xcode 无法识别的选择器发送到实例 0x7f90f1f04180

unrecognized selector sent to instance 0x7f90f1f04180

提问by iceman

I'm a newbie to swift. I'm using xcode version 8 beta 4. I'm having an error whenever I scroll through my Date Picker. I have read a very similar problem, but the answer there is not fixing my problem. Below is my code:

我是 swift 的新手。我使用的是 xcode 版本 8 beta 4。每当我滚动我的日期选择器时都会出错。我已经阅读了一个非常相似的问题，但那里的答案并没有解决我的问题。下面是我的代码：

func textFieldDidBeginEditing(_ textField: UITextField) {
    let datePicker = UIDatePicker()
    textField.inputView = datePicker
    datePicker.addTarget(self, action: Selector("datePickerChanged:"), for: .valueChanged)        
}

func datePickerChanged(sender: UIDatePicker){
    let formatter = DateFormatter()
    formatter.dateStyle = .long
    dateLog.text = formatter.string(from: sender.date)
}

when I click on my textfield the UIDatePickeris showing up just fine, but when I start to scroll through the dates, it gives me the following error:

当我点击我的文本字段时，UIDatePicker它显示得很好，但是当我开始滚动日期时，它给了我以下错误：

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[MyApp.ViewController datePickerChanged:]: unrecognized selector sent to instance 0x7f90f1f04180'

*** 由于未捕获的异常“NSInvalidArgumentException”而终止应用程序，原因：“-[MyApp.ViewController datePickerChanged:]：无法识别的选择器发送到实例 0x7f90f1f04180”

回答by Sweeper

Selector(String)is deprecated. You should start using the new syntax #selector.

Selector(String)已弃用。您应该开始使用新语法#selector。

Also, the colon at the end is not needed.

此外，不需要末尾的冒号。

So, your code should look like this:

所以，你的代码应该是这样的：

datePicker.addTarget(self, action: #selector(datePickerChanged), 
    for: .valueChanged)

回答by hariszaman

1. change the Selectorto #selector
2. change forto forControlEvents

3. change .valueChangedto .ValueChanged

   datePicker.addTarget(self, action: #selector(yourClass.datePickerChanged), forControlEvents: .ValueChanged) 
   

1. 更改Selector为#selector
2. 更改for为forControlEvents

3. 更改.valueChanged为.ValueChanged

   datePicker.addTarget(self, action: #selector(yourClass.datePickerChanged), forControlEvents: .ValueChanged)