iOS: How to detect keyboard change event

问题

Xcode 9.2, iOS 10.0+ , swift4.

I'm working on a project where user inputs english characters in UITextField and it converted to Japanese language characters. and it is working perfect. now, i want to allow user to input Japanese language characters direct from Japanese Keyboard.In this situation i want to know that the keyboard is changed from default to another type/language.

So, is there any function or Notification is available that can help me?

回答1:

You can use the UITextInputCurrentInputModeDidChange notification to detect when the current keyboard language changes.

NotificationCenter.default.addObserver(self, selector: #selector(inputModeDidChange), name: .UITextInputCurrentInputModeDidChange, object: nil)

@objc func inputModeDidChange(_ notification: Notification) {
    if let inputMode = notification.object as? UITextInputMode {
        if let lang = inputMode.primaryLanguage {
            // do something
        }
    }
}

回答2:

UITextInputCurrentInputModeDidChangeNotification

And anytime the keyboard language changes, you'll receive a notification. You can get more info from UITextInputMode docs.

回答3:

With recent changes to iOS 12, swift 5.0 you can try:

func prepareForKeyboardChangeNotification() {
    NotificationCenter.default.addObserver(self, selector: #selector(changeInputMode), name: UITextInputMode.currentInputModeDidChangeNotification, object: nil)
}

@objc
func changeInputMode(notification: NSNotification) {
    let inputMethod = txtInput.textInputMode?.primaryLanguage
    //perform your logic here

}

回答4:

In newer Swift versions the notification has been renamed to UITextInputMode.currentInputModeDidChangeNotification

来源：https://stackoverflow.com/questions/51896904/ios-how-to-detect-keyboard-change-event

标签

ios

swift

uikeyboard