考虑这种情况,假设你有一个 UIView 的子类和一个协议,即
protocol MyViewProtocol
{
func didTapSelf(thisView: MyView)
}
class MyView: UIView
{
lazy var tf: UITextField =
{
let obj = UITextField()
obj.translatesAutoresizingMaskIntoConstraints = false
obj.placeholder = "Enter text"
obj.backgroundColor = .white
return obj
}()
var btn: UIButton =
{
let obj = UIButton()
obj.translatesAutoresizingMaskIntoConstraints = false
obj.addTarget(self, action: #selector(didTapBtn), for: .touchUpInside)
obj.backgroundColor = .orange
return obj
}()
var delegate: MyViewProtocol?
init(backgroundColor: UIColor, placeholder: String, delegate: MyViewProtocol?)
{
super.init(frame: .zero)
self.backgroundColor = backgroundColor
self.delegate = delegate
tf.placeholder = placeholder
configureUI()
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func configureUI()
{
addAllSubviews(tf,
btn)
NSLayoutConstraint.activate([
btn.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 12),
btn.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -12),
btn.topAnchor.constraint(equalTo: topAnchor, constant: 32),
tf.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 12),
tf.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -12),
tf.topAnchor.constraint(equalTo: btn.bottomAnchor, constant: 12),
tf.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -12),
tf.heightAnchor.constraint(equalToConstant: 44)
])
// let gesture = UITapGestureRecognizer(target: self, action: #selector(didTapBtn))
// gesture.cancelsTouchesInView = false
// addGestureRecognizer(gesture)
}
@objc func didTapBtn()
{
delegate?.didTapSelf(thisView: self)
}
}
现在,在您的视图控制器中,创建 2 个 MyView 实例,即
lazy var myView1: MyView =
{
let obj = MyView(backgroundColor: .yellow, placeholder: "view 1", delegate: self)
obj.translatesAutoresizingMaskIntoConstraints = false
return obj
}()
lazy var myView2: MyView =
{
let obj = MyView(backgroundColor: .green, placeholder: "view 2", delegate: self)
obj.translatesAutoresizingMaskIntoConstraints = false
return obj
}()
并使用如下协议方法实现您的视图控制器:
extension ViewController: MyViewProtocol
{
func didTapSelf(thisView: MyView)
{
if thisView == myView1
{
print("tapped view 1")
}
else if thisView == myView2
{
print("tapped view 2")
}
else
{
print("i am ambigious")
}
}
}
现在,当您点击 myView1
或 myView2
中的按钮时,它将正确打印,即点击视图 1 或 2,无论点击哪个按钮,但是当您开始编辑 myView1
文本字段时而在编辑状态的时候,无论你点击myView1
或myView2
中的哪个按钮,它只会打印点击的视图1,或者文本字段处于编辑模式的任何视图。>
据我所知,无论 textField 的编辑状态如何,它都必须传递正确的 self 对象。为什么会发生这种行为?
p.s 当您在上述任何视图上使用点击手势时,不会发生此行为。
答案 0 :(得分:2)
这实际上与协议或故事中的任何其他红鲱鱼无关。稍微调试一下就会发现,实际上正在点击正确的按钮,但运行时实际上是将目标操作消息发送到错误的 MyView。根本原因是在这一行:
obj.addTarget(self, action: #selector(didTapBtn), for: .touchUpInside)
...术语 self
并不意味着您认为它的作用。
要解决问题,只需更改
var btn: UIButton =
到
lazy var btn: UIButton =