我需要使用UIAlertContoller
,因为SwiftUI的Alert
不支持TextField
。
由于各种原因(可访问性,DynamicType,暗模式支持等,我不能使用自定义创建的AlertView。
基本思想是,SwiftUI的警报必须包含TextField
且输入的文本必须反射回来以供使用。
我通过遵循view
来创建SwiftUI UIViewControllerRepresentable
,以下是工作代码。
struct AlertControl: UIViewControllerRepresentable {
typealias UIViewControllerType = UIAlertController
@Binding var textString: String
@Binding var show: Bool
var title: String
var message: String
func makeUIViewController(context: UIViewControllerRepresentableContext<AlertControl>) -> UIAlertController {
let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
alert.addTextField { textField in
textField.placeholder = "Enter some text"
}
let cancelAction = UIAlertAction(title: "cancel", style: .destructive) { (action) in
self.show = false
}
let submitAction = UIAlertAction(title: "Submit", style: .default) { (action) in
self.show = false
}
alert.addAction(cancelAction)
alert.addAction(submitAction)
return alert
}
func updateUIViewController(_ uiViewController: UIAlertController, context: UIViewControllerRepresentableContext<AlertControl>) {
}
func makeCoordinator() -> AlertControl.Coordinator {
Coordinator(self)
}
class Coordinator: NSObject, UITextFieldDelegate {
var control: AlertControl
init(_ control: AlertControl) {
self.control = control
}
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
if let text = textField.text {
self.control.textString = text
}
return true
}
}
}
// SwiftUI View in some content view
AlertControl(textString: self.$text,
show: self.$showAlert,
title: "Title goes here",
message: "Message goes here")
问题:
被点击时,警报措施中没有任何活动。我检查了断点,但它从未击中过。
即使UITextFieldDelegate
的功能也不会被点击。
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool
您忘记了在文本字段配置期间添加委托,因此要修复
alert.addTextField { textField in
textField.placeholder = "Enter some text"
textField.text = self.textString // << initial value if any
textField.delegate = context.coordinator // << use coordinator as delegate
}