ios - Textview 不响应其各自的功能

Question

我在看 Text View Placeholder Swift .在我看来，我做了这篇文章告诉我要做的一切。但是，它不起作用。更具体地说，textViewDidBeginEditing() 和 textViewDidEndEditing() 函数没有执行。我认为这是因为我编写了 println("hello") 和 println("YO") 但它没有向控制台打印任何内容。有人有解决此问题的解决方案吗？

这是我的代码:

import UIKit

class WritePrayerRequestViewController: UIViewController, UITextViewDelegate {

    @IBOutlet weak var writePrayerRequestTextView: UITextView!

    override func viewDidLoad() {
        super.viewDidLoad()
        writePrayerRequestTextView.becomeFirstResponder()
        writePrayerRequestTextView.layer.borderWidth = 0.5
        writePrayerRequestTextView.layer.borderColor = UIColor.lightGrayColor().CGColor
        writePrayerRequestTextView.layer.cornerRadius = 7
        writePrayerRequestTextView.textColor = UIColor.lightGrayColor()
        writePrayerRequestTextView.text = "Write your prayer request here."
    }

    func textViewDidBeginEditing(writePrayerRequestTextView: UITextView) {
        println("hello")
        if writePrayerRequestTextView.textColor == UIColor.lightGrayColor() {
            writePrayerRequestTextView.text = nil
            writePrayerRequestTextView.textColor = UIColor.blackColor()
        }
    }

    func textViewDidEndEditing(textView: UITextView) {
        println("YO")
        if textView.text.isEmpty {
            textView.text = "Write your prayer request here."
            textView.textColor = UIColor.lightGrayColor()
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}

Answer 1

您确定 UITextView 的委托(delegate)已正确分配吗？例如 writePrayerRequestTextView.delegate = self 在 vi​​ewDidLoad