我想在 SwiftUI 中创建一个自定义文本字段来处理第一响应者,但我在代码中遇到此错误并且结构是不可变的我不知道该怎么办?
struct CustomTextField: UIViewRepresentable {
class Coordinator: NSObject, UITextFieldDelegate {
@Binding var text: String
var didBecomeFirstResponder = false
init(txt: Binding<String>) {
self.$text = txt
}
func textFieldDidChangeSelection(_ textField: UITextField) {
text = textField.text ?? ""
}
}
@Binding var text: String
var isFirstResponder: Bool = false
func makeUIView(context: UIViewRepresentableContext<CustomTextField>) -> UITextField {
let textField = UITextField(frame: .zero)
textField.delegate = context.coordinator
return textField
}
func makeCoordinator() -> CustomTextField.Coordinator {
return Coordinator(txt: $text)
}
func updateUIView(_ uiView: UITextField, context: UIViewRepresentableContext<CustomTextField>) {
uiView.text = text
if isFirstResponder && !context.coordinator.didBecomeFirstResponder {
uiView.becomeFirstResponder()
context.coordinator.didBecomeFirstResponder = true
}
}
}
在 beta 4 中,属性包装器的实现发生了变化。
在 beta 3 之前,这是有效的:
self.$text = txt
在 beta 4 中,它更改为:
self._text = txt
检查实施中的差异,在我发布的另一个问题中:
https://stackoverflow.com/a/57088052/7786555 https://stackoverflow.com/a/57088052/7786555
欲了解更多详细信息:
https://stackoverflow.com/a/56975728/7786555 https://stackoverflow.com/a/56975728/7786555
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