例如,给定文字:
import UIKit
class ViewController: UIViewController {
@IBOutlet weak var textView: UITextView!
var observer: NSKeyValueObservation?
/* ... */
override func viewDidLoad() {
super.viewDidLoad()
let handler = { (textView: UITextView, change: NSKeyValueObservedChange<CGSize>) in
if let contentSize = change.newValue {
print("contentSize:", contentSize)
}
}
observer = textView.observe(\UITextView.contentSize, options: [NSKeyValueObservingOptions.new], changeHandler: handler)
}
}
如果该行包含source: today is monday
target: tomorrow is monday
,我想用'monday'
替换'tuesday'
。