing(true)
self.dismissViewControllerAnimated(false, completion: nil)
}
虽然以下工作“很好”，但我不确定为什么在解雇控制器之前我必须延迟：
func dismissController() {
self.view.endEditing(true)
let delay = 0.75 * Double(NSEC_PER_SEC)
let time = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))
dispatch_after(time, dispatch_get_main_queue()) { () -> Void in
self.dismissViewControllerAnimated(false, completion: nil)
}
}
编辑:(几乎完整的代码）：
@IBOutlet weak var locationTextView: UITextField!
@IBOutlet weak var userIDTextView: UITextField!
var treeLocationArray = NSMutableArray()
var treeUserIDArray = NSMutableArray()
让pickerView = UIPickerView（） var pickerButton = UIButton（） var keyboardButton = UIButton（） var locationIsSelected = true
override func viewDidLoad() {
super.viewDidLoad()
//....
locationTextView.delegate = self
userIDTextView.delegate = self
//Get the Plist... etc
treeLocationArray = dict?.objectForKey("Location") as! NSMutableArray
treeUserIDArray = dict?.objectForKey("UserID") as! NSMutableArray
locationTextView.text = userPrefs.objectForKey("DefaultLocation") as? String
userIDTextView.text = userPrefs.objectForKey("DefaultName") as? String
locationTextView.text = userPrefs.objectForKey("DefaultLocation") as? String
/// Create a view for the Accessory View
let customView = UIView(frame: CGRectMake(0, 0, 10, 50))
customView.backgroundColor = UIColor.lightGrayColor()
/// Setup the picker button
pickerButton = UIButton(frame: CGRectMake(60 , 8, 32, 32) )
pickerButton.setImage(UIImage(named:"dropIcon"), forState: .Normal)
pickerButton.tintColor = UIColor.blueColor()
pickerButton.addTarget(self, action: #selector(UserDefaultsViewController.pickerTapped), forControlEvents: UIControlEvents.TouchUpInside)
customView.addSubview(pickerButton)
/// Setup the keyboard button
keyboardButton = UIButton(frame: CGRectMake(10 , 8, 32, 32) )
keyboardButton.setImage(UIImage(named:"keyboardIcon"), forState: .Normal)
keyboardButton.tintColor = UIColor.blueColor()
keyboardButton.addTarget(self, action: #selector(UserDefaultsViewController.keyboardTapped), forControlEvents: UIControlEvents.TouchUpInside)
customView.addSubview(keyboardButton)
locationTextView.inputAccessoryView = customView
userIDTextView.inputAccessoryView = customView
}
func textFieldDidBeginEditing(textField: UITextField) {
if textField == locationTextView {
locationIsSelected = true
}
if textField == userIDTextView {
locationIsSelected = false
}
self.pickerView.reloadAllComponents()
}
func keyboardTapped(){
if locationIsSelected {
locationTextView.resignFirstResponder()
locationTextView.inputView = nil
locationTextView.becomeFirstResponder()
}
else {
userIDTextView.resignFirstResponder()
userIDTextView.inputView = nil
userIDTextView.becomeFirstResponder()
}
}
func pickerTapped(){
if locationIsSelected {
locationTextView.resignFirstResponder()
locationTextView.inputView = nil
locationTextView.inputView = pickerView
locationTextView.becomeFirstResponder()
}
else {
userIDTextView.resignFirstResponder()
userIDTextView.inputView = nil
userIDTextView.inputView = pickerView
userIDTextView.becomeFirstResponder()
}
}
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
var numberOfComponents = Int()
if locationIsSelected {
numberOfComponents = treeLocationArray.count
}
else {
numberOfComponents = treeUserIDArray.count
}
return numberOfComponents
}
func pickerView(pickerView: UIPickerView, numberOfRowsInSection section: Int) -> Int {
var numberOfComponents = Int()
if locationIsSelected {
numberOfComponents = treeLocationArray.count
}
else {
numberOfComponents = treeUserIDArray.count
}
return numberOfComponents
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
var componetString = String()
if locationIsSelected {
componetString = (treeLocationArray[row] as? String)!
}
else {
componetString = (treeUserIDArray[row] as? String)!
}
return componetString
}
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if locationIsSelected {
if treeLocationArray.count >= 1 {
locationTextView.text = treeLocationArray[row] as? String
}
}
else {
if treeUserIDArray.count >= 1 {
userIDTextView.text = treeUserIDArray[row] as? String
}
}
}
答案 0 :(得分：1)
发生此问题是因为您已调用dismissViewControllerAnimated。由于VC生命周期，此VC保存的所有对象将被释放。这意味着，在解雇后使用UI进行的所有操作都不是内存安全的。
来自文档：
此方法查看当前视图及其子视图层次结构 当前第一个响应者的文本字段。如果找到一个， 它要求文本字段作为第一响应者辞职。如果力量 参数设置为true，文本字段永远不会被询问;它是 被迫辞职。
因此，我认为你的VC已被解除分配，而endEditing正在寻找彻底的层次结构。这是唯一可能导致记忆问题的原因之一。
为什么在解雇前需要调用endEditing？如果没有这个电话，只需解雇VC。如果你有逻辑，那取决于endEditing - 将它分开并调用而不是endEditing。希望这会有所帮助。
更新：
尝试在viewWillDisappear中调用endEditing - 这会触发视图，在第一个响应者被解雇之前将其重新签名。