跨平台笔记应用的架构设计思考
妙墨是一款支持Mac、iPad、iPhone的跨平台Markdown笔记应用。在设计过程中,我们面临了跨平台数据同步、UI适配、性能优化等诸多挑战。今天来分享一些架构设计的思考和实践。
项目概述
妙墨的核心目标是:
- 提供一致的跨平台体验
- 实现实时数据同步
- 支持离线使用
- 保持高性能和流畅体验
整体架构设计
分层架构
┌─────────────────────────────────────┐
│ Presentation Layer │ ← SwiftUI (iOS/macOS)
├─────────────────────────────────────┤
│ Business Logic │ ← ViewModels + Services
├─────────────────────────────────────┤
│ Data Access Layer │ ← Core Data + CloudKit
├─────────────────────────────────────┤
│ Network Layer │ ← URLSession + WebSocket
└─────────────────────────────────────┘
技术选型
- UI框架: SwiftUI (统一代码库)
- 数据存储: Core Data + CloudKit
- 网络同步: CloudKit + WebSocket
- Markdown渲染: 自定义渲染引擎
- 文件管理: 本地文件系统 + iCloud
数据同步架构
1. CloudKit集成
使用CloudKit作为数据同步的核心:
class CloudKitManager: ObservableObject {
private let container = CKContainer.default()
private let privateDatabase: CKDatabase
init() {
privateDatabase = container.privateCloudDatabase
}
func syncNotes() async throws -> [Note] {
let query = CKQuery(recordType: "Note", predicate: NSPredicate(value: true))
let result = try await privateDatabase.records(matching: query)
return result.matchResults.compactMap { _, result in
switch result {
case .success(let record):
return Note(from: record)
case .failure:
return nil
}
}
}
}
2. 冲突解决策略
实现智能的冲突解决机制:
class ConflictResolver {
func resolveConflict(local: Note, remote: Note) -> Note {
// 基于修改时间的冲突解决
if local.modifiedAt > remote.modifiedAt {
return local
} else if remote.modifiedAt > local.modifiedAt {
return remote
} else {
// 时间相同时,合并内容
return mergeNotes(local: local, remote: remote)
}
}
private func mergeNotes(local: Note, remote: Note) -> Note {
let mergedContent = mergeContent(local.content, remote.content)
return Note(
id: local.id,
title: local.title,
content: mergedContent,
modifiedAt: Date()
)
}
}
3. 离线支持
实现完整的离线功能:
class OfflineManager {
private let localStore: LocalDataStore
private let syncQueue: OperationQueue
func saveNote(_ note: Note) {
// 立即保存到本地
localStore.save(note)
// 添加到同步队列
let syncOperation = SyncOperation(note: note)
syncQueue.addOperation(syncOperation)
}
func getOfflineNotes() -> [Note] {
return localStore.getAllNotes()
}
}
UI架构设计
1. 共享组件库
创建跨平台共享的UI组件:
// 跨平台文本编辑器
struct MarkdownEditor: View {
@Binding var content: String
@State private var isPreviewMode = false
var body: some View {
VStack {
if isPreviewMode {
MarkdownPreview(content: content)
} else {
TextEditor(text: $content)
.font(.custom("Monaco", size: 14))
}
Toggle("预览模式", isOn: $isPreviewMode)
}
}
}
// 跨平台工具栏
struct Toolbar: View {
let onSave: () -> Void
let onShare: () -> Void
var body: some View {
HStack {
Button("保存", action: onSave)
Spacer()
Button("分享", action: onShare)
}
.padding()
}
}
2. 响应式布局
适配不同设备的屏幕尺寸:
struct AdaptiveLayout: View {
@Environment(\.horizontalSizeClass) var sizeClass
var body: some View {
if sizeClass == .compact {
CompactLayout()
} else {
RegularLayout()
}
}
}
struct CompactLayout: View {
var body: some View {
NavigationView {
NoteList()
Text("选择笔记")
}
}
}
struct RegularLayout: View {
var body: some View {
NavigationSplitView {
NoteList()
} detail: {
NoteEditor()
}
}
}
性能优化
1. 懒加载策略
实现智能的内容加载:
class LazyContentLoader {
private let cache = NSCache<NSString, NSData>()
func loadNoteContent(id: String) async -> String {
// 检查缓存
if let cached = cache.object(forKey: id as NSString) {
return String(data: cached as Data, encoding: .utf8) ?? ""
}
// 异步加载
let content = await loadFromStorage(id: id)
// 更新缓存
if let data = content.data(using: .utf8) {
cache.setObject(data as NSData, forKey: id as NSString)
}
return content
}
}
2. 内存管理
优化内存使用:
class MemoryOptimizer {
private let maxCacheSize = 50 * 1024 * 1024 // 50MB
private var currentCacheSize = 0
func shouldLoadContent(_ note: Note) -> Bool {
// 基于内存使用情况决定是否加载内容
return currentCacheSize < maxCacheSize || note.isRecentlyAccessed
}
func cleanupCache() {
// 清理最久未访问的内容
cache.removeAllObjects()
currentCacheSize = 0
}
}
数据模型设计
1. Core Data模型
@Model
class Note {
var id: UUID
var title: String
var content: String
var createdAt: Date
var modifiedAt: Date
var isSynced: Bool
var cloudKitRecordID: String?
// 关系
var tags: [Tag]
var attachments: [Attachment]
init(title: String, content: String) {
self.id = UUID()
self.title = title
self.content = content
self.createdAt = Date()
self.modifiedAt = Date()
self.isSynced = false
self.tags = []
self.attachments = []
}
}
2. 数据迁移策略
class DataMigrationManager {
func migrateToNewVersion() async throws {
let migrationSteps = [
MigrationStep(from: 1, to: 2, migration: migrateV1ToV2),
MigrationStep(from: 2, to: 3, migration: migrateV2ToV3)
]
for step in migrationSteps {
try await step.migration()
}
}
private func migrateV1ToV2() async throws {
// 迁移逻辑
let notes = try await fetchV1Notes()
for note in notes {
let v2Note = convertToV2(note)
try await saveV2Note(v2Note)
}
}
}
测试策略
1. 单元测试
class NoteManagerTests: XCTestCase {
var noteManager: NoteManager!
override func setUp() {
noteManager = NoteManager()
}
func testCreateNote() async throws {
let note = try await noteManager.createNote(
title: "测试笔记",
content: "这是测试内容"
)
XCTAssertEqual(note.title, "测试笔记")
XCTAssertEqual(note.content, "这是测试内容")
}
func testSyncNotes() async throws {
let notes = try await noteManager.syncNotes()
XCTAssertFalse(notes.isEmpty)
}
}
2. UI测试
class MiaoMoUITests: XCTestCase {
func testCreateAndEditNote() {
let app = XCUIApplication()
app.launch()
// 创建新笔记
app.buttons["新建笔记"].tap()
let titleField = app.textFields["笔记标题"]
titleField.tap()
titleField.typeText("测试笔记")
let contentField = app.textViews["笔记内容"]
contentField.tap()
contentField.typeText("这是测试内容")
// 保存笔记
app.buttons["保存"].tap()
// 验证笔记已创建
XCTAssertTrue(app.staticTexts["测试笔记"].exists)
}
}
部署和分发
1. App Store Connect集成
// 自动化构建脚本
#!/bin/bash
# 构建iOS版本
xcodebuild -workspace MiaoMo.xcworkspace \
-scheme MiaoMo-iOS \
-configuration Release \
-destination generic/platform=iOS \
-archivePath MiaoMo-iOS.xcarchive \
archive
# 构建macOS版本
xcodebuild -workspace MiaoMo.xcworkspace \
-scheme MiaoMo-macOS \
-configuration Release \
-destination generic/platform=macOS \
-archivePath MiaoMo-macOS.xcarchive \
archive
2. 版本管理
struct VersionManager {
static let currentVersion = "2.1.0"
static func checkForUpdates() async -> UpdateInfo? {
let url = URL(string: "https://api.miaomo.app/version")!
let (data, _) = try await URLSession.shared.data(from: url)
let versionInfo = try JSONDecoder().decode(VersionInfo.self, from: data)
return versionInfo.isNewerThan(currentVersion) ? versionInfo : nil
}
}
总结
跨平台应用的开发需要综合考虑多个方面的挑战:
关键技术点
- 统一的数据模型:确保跨平台数据一致性
- 智能同步策略:处理网络延迟和冲突
- 响应式UI设计:适配不同设备和屏幕尺寸
- 性能优化:平衡功能和性能
- 测试策略:确保跨平台兼容性
最佳实践
- 使用SwiftUI实现代码复用
- 采用分层架构提高可维护性
- 实现完善的错误处理和用户反馈
- 建立持续集成和自动化测试
- 关注用户反馈和数据分析
跨平台开发虽然复杂,但通过合理的架构设计和最佳实践,可以创造出优秀的产品体验。希望这些经验对正在开发跨平台应用的朋友们有所帮助!