macos - 如何实时检查 NSTextField - Swift OS X

Question

我目前正在制作一个用 Swift 编写的 OS X 应用程序。我想要做的是，当用户在 NSTextField 中输入文本时，我想运行一个函数来检查该值并将其添加到标签中。我该如何快速做到这一点？

Answer 1

1. 使 ViewController 符合协议(protocol) NSTextDelegate。
2. 将 ViewController 指定为 TextField 的委托(delegate)。

3. 实现 controlTextDidChange 方法。

   import Cocoa
   
   @NSApplicationMain
   class AppDelegate: NSObject, NSApplicationDelegate, NSTextFieldDelegate {
   
       @IBOutlet weak var window: NSWindow!
       @IBOutlet weak var textField: NSTextField!
       @IBOutlet weak var label: NSTextField!
   
   
       func applicationDidFinishLaunching(aNotification: NSNotification)
       {
           textField.delegate = self
       }
   
       override func controlTextDidChange(notification: NSNotification)
       {
           let object = notification.object as! NSTextField
           self.label.stringValue = object.stringValue
       }
   
       func applicationWillTerminate(aNotification: NSNotification) {
           // Insert code here to tear down your application
       }
   }
   

在 View Controller 中:

import Cocoa

class ViewController: NSViewController, NSTextDelegate {

   @IBOutlet weak var label: NSTextField!
   @IBOutlet weak var label2: NSTextField!
   @IBOutlet weak var textField: NSTextField!
   @IBOutlet weak var textField2: NSTextField!

   override func viewDidLoad() {
      super.viewDidLoad()
   }

   override func controlTextDidChange(notification: NSNotification) {
      if let txtFld = notification.object as? NSTextField {
         switch txtFld.tag {
         case 201:
            self.label.stringValue = txtFld.stringValue
         case 202:
            self.label2.stringValue = txtFld.stringValue
         default:
            break
         }
      }
   }
}