新增默写功能，播放按钮移到导航栏，输入框改为下边框样式

LearnEnglish/LearnEnglish/Views/QuizViewController.swift

@@ -17,6 +17,7 @@ final class QuizViewController: UIViewController {
     private let speakerButton = UIButton(type: .system)
     private let optionsStack = UIStackView()
     private let spellingView = SpellingInputView()
+    private let dictationView = DictationInputView()
     private let spellingHintLabel = UILabel()
     private let resultLabel = UILabel()
     private let resultPhoneticLabel = UILabel()
@@ -48,6 +49,8 @@ final class QuizViewController: UIViewController {
         super.viewDidAppear(animated)
         if config.mode == .spelling, selectedOption == nil {
             spellingView.activate()
+        } else if config.mode == .dictation, selectedOption == nil {
+            dictationView.activate()
         }
     }
 
@@ -91,6 +94,13 @@ final class QuizViewController: UIViewController {
         nextButton.configuration = nextConfig
         nextButton.addAction(UIAction { [weak self] _ in self?.primaryButtonTapped() }, for: .touchUpInside)
 
+        navigationItem.rightBarButtonItem = UIBarButtonItem(
+            image: UIImage(systemName: "speaker.wave.2.fill"),
+            style: .plain,
+            target: self,
+            action: #selector(speakCurrentWord)
+        )
+
         let headerStack = UIStackView(arrangedSubviews: [progressView, countLabel])
         headerStack.axis = .vertical
         headerStack.spacing = 8
@@ -100,7 +110,7 @@ final class QuizViewController: UIViewController {
         promptStack.spacing = 12
         promptStack.alignment = .center
 
-        let inputStack = UIStackView(arrangedSubviews: [optionsStack, spellingView, spellingHintLabel])
+        let inputStack = UIStackView(arrangedSubviews: [optionsStack, spellingView, dictationView, spellingHintLabel])
         inputStack.axis = .vertical
         inputStack.spacing = 16
 
@@ -138,8 +148,11 @@ final class QuizViewController: UIViewController {
         resultPhoneticLabel.isHidden = true
 
         let isSpelling = config.mode == .spelling
-        optionsStack.isHidden = isSpelling
+        let isDictation = config.mode == .dictation
+        let isChoice = !isSpelling && !isDictation
+        optionsStack.isHidden = !isChoice
         spellingView.isHidden = !isSpelling
+        dictationView.isHidden = !isDictation
         spellingHintLabel.isHidden = !isSpelling
 
         if isSpelling {
@@ -153,6 +166,20 @@ final class QuizViewController: UIViewController {
             nextButton.isEnabled = false
             nextButton.isHidden = false
             spellingView.activate()
+        } else if isDictation {
+            dictationView.reset()
+            dictationView.onChange = { [weak self] in
+                guard let self else { return }
+                nextButton.isEnabled = !dictationView.isEmpty
+            }
+            dictationView.onSubmit = { [weak self] in
+                guard let self else { return }
+                primaryButtonTapped()
+            }
+            nextButton.configuration?.title = "确认"
+            nextButton.isEnabled = false
+            nextButton.isHidden = false
+            dictationView.activate()
         } else {
             nextButton.isHidden = true
             buildOptionButtons(for: question)
@@ -213,8 +240,18 @@ final class QuizViewController: UIViewController {
         showResult(typed == question.answer, for: question)
     }
 
+    private func submitDictation(_ typed: String, for question: QuizQuestion) {
+        guard selectedOption == nil else { return }
+        selectedOption = typed
+        if typed != question.answer {
+            wrongWords.append(question.word)
+        }
+        dictationView.deactivate()
+        showResult(typed == question.answer, for: question)
+    }
+
     private func showResult(_ correct: Bool, for question: QuizQuestion) {
-        if config.mode == .spelling {
+        if config.mode == .spelling || config.mode == .dictation {
             resultLabel.text = correct ? "正确" : "正确答案：\(question.answer)"
             resultPhoneticLabel.text = question.word.phonetic
             resultPhoneticLabel.isHidden = false
@@ -229,10 +266,18 @@ final class QuizViewController: UIViewController {
         nextButton.isHidden = false
     }
 
+    @objc private func speakCurrentWord() {
+        guard let question = current else { return }
+        speech.speak(question.answer)
+    }
+
     private func primaryButtonTapped() {
         if config.mode == .spelling, selectedOption == nil {
             guard let question = current, spellingView.isComplete else { return }
             submitSpelling(spellingView.typedWord(), for: question)
+        } else if config.mode == .dictation, selectedOption == nil {
+            guard let question = current, !dictationView.isEmpty else { return }
+            submitDictation(dictationView.text, for: question)
         } else {
             next()
         }
@@ -273,6 +318,8 @@ final class QuizViewController: UIViewController {
         showQuestion()
         if config.mode == .spelling {
             spellingView.activate()
+        } else if config.mode == .dictation {
+            dictationView.activate()
         }
     }
 }