使用UIRepresentable协议解决了该问题
 struct TestTextfield: UIViewRepresentable {
    @Binding var text: String
    var keyType: UIKeyboardType
    func makeUIView(context: Context) -> UITextField {
        let textfield = UITextField()
      textfield.keyboardType = keyType
        let toolBar = UIToolbar(frame: CGRect(x: 0, y: 0, width: textfield.frame.size.width, height: 44))
        let doneButton = UIBarButtonItem(title: "Done", style: .done, target: self, action: #selector(textfield.doneButtonTapped(button:)))
        toolBar.items = [doneButton]
        toolBar.setItems([doneButton], animated: true)
        textfield.inputAccessoryView = toolBar
        return textfield
    }
    func updateUIView(_ uiView: UITextField, context: Context) {
        uiView.text = text
    }
}
extension  UITextField{
    @objc func doneButtonTapped(button:UIBarButtonItem) -> Void {
       self.resignFirstResponder()
    }
}
在内容视图中使用
struct ContentView : View {
@State var text = ""
var body: some View {
    TestTextfield(text: $text, keyType: UIKeyboardType.phonePad)
        .frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: 50)
        .overlay(
            RoundedRectangle(cornerRadius: 16)
                .stroke(Color.blue, lineWidth: 4)
    )
}
}