feat(ios): TabBar 隐藏/出现增加平滑动画

- ContentView 新增 TabBarVisibleKey 环境值 + AnimatedTabBarHide modifier
- TabView 使用 .toolbar(visible/hidden) + .animation 驱动动画
- 子页面 onAppear 隐藏 → onDisappear 出现，带 easeInOut 0.28s
- 替换所有静态 .toolbar(.hidden, for: .tabBar) 为 .animatedTabBarHide()

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

AIStudyApp/AIStudyApp/ContentView.swift

@@ -1,7 +1,48 @@
 import SwiftUI
 
+// MARK: - TabBar hide animation key
+
+struct TabBarVisibleKey: EnvironmentKey {
+    static let defaultValue: Binding<Bool> = .constant(false)
+}
+
+extension EnvironmentValues {
+    var isTabBarHidden: Binding<Bool> {
+        get { self[TabBarVisibleKey.self] }
+        set { self[TabBarVisibleKey.self] = newValue }
+    }
+}
+
+/// 子页面添加此 modifier 即可获得带动画的 TabBar 隐藏/出现效果
+struct AnimatedTabBarHide: ViewModifier {
+    @Environment(\.isTabBarHidden) private var isTabBarHidden
+
+    func body(content: Content) -> some View {
+        content
+            .onAppear {
+                withAnimation(.easeInOut(duration: 0.28)) {
+                    isTabBarHidden.wrappedValue = true
+                }
+            }
+            .onDisappear {
+                withAnimation(.easeInOut(duration: 0.28)) {
+                    isTabBarHidden.wrappedValue = false
+                }
+            }
+    }
+}
+
+extension View {
+    func animatedTabBarHide() -> some View {
+        modifier(AnimatedTabBarHide())
+    }
+}
+
+// MARK: - ContentView
+
 struct ContentView: View {
     @State private var selectedTab = "study"
+    @State private var tabBarHidden = false
 
     var body: some View {
         TabView(selection: $selectedTab) {
@@ -42,6 +83,9 @@ struct ContentView: View {
             .tag("profile")
         }
         .tint(Color.zxPrimary)
+        .toolbar(tabBarHidden ? .hidden : .visible, for: .tabBar)
+        .animation(.easeInOut(duration: 0.28), value: tabBarHidden)
+        .environment(\.isTabBarHidden, $tabBarHidden)
     }
 }
 

AIStudyApp/AIStudyApp/Features/AI/AIChatPage.swift

@@ -38,7 +38,7 @@ struct AIChatPage: View {
                     .padding(.horizontal, 20).padding(.bottom, 34)
             }
         }
-        .navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar)
+        .navigationBarTitleDisplayMode(.inline).animatedTabBarHide()
         .toolbarBackground(.hidden, for: .navigationBar)
     }
 

AIStudyApp/AIStudyApp/Features/AI/AIFeedbackPageView.swift

@@ -101,7 +101,7 @@ struct AIFeedbackPageView: View {
                 .transition(.opacity.combined(with: .scale(scale: 0.95)))
             }
         }
-        .navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar)
+        .navigationBarTitleDisplayMode(.inline).animatedTabBarHide()
         .toolbarBackground(.hidden, for: .navigationBar)
     }
 }

AIStudyApp/AIStudyApp/Features/AI/ActiveRecallView.swift

@@ -39,7 +39,7 @@ struct ActiveRecallView: View {
                 .scrollIndicators(.hidden)
             }
         }
-        .navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar)
+        .navigationBarTitleDisplayMode(.inline).animatedTabBarHide()
         .toolbarBackground(.hidden, for: .navigationBar)
         .task { await viewModel.loadQuestions() }
         .overlay {

AIStudyApp/AIStudyApp/Features/AI/DailyThinkingPage.swift

@@ -12,6 +12,6 @@ struct DailyThinkingPage: View {
                 VStack(alignment:.leading,spacing:8){Text("你的回答").font(.system(size:13,weight:.semibold)).foregroundColor(Color.zxF04);TextEditor(text:$answer).zxFontScaled(size:13).foregroundColor(Color.zxF0).tint(Color.zxPurple).frame(minHeight:160).scrollContentBackground(.hidden).padding(12).background(Color.zxFill004).clipShape(RoundedRectangle(cornerRadius:14)).overlay(RoundedRectangle(cornerRadius:14).stroke(Color.zxBorder008,lineWidth:1))}
                 if !submitted{ NavigationLink(value: Route.aiFeedback){ Text("提交回答，获取 AI 反馈").font(.system(size:14,weight:.bold)).foregroundColor(.white).frame(maxWidth:.infinity).frame(height:52).background(ZXGradient.ctaPurple).clipShape(RoundedRectangle(cornerRadius:16)).shadow(color:Color(hex:"#7C6EFA",opacity:0.3),radius:24) }.zxPressable() }
             }.padding(.horizontal,20).padding(.top, 8).padding(.bottom,120) }.scrollIndicators(.hidden)
-        }.navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar).toolbarBackground(.hidden,for:.navigationBar)
+        }.navigationBarTitleDisplayMode(.inline).animatedTabBarHide().toolbarBackground(.hidden,for:.navigationBar)
     }
 }

AIStudyApp/AIStudyApp/Features/AI/RecallTestPage.swift

@@ -32,7 +32,7 @@ struct RecallTestPage: View {
             }
             .scrollIndicators(.hidden)
         }
-        .navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar)
+        .navigationBarTitleDisplayMode(.inline).animatedTabBarHide()
         .toolbarBackground(.hidden, for: .navigationBar)
     }
 }

AIStudyApp/AIStudyApp/Features/AI/WeakPointsPage.swift

@@ -16,7 +16,7 @@ struct WeakPointsPage: View {
             }
             .scrollIndicators(.hidden)
         }
-        .navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar)
+        .navigationBarTitleDisplayMode(.inline).animatedTabBarHide()
         .toolbarBackground(.hidden, for: .navigationBar)
     }
 }

AIStudyApp/AIStudyApp/Features/Library/LibraryHomeView.swift

@@ -81,6 +81,6 @@ struct LibrarySearchView: View {
                     }
                 }.padding(.horizontal, 20) }.scrollIndicators(.hidden)
             }
-        }.navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar).toolbarBackground(.hidden, for: .navigationBar)
+        }.navigationBarTitleDisplayMode(.inline).animatedTabBarHide().toolbarBackground(.hidden, for: .navigationBar)
     }
 }

AIStudyApp/AIStudyApp/Features/Library/LibrarySubpages.swift

@@ -36,7 +36,7 @@ struct CreateLibraryPage: View {
                 }
                 .disabled(isCreating || name.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty)
             }.padding(.horizontal, 20).padding(.top, 20) }.scrollIndicators(.hidden) }
-        }.navigationBarTitleDisplayMode(.inline).toolbarBackground(.hidden, for: .navigationBar).toolbar(.hidden, for: .tabBar)}
+        }.navigationBarTitleDisplayMode(.inline).toolbarBackground(.hidden, for: .navigationBar).animatedTabBarHide()}
 }
 
 struct LibraryDetailPage: View {
@@ -68,7 +68,7 @@ struct LibraryDetailPage: View {
             .scrollIndicators(.hidden)
             .zxPullToRefresh { await viewModel.refresh(knowledgeBaseId: knowledgeBaseId) } }
         }
-        .navigationBarTitleDisplayMode(.inline).toolbarBackground(.hidden, for: .navigationBar).toolbar(.hidden, for: .tabBar)
+        .navigationBarTitleDisplayMode(.inline).toolbarBackground(.hidden, for: .navigationBar).animatedTabBarHide()
         .toolbar {
             ToolbarItem(placement: .topBarTrailing) {
                 NavigationLink(value: Route.addKnowledge(knowledgeBaseId: knowledgeBaseId)) {
@@ -226,7 +226,7 @@ struct AddKnowledgePage: View {
                 .disabled(!canSave || isSaving)
             }.padding(.horizontal, 20).padding(.top, 8).padding(.bottom, 80) }.scrollIndicators(.hidden) }
         }
-        .navigationBarTitleDisplayMode(.inline).toolbarBackground(.hidden, for: .navigationBar).toolbar(.hidden, for: .tabBar)
+        .navigationBarTitleDisplayMode(.inline).toolbarBackground(.hidden, for: .navigationBar).animatedTabBarHide()
         .fileImporter(isPresented: $showFilePicker, allowedContentTypes: [.plainText, .pdf, .image], allowsMultipleSelection: false) { result in
             if case .success(let urls) = result, let url = urls.first { handleFile(url) }
         }
@@ -382,7 +382,7 @@ struct KnowledgeDetailPage: View {
                     }
                 }
             }.padding(.horizontal, 20).padding(.bottom, 80) }.scrollIndicators(.hidden) }
-        }.navigationBarTitleDisplayMode(.inline).toolbarBackground(.hidden, for: .navigationBar).toolbar(.hidden, for: .tabBar)}
+        }.navigationBarTitleDisplayMode(.inline).toolbarBackground(.hidden, for: .navigationBar).animatedTabBarHide()}
 }
 struct ZXChip: View { let text: String; let color: Color
     var body: some View { Text(text).font(.system(size: 10, weight: .semibold)).foregroundColor(color).padding(.horizontal, 8).padding(.vertical, 2).background(color.opacity(0.12)).clipShape(Capsule()) }
@@ -397,7 +397,7 @@ struct ImportPage: View {
                 ZXImportOption(icon: "link", title: "链接导入", desc: "粘贴网页链接，自动提取内容")
                 ZXImportOption(icon: "photo.on.rectangle", title: "相册导入", desc: "从相册选择截图或图片")
             }.padding(.horizontal, 20).padding(.top, 8) }.scrollIndicators(.hidden) }
-        }.navigationBarTitleDisplayMode(.inline).toolbarBackground(.hidden, for: .navigationBar).toolbar(.hidden, for: .tabBar)}
+        }.navigationBarTitleDisplayMode(.inline).toolbarBackground(.hidden, for: .navigationBar).animatedTabBarHide()}
 }
 struct ZXImportOption: View { let icon: String; let title: String; let desc: String
     var body: some View { Button { } label: { HStack(spacing: 14) { Image(systemName: icon).font(.system(size: 22)).foregroundColor(Color.zxPurple).frame(width: 48, height: 48).background(Color.zxPurpleBG(0.1)).clipShape(RoundedRectangle(cornerRadius: 14)); VStack(alignment: .leading, spacing: 2) { Text(title).font(.system(size: 15, weight: .semibold)).foregroundColor(Color.zxF0); Text(desc).font(.system(size: 12)).foregroundColor(Color.zxF04) }; Spacer(); Image(systemName: "chevron.right").font(.system(size: 12)).foregroundColor(Color.zxF03) }.padding(16).background(Color.zxFill003).clipShape(RoundedRectangle(cornerRadius: 16)).overlay(RoundedRectangle(cornerRadius: 16).stroke(Color.zxBorder006, lineWidth: 1)) }.foregroundColor(.primary) }
@@ -421,5 +421,5 @@ struct EditKnowledgePage: View {
                     Task { _ = try? await KnowledgeItemService.shared.update(id: item.id, title: title, content: content, summary: nil) }
                 } label: { Text("保存修改").font(.system(size: 14, weight: .bold)).foregroundColor(.white).frame(maxWidth: .infinity).frame(height: 52).background(ZXGradient.ctaPurple).clipShape(RoundedRectangle(cornerRadius: 16)) }
             }.padding(.horizontal, 20).padding(.top, 8).padding(.bottom, 80) }.scrollIndicators(.hidden) }
-        }.navigationBarTitleDisplayMode(.inline).toolbarBackground(.hidden, for: .navigationBar).toolbar(.hidden, for: .tabBar)}
+        }.navigationBarTitleDisplayMode(.inline).toolbarBackground(.hidden, for: .navigationBar).animatedTabBarHide()}
 }

AIStudyApp/AIStudyApp/Features/Profile/EditProfilePage.swift

@@ -142,7 +142,7 @@ struct EditProfilePage: View {
         }
         .navigationTitle("编辑资料")
         .navigationBarTitleDisplayMode(.inline)
-        .toolbar(.hidden, for: .tabBar)
+        .animatedTabBarHide()
         .toolbarBackground(.hidden, for: .navigationBar)
         .photosPicker(isPresented: $showPhotoPicker, selection: $selectedPhotoItem, matching: .images)
         .onChange(of: selectedPhotoItem) { _, item in

AIStudyApp/AIStudyApp/Features/Profile/FeedbackFormView.swift

@@ -39,6 +39,6 @@ struct FeedbackFormView: View {
                     .disabled(isSubmitting)
                 }.padding(.horizontal, 20).padding(.top, 8).padding(.bottom, 80)
             }.scrollIndicators(.hidden)
-        }.navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar).toolbarBackground(.hidden, for: .navigationBar)
+        }.navigationBarTitleDisplayMode(.inline).animatedTabBarHide().toolbarBackground(.hidden, for: .navigationBar)
     }
 }

AIStudyApp/AIStudyApp/Features/Profile/GoalSettingDetailView.swift

@@ -49,6 +49,6 @@ struct GoalSettingDetailView: View {
                     .disabled(isSaving)
                 }.padding(.horizontal, 20).padding(.top, 8).padding(.bottom, 80)
             }.scrollIndicators(.hidden)
-        }.navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar).toolbarBackground(.hidden, for: .navigationBar)
+        }.navigationBarTitleDisplayMode(.inline).animatedTabBarHide().toolbarBackground(.hidden, for: .navigationBar)
     }
 }

AIStudyApp/AIStudyApp/Features/Profile/MethodPreferenceView.swift

@@ -46,6 +46,6 @@ struct MethodPreferenceView: View {
                     .disabled(isSaving)
                 }.padding(.horizontal, 20).padding(.top, 8).padding(.bottom, 80)
             }.scrollIndicators(.hidden)
-        }.navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar).toolbarBackground(.hidden, for: .navigationBar)
+        }.navigationBarTitleDisplayMode(.inline).animatedTabBarHide().toolbarBackground(.hidden, for: .navigationBar)
     }
 }

AIStudyApp/AIStudyApp/Features/Profile/NotificationListView.swift

@@ -38,7 +38,7 @@ struct NotificationListView: View {
             .scrollIndicators(.hidden)
             .zxPullToRefresh { await refresh() }
         }
-        .navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar)
+        .navigationBarTitleDisplayMode(.inline).animatedTabBarHide()
         .toolbarBackground(.hidden, for: .navigationBar)
         .task { await loadNotifications() }
     }

AIStudyApp/AIStudyApp/Features/Profile/SettingsView.swift

@@ -115,7 +115,7 @@ struct SettingsView: View {
             notificationEnabled = p.notificationEnabled ?? true
             reviewReminder = notificationEnabled
         }
-        .navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar).toolbarBackground(.hidden, for: .navigationBar)
+        .navigationBarTitleDisplayMode(.inline).animatedTabBarHide().toolbarBackground(.hidden, for: .navigationBar)
     }
 
     private func sectionHeader(_ text: String) -> some View {

AIStudyApp/AIStudyApp/Features/Study/LearningSessionView.swift

@@ -36,7 +36,7 @@ struct LearningSessionView: View {
                 bottomBar
             }.ignoresSafeArea(edges: .bottom)
         }
-        .navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar)
+        .navigationBarTitleDisplayMode(.inline).animatedTabBarHide()
         .toolbarBackground(.hidden, for: .navigationBar)
         .onReceive(timer) { _ in
             if isRunning { elapsed += 1 }

AIStudyApp/AIStudyApp/Features/Study/ReviewCardView.swift

@@ -40,7 +40,7 @@ struct ReviewCardView: View {
                 .scrollIndicators(.hidden)
             }
         }
-        .navigationBarTitleDisplayMode(.inline).toolbar(.hidden, for: .tabBar)
+        .navigationBarTitleDisplayMode(.inline).animatedTabBarHide()
         .toolbarBackground(.hidden, for: .navigationBar)
         .task { await viewModel.loadDueCards() }
         .overlay {