新增拼写功能：出题随机空缺字母，用户输入完整单词

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

LearnEnglish/LearnEnglish/Models/Quiz.swift

@@ -3,6 +3,7 @@ import Foundation
 enum QuizMode: String, Hashable {
     case enToZh = "英选汉"
     case zhToEn = "汉选英"
+    case spelling = "拼写"
 }
 
 struct QuizSetupRequest: Hashable {
@@ -21,6 +22,7 @@ struct QuizQuestion: Identifiable {
     let prompt: String
     let options: [String]
     let answer: String
+    let blankedWord: String
 }
 
 enum QuizGenerator {
@@ -32,16 +34,34 @@ enum QuizGenerator {
                 word: word,
                 prompt: promptText(word, mode),
                 options: options,
-                answer: optionText(word, mode)
+                answer: optionText(word, mode),
+                blankedWord: mode == .spelling ? blankWord(word.word) : ""
             )
         }
     }
 
     private static func promptText(_ word: Word, _ mode: QuizMode) -> String {
-        mode == .enToZh ? word.word : word.meaning
+        switch mode {
+        case .enToZh: return word.word
+        case .zhToEn: return word.meaning
+        case .spelling: return word.meaning
+        }
     }
 
     private static func optionText(_ word: Word, _ mode: QuizMode) -> String {
-        mode == .enToZh ? word.meaning : word.word
+        switch mode {
+        case .enToZh: return word.meaning
+        case .zhToEn: return word.word
+        case .spelling: return word.word
+        }
+    }
+
+    private static func blankWord(_ word: String) -> String {
+        let chars = Array(word)
+        let count = chars.count
+        guard count > 2 else { return String(repeating: "_", count: count) }
+        let blanks = max(1, Int(Double(count) * 0.4))
+        let indices = Set(Array(0..<count).shuffled().prefix(blanks))
+        return chars.enumerated().map { indices.contains($0.offset) ? "_" : String($0.element) }.joined()
     }
 }

LearnEnglish/LearnEnglish/Views/QuizView.swift

@@ -9,6 +9,7 @@ struct QuizView: View {
     @State private var questions: [QuizQuestion]
     @State private var currentIndex = 0
     @State private var selectedOption: String?
+    @State private var userInput = ""
     @State private var wrongWords: [Word] = []
     @State private var finished = false
     @State private var startDate = Date.now
@@ -67,6 +68,44 @@ struct QuizView: View {
             .frame(maxWidth: .infinity)
             .padding(.vertical, 24)
 
+            if config.mode == .spelling {
+                spellingView(question)
+            } else {
+                optionsView(question)
+            }
+
+            if let selectedOption {
+                VStack(spacing: 12) {
+                    if config.mode == .spelling {
+                        Text(selectedOption == question.answer ? "正确" : "正确答案：\(question.answer)")
+                            .font(.title2.weight(.bold))
+                            .foregroundStyle(selectedOption == question.answer ? .green : .red)
+                        Text(question.word.phonetic)
+                            .font(.subheadline)
+                            .foregroundStyle(.secondary)
+                    } else {
+                        Text(selectedOption == question.answer ? "回答正确" : "正确答案：\(question.answer)")
+                            .font(.headline)
+                            .foregroundStyle(selectedOption == question.answer ? .green : .red)
+                    }
+                    Button {
+                        next()
+                    } label: {
+                        Text(currentIndex + 1 < questions.count ? "下一题" : "查看成绩")
+                            .frame(maxWidth: .infinity)
+                            .frame(height: 44)
+                    }
+                    .buttonStyle(.borderedProminent)
+                    .font(.headline)
+                }
+            }
+
+            Spacer()
+        }
+        .padding()
+    }
+
+    private func optionsView(_ question: QuizQuestion) -> some View {
         VStack(spacing: 12) {
             ForEach(question.options, id: \.self) { option in
                 Button {
@@ -89,27 +128,33 @@ struct QuizView: View {
                 .disabled(selectedOption != nil)
             }
         }
+    }
 
-            if let selectedOption {
+    private func spellingView(_ question: QuizQuestion) -> some View {
-                VStack(spacing: 12) {
+        VStack(spacing: 16) {
-                    Text(selectedOption == question.answer ? "回答正确" : "正确答案：\(question.answer)")
+            Text(question.blankedWord)
-                        .font(.headline)
+                .font(.system(size: 44, weight: .bold, design: .monospaced))
-                        .foregroundStyle(selectedOption == question.answer ? .green : .red)
+                .tracking(6)
-                    Button {
+            Text("\(question.word.word.count) 个字母")
-                        next()
+                .font(.subheadline)
-                    } label: {
+                .foregroundStyle(.secondary)
-                        Text(currentIndex + 1 < questions.count ? "下一题" : "查看成绩")
+            HStack(spacing: 12) {
-                            .frame(maxWidth: .infinity)
+                TextField("输入完整单词", text: $userInput)
-                            .frame(height: 44)
+                    .textFieldStyle(.roundedBorder)
+                    .autocapitalization(.none)
+                    .disableAutocorrection(true)
+                    .disabled(selectedOption != nil)
+                Button("确认") {
+                    guard !userInput.trimmingCharacters(in: .whitespaces).isEmpty else { return }
+                    selectedOption = userInput.trimmingCharacters(in: .whitespaces).lowercased()
+                    if selectedOption != question.answer {
+                        wrongWords.append(question.word)
+                    }
                 }
                 .buttonStyle(.borderedProminent)
-                    .font(.headline)
+                .disabled(userInput.trimmingCharacters(in: .whitespaces).isEmpty || selectedOption != nil)
             }
         }
-
-            Spacer()
-        }
-        .padding()
     }
 
     private func optionColor(_ option: String, for question: QuizQuestion) -> Color {
@@ -131,6 +176,7 @@ struct QuizView: View {
         if currentIndex + 1 < questions.count {
             currentIndex += 1
             selectedOption = nil
+            userInput = ""
         } else {
             finished = true
         }
@@ -140,6 +186,7 @@ struct QuizView: View {
         questions = QuizGenerator.makeQuestions(mode: config.mode, words: config.words)
         currentIndex = 0
         selectedOption = nil
+        userInput = ""
         wrongWords = []
         finished = false
         startDate = .now

LearnEnglish/LearnEnglish/Views/WordListView.swift

@@ -25,6 +25,7 @@ struct WordListView: View {
                 Menu {
                     Button("英选汉") { startQuiz(.enToZh) }
                     Button("汉选英") { startQuiz(.zhToEn) }
+                    Button("拼写") { startQuiz(.spelling) }
                 } label: {
                     Text("测验")
                 }