diff --git a/docs/Development-Plan.md b/docs/Development-Plan.md
index 28fa378..2995a43 100644
--- a/docs/Development-Plan.md
+++ b/docs/Development-Plan.md
@@ -479,12 +479,13 @@ Contract       Design          Plan（本文档）
 - [ ] **4.1** `Vendor/WechatSDK/` 拷贝微信 SDK
   - Info.plist 加 URL Scheme（`wx586a9b321e56efb7`）+ `LSApplicationQueriesSchemes`（`weixin` / `weixinULAPI` / `weixinURLParamsAPI`）
   - Entitlement 加 Associated Domains（Universal Links）
-- [ ] **4.2** **SharePanel 三选一面板（msext gameController.m:585 等价行为）**
-  - **关键发现**：msext `gameController.m:575-597` 表明 H5 调 `friendsShare` 时：
-    - `sharefriend == 1`（好友/私聊）→ 弹 **SharePanel 三选一面板**（微信好友 + QQ + 抖音）
-    - `sharefriend == 2`（朋友圈）→ 直接 `WechatShareManager.shareWithContent`（朋友圈）
-  - Contract §3.1 ［2］旧描述（sharetype=3 闲聊）已被 msext 新代码覆盖；`sharetype` 字段在新代码里读了但不用
-  - 新外壳按 SharePanel 模式实现，不依赖 Contract 旧描述
+- [x] **4.2** **SharePanel 三选一面板 + SharePlatform 框架**（4.B 完成）
+  - `Source/Share/SharePlatform.swift`：SharePlatform 协议（name / isInstalled / share async）+ ShareContent struct（nonisolated Sendable）+ ShareResult enum（success / cancelled / notInstalled / failed）+ ShareScene enum（friend / timeline）
+  - `Source/Share/SharePanel.swift`：底部弹出三按钮（微信 / QQ / 抖音）+ 半透明背景点击关闭 + 0.25s 滑入/滑出动画；与 msext SharePanel.m 等价行为
+  - `Source/Share/ShareCenter.swift`：sharefriend == "1" 弹 SharePanel；"2" 直接 WechatShare.timeline；与 msext gameController.m:585 行为 1:1
+  - `Source/Share/{Wechat,QQ,Douyin}Share.swift`：三个平台 stub（仅返回 success），Phase 4.C/4.D/4.E 升级
+  - `FriendsShareHandler` 升级：调 ShareCenter.dispatch + 完成后触发 sharesuccess 反向 callback（success/cancelled 都发，notInstalled/failed 不发，沿用 msext 乐观策略）
+  - BuildProject 通过
 - [ ] **4.3** **QQ 分享走 URL Scheme，不依赖 SDK**
   - 移植 msext `QQShareManager.m:716-771` `simpleShareToQQFriend` 简化版
   - URL 构造：`mqqapi://share/to_fri?version=1&cflag=0&req_type=1&url=...&title=...&description=...`
diff --git a/ylgamehall/Source/Bridge/Handlers/FriendsShareHandler.swift b/ylgamehall/Source/Bridge/Handlers/FriendsShareHandler.swift
index 0b72a1d..87a1d87 100644
--- a/ylgamehall/Source/Bridge/Handlers/FriendsShareHandler.swift
+++ b/ylgamehall/Source/Bridge/Handlers/FriendsShareHandler.swift
@@ -2,37 +2,63 @@
 //  FriendsShareHandler.swift
 //  ylgamehall
 //
-//  H5 → Native handler stub：friendsSharetypeUrlToptitleDescript — 分享
+//  H5 → Native handler：friendsSharetypeUrlToptitleDescript — 分享
 //  契约：docs/H5-Native-Contract.md §3.1 ［2］ + §3.2 ［11］sharesuccess
 //
-//  Phase 4.A 阶段为 stub（仅 cb 维持契约）；Phase 4.B 微信 SDK 接入 + Phase 4.C
-//  QQ URL Scheme 完整实现后升级。
-//
-//  完整实现：
-//    1. 入参解析：sharefriend (1=好友 / 2=朋友圈) + sharetype (1=微信 / 2=微信 /
-//       3=闲聊；契约 §3.1 ［2］) + type (1=链接 / 2=截图 / 3=远端图) + url +
-//       title + description
-//    2. ShareCenter.dispatch(req)：
-//       - sharetype = 3 → 闲聊 NoopSharePlatform（暂未集成）
-//       - 否则 → WeChatShare（Phase 4.B SDK 接入）
+//  完整流程（与 msext gameController.m:575-597 等价）：
+//    1. 入参解析 ShareContent
+//    2. ShareCenter.dispatch：
+//       - sharefriend == "1" → SharePanel 三选一（微信好友 / QQ / 抖音）
+//       - sharefriend == "2" → 直接 WechatShare 朋友圈
 //    3. 分享完成 → bridge.call("sharesuccess", { success: "2", type: <sharefriend 原值> })
 //
-//  ⚠️ QQ 分享按用户约定**不依赖 SDK**，走 URL Scheme（mqq://share/to_fri、
-//     mqqapi://share/to_qzone 等）；参 daoqi/msext QQShareManager.m fallback
-//     部分（Phase 4.C 真实落地）
+//  各平台 SDK 依赖：
+//    - 微信：Phase 4.E 接入项目方 SDK（当前 WechatShare 是 stub）
+//    - QQ + 抖音：不依赖 SDK，走 URL Scheme（Phase 4.C/4.D 真实落地，当前 stub）
 //
 
 import Foundation
 
+@MainActor
 public enum FriendsShareHandler {
 
     public static func register(on bridge: any BridgeProtocol) {
         // 【2】friendsSharetypeUrlToptitleDescript
-        //   入参：sharefriend / sharetype / type / url / title / description
+        //   入参：sharefriend / sharetype / type / webpageUrl / title / description
         //   cb: "sharefriend"（msext 字面，沿用）
-        //   完整实现需触发 sharesuccess 反向 callback（Phase 4.B/4.C）
-        bridge.register("friendsSharetypeUrlToptitleDescript") { _, callback in
+        //   反向 callback：sharesuccess({ success: "2", type: sharefriend 原值 })
+        bridge.register("friendsSharetypeUrlToptitleDescript") { [weak bridge] data, callback in
             callback?(.string("sharefriend"))
+
+            guard let obj = data?.asObject else { return }
+            let content = ShareContent(
+                sharefriend: obj["sharefriend"]?.asString ?? "1",
+                sharetype:   obj["sharetype"]?.asString ?? "",
+                type:        obj["type"]?.asString ?? "1",
+                webpageUrl:  obj["webpageUrl"]?.asString ?? "",
+                title:       obj["title"]?.asString ?? "",
+                desc:        obj["description"]?.asString ?? ""
+            )
+            let sharefriend = content.sharefriend
+
+            await MainActor.run {
+                ShareCenter.dispatch(content) { result in
+                    // success / cancelled / notInstalled / failed — msext 行为：
+                    // 只要不是明确失败就发 sharesuccess（乐观策略，URL Scheme 无返回）
+                    switch result {
+                    case .success, .cancelled:
+                        bridge?.call("sharesuccess",
+                                     data: .object([
+                                         "success": .string("2"),
+                                         "type":    .string(sharefriend)
+                                     ]),
+                                     callback: nil)
+                    case .notInstalled, .failed:
+                        // 不发 sharesuccess（H5 业务期 timeout 后自行 fallback）
+                        break
+                    }
+                }
+            }
         }
     }
 }
diff --git a/ylgamehall/Source/Share/DouyinShare.swift b/ylgamehall/Source/Share/DouyinShare.swift
new file mode 100644
index 0000000..36b41a9
--- /dev/null
+++ b/ylgamehall/Source/Share/DouyinShare.swift
@@ -0,0 +1,40 @@
+//
+//  DouyinShare.swift
+//  ylgamehall
+//
+//  抖音分享 SharePlatform 实现 stub（Phase 4.D 真实落地）。
+//
+//  Phase 4.B 阶段为 stub（仅返回 success）；
+//  Phase 4.D 移植 msext DouyinShareManager.m URL Scheme + Photos 路径
+//  （snssdk1128://share/video + 保存截图到相册让用户在抖音里选）。
+//
+
+import UIKit
+
+@MainActor
+public final class DouyinShare: SharePlatform {
+
+    public static let shared = DouyinShare()
+
+    public let name = "Douyin"
+
+    /// 检测抖音 app 是否安装：canOpenURL("snssdk1128://")
+    public var isInstalled: Bool {
+        guard let url = URL(string: "snssdk1128://") else { return false }
+        return UIApplication.shared.canOpenURL(url)
+    }
+
+    public init() {}
+
+    public func share(_ content: ShareContent, scene: ShareScene) async -> ShareResult {
+        guard isInstalled else { return .notInstalled(platform: name) }
+        // Phase 4.B 阶段 stub：返回 success，Phase 4.D 升级
+        // 真实实现（Phase 4.D）：
+        //   - type == 2 截图：UIGraphicsImageRenderer 截图 → 保存到相册（PHPhotoLibrary）
+        //   - type == 其他 远端图：URLSession 下载 → 保存到相册
+        //   - 保存后 snssdk1128://share/video 或 snssdk1128://camera 调起抖音
+        //   - Info.plist 加 NSPhotoLibraryAddUsageDescription
+        //   - 调起即视为 success
+        return .success
+    }
+}
diff --git a/ylgamehall/Source/Share/QQShare.swift b/ylgamehall/Source/Share/QQShare.swift
new file mode 100644
index 0000000..a70e612
--- /dev/null
+++ b/ylgamehall/Source/Share/QQShare.swift
@@ -0,0 +1,39 @@
+//
+//  QQShare.swift
+//  ylgamehall
+//
+//  QQ 分享 SharePlatform 实现 stub（Phase 4.C 真实落地）。
+//
+//  Phase 4.B 阶段为 stub（仅返回 success，让 SharePanel 流程跑通）；
+//  Phase 4.C 移植 msext QQShareManager.m:716-771 simpleShareToQQFriend
+//  的 URL Scheme fallback（mqqapi://share/to_fri?...）。
+//
+
+import UIKit
+
+@MainActor
+public final class QQShare: SharePlatform {
+
+    public static let shared = QQShare()
+
+    public let name = "QQ"
+
+    /// 检测 QQ app 是否安装：canOpenURL("mqqapi://")
+    public var isInstalled: Bool {
+        guard let url = URL(string: "mqqapi://") else { return false }
+        return UIApplication.shared.canOpenURL(url)
+    }
+
+    public init() {}
+
+    public func share(_ content: ShareContent, scene: ShareScene) async -> ShareResult {
+        guard isInstalled else { return .notInstalled(platform: name) }
+        // Phase 4.B 阶段 stub：返回 success，Phase 4.C 升级为完整 URL Scheme 调起
+        // 真实实现（Phase 4.C）：
+        //   - 拼装 mqqapi://share/to_fri?version=1&cflag=0&req_type=1
+        //     &url=...&title=...&description=...
+        //   - canOpenURL + open
+        //   - 调起即视为 success（URL Scheme 单向无返回，msext 同款乐观策略）
+        return .success
+    }
+}
diff --git a/ylgamehall/Source/Share/ShareCenter.swift b/ylgamehall/Source/Share/ShareCenter.swift
new file mode 100644
index 0000000..89ecc0e
--- /dev/null
+++ b/ylgamehall/Source/Share/ShareCenter.swift
@@ -0,0 +1,40 @@
+//
+//  ShareCenter.swift
+//  ylgamehall
+//
+//  H5 friendsShare 调用入口的协调中心，按 msext gameController.m:575-597 行为：
+//    - sharefriend == "1"（好友/私聊）→ 弹 SharePanel 三选一（微信/QQ/抖音）
+//    - sharefriend == "2"（朋友圈）   → 直接 WechatShare（朋友圈 timeline 场景）
+//
+//  与 Design §8.2 ShareKit 一致：策略模式 + SharePlatform 协议。
+//
+
+import Foundation
+
+@MainActor
+public enum ShareCenter {
+
+    /// 统一分发入口。由 FriendsShareHandler 在 handler 闭包内调用。
+    /// completion 在分享结果回来后触发；UI 期间 await 暂停闭包但 cb 已先返回（msext 行为）。
+    public static func dispatch(_ content: ShareContent, completion: @escaping (ShareResult) -> Void) {
+        switch content.sharefriend {
+        case "1":
+            // 好友/私聊 → SharePanel 三选一
+            SharePanel.show(content: content, completion: completion)
+
+        case "2":
+            // 朋友圈 → 直接 WechatShare（timeline 场景）
+            Task { @MainActor in
+                let result = await WechatShare.shared.share(content, scene: .timeline)
+                completion(result)
+            }
+
+        default:
+            // 未知 sharefriend：msext 沿用第二条分支兜底（朋友圈微信）
+            Task { @MainActor in
+                let result = await WechatShare.shared.share(content, scene: .timeline)
+                completion(result)
+            }
+        }
+    }
+}
diff --git a/ylgamehall/Source/Share/SharePanel.swift b/ylgamehall/Source/Share/SharePanel.swift
new file mode 100644
index 0000000..3ec1bbe
--- /dev/null
+++ b/ylgamehall/Source/Share/SharePanel.swift
@@ -0,0 +1,166 @@
+//
+//  SharePanel.swift
+//  ylgamehall
+//
+//  原生分享面板：底部弹出三选一（微信好友 / QQ / 抖音）。
+//
+//  与 msext SharePanel.m 等价行为：
+//    - 半透明黑底覆盖全屏，点击空白区关闭
+//    - 内容视图从屏幕底部滑入，0.25s 动画
+//    - 三个圆形按钮 + label，等间距居中布局
+//    - 点击按钮后先 dismiss 再触发对应 SharePlatform.share
+//
+//  Phase 4.B 阶段：UI 完整 + 调用 SharePlatform stub；
+//  Phase 4.C/4.D 阶段：SharePlatform 升级为真实 URL Scheme 实现，本类不变。
+//
+
+import UIKit
+import os.log
+
+@MainActor
+public final class SharePanel: UIView {
+
+    private static let log = Logger(subsystem: "ylgamehall", category: "SharePanel")
+
+    private static let panelHeight: CGFloat = 200
+    private static let buttonSize: CGFloat = 60
+    private static let animationDuration: TimeInterval = 0.25
+
+    private let content: ShareContent
+    private let completion: (ShareResult) -> Void
+
+    private let contentView = UIView()
+
+    public init(content: ShareContent, completion: @escaping (ShareResult) -> Void) {
+        self.content = content
+        self.completion = completion
+        super.init(frame: UIScreen.main.bounds)
+        backgroundColor = UIColor(white: 0, alpha: 0)
+        setupUI()
+    }
+
+    @available(*, unavailable)
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) is not supported")
+    }
+
+    // MARK: - 公共入口
+
+    /// 弹出分享面板。任何时候同一个面板只允许一个实例。
+    public static func show(content: ShareContent, completion: @escaping (ShareResult) -> Void) {
+        guard let window = topWindow() else {
+            completion(.failed(reason: "no key window"))
+            return
+        }
+        let panel = SharePanel(content: content, completion: completion)
+        window.addSubview(panel)
+        panel.animateIn()
+    }
+
+    private static func topWindow() -> UIWindow? {
+        UIApplication.shared.connectedScenes
+            .compactMap { $0 as? UIWindowScene }
+            .flatMap(\.windows)
+            .first { $0.isKeyWindow }
+    }
+
+    // MARK: - UI 装配
+
+    private func setupUI() {
+        // 半透明背景手势
+        let tap = UITapGestureRecognizer(target: self, action: #selector(handleBackgroundTap(_:)))
+        addGestureRecognizer(tap)
+
+        // 内容视图（屏幕底部，初始 Y 在屏幕外）
+        let screen = UIScreen.main.bounds
+        contentView.frame = CGRect(x: 0, y: screen.height, width: screen.width, height: Self.panelHeight)
+        contentView.backgroundColor = .white
+        let mask = CAShapeLayer()
+        mask.path = UIBezierPath(
+            roundedRect: contentView.bounds,
+            byRoundingCorners: [.topLeft, .topRight],
+            cornerRadii: CGSize(width: 10, height: 10)
+        ).cgPath
+        contentView.layer.mask = mask
+        addSubview(contentView)
+
+        // 三个按钮 + label 等间距居中布局
+        let buttonsContainer = UIView(frame: CGRect(x: 0, y: 30, width: screen.width, height: 110))
+        contentView.addSubview(buttonsContainer)
+
+        let buttons: [(title: String, platform: SharePlatform, color: UIColor)] = [
+            ("微信", WechatShare.shared, UIColor(red: 0.06, green: 0.69, blue: 0.36, alpha: 1)),
+            ("QQ",   QQShare.shared,     UIColor(red: 0.12, green: 0.51, blue: 0.97, alpha: 1)),
+            ("抖音", DouyinShare.shared, .black)
+        ]
+
+        let totalButtonsWidth = Self.buttonSize * CGFloat(buttons.count)
+        let spacing = (screen.width - totalButtonsWidth) / CGFloat(buttons.count + 1)
+        for (index, b) in buttons.enumerated() {
+            let x = spacing + CGFloat(index) * (Self.buttonSize + spacing)
+            let button = UIButton(type: .system)
+            button.frame = CGRect(x: x, y: 0, width: Self.buttonSize, height: Self.buttonSize)
+            button.backgroundColor = b.platform.isInstalled ? b.color : .lightGray
+            button.layer.cornerRadius = Self.buttonSize / 2
+            button.setTitle(b.title.prefix(1).description, for: .normal)
+            button.setTitleColor(.white, for: .normal)
+            button.titleLabel?.font = .systemFont(ofSize: 22, weight: .medium)
+            button.tag = index
+            button.addTarget(self, action: #selector(handleButtonTap(_:)), for: .touchUpInside)
+            buttonsContainer.addSubview(button)
+
+            let label = UILabel(frame: CGRect(x: x, y: Self.buttonSize + 8, width: Self.buttonSize, height: 20))
+            label.text = b.title
+            label.textAlignment = .center
+            label.font = .systemFont(ofSize: 13)
+            label.textColor = .darkGray
+            buttonsContainer.addSubview(label)
+        }
+    }
+
+    // MARK: - 动画
+
+    private func animateIn() {
+        UIView.animate(withDuration: Self.animationDuration) {
+            self.backgroundColor = UIColor(white: 0, alpha: 0.5)
+            var frame = self.contentView.frame
+            frame.origin.y = UIScreen.main.bounds.height - Self.panelHeight
+            self.contentView.frame = frame
+        }
+    }
+
+    private func dismiss(then action: (() -> Void)? = nil) {
+        UIView.animate(withDuration: Self.animationDuration, animations: {
+            self.backgroundColor = UIColor(white: 0, alpha: 0)
+            var frame = self.contentView.frame
+            frame.origin.y = UIScreen.main.bounds.height
+            self.contentView.frame = frame
+        }, completion: { _ in
+            self.removeFromSuperview()
+            action?()
+        })
+    }
+
+    // MARK: - 事件
+
+    @objc private func handleBackgroundTap(_ gesture: UITapGestureRecognizer) {
+        let point = gesture.location(in: self)
+        if !contentView.frame.contains(point) {
+            dismiss { [self] in completion(.cancelled) }
+        }
+    }
+
+    @objc private func handleButtonTap(_ sender: UIButton) {
+        let platforms: [SharePlatform] = [WechatShare.shared, QQShare.shared, DouyinShare.shared]
+        let platform = platforms[sender.tag]
+        let scene: ShareScene = content.sharefriend == "2" ? .timeline : .friend
+        let snapshotContent = content
+        dismiss {
+            Task { @MainActor in
+                let result = await platform.share(snapshotContent, scene: scene)
+                Self.log.debug("share via \(platform.name, privacy: .public) result=\(String(describing: result), privacy: .public)")
+                self.completion(result)
+            }
+        }
+    }
+}
diff --git a/ylgamehall/Source/Share/SharePlatform.swift b/ylgamehall/Source/Share/SharePlatform.swift
new file mode 100644
index 0000000..a7d1d1a
--- /dev/null
+++ b/ylgamehall/Source/Share/SharePlatform.swift
@@ -0,0 +1,70 @@
+//
+//  SharePlatform.swift
+//  ylgamehall
+//
+//  分享平台抽象 + ShareContent 数据载荷 + ShareResult。
+//
+//  策略模式：微信 / QQ / 抖音 各自实现 SharePlatform 协议，由 ShareCenter
+//  按 sharefriend / 用户选择分发。新增平台只加一个 conformance。
+//
+//  详见 docs/H5-Native-Implementation-Design.md §8.2 ShareKit。
+//
+
+import Foundation
+import UIKit
+
+/// 分享内容（H5 → Native 桥的 friendsShare 参数解析后的 Swift 类型）。
+/// 项目默认 SWIFT_DEFAULT_ACTOR_ISOLATION = MainActor 让 struct 也跨 actor 受限；
+/// 标 nonisolated 让 handler 闭包（@Sendable async）可自由构造与传递。
+nonisolated public struct ShareContent: Sendable {
+    /// 分享给好友（"1"）还是朋友圈（"2"）
+    public let sharefriend: String
+    /// msext 旧描述：1 微信 / 2 微信 / 3 闲聊。新代码读了但不用（SharePanel 由用户选平台决定）。
+    /// 保留字段以维持契约 §3.1 ［2］兼容性
+    public let sharetype: String
+    /// 1 链接 / 2 截图 / 其他=远端图 URL 分享
+    public let type: String
+    /// 链接 URL 或图片 URL
+    public let webpageUrl: String
+    public let title: String
+    public let desc: String
+
+    public init(
+        sharefriend: String,
+        sharetype: String,
+        type: String,
+        webpageUrl: String,
+        title: String,
+        desc: String
+    ) {
+        self.sharefriend = sharefriend
+        self.sharetype = sharetype
+        self.type = type
+        self.webpageUrl = webpageUrl
+        self.title = title
+        self.desc = desc
+    }
+}
+
+public enum ShareResult: Sendable {
+    case success
+    case cancelled
+    case notInstalled(platform: String)
+    case failed(reason: String)
+}
+
+/// 分享场景：好友 / 朋友圈（仅微信有意义；QQ / 抖音 暂不区分）。
+public enum ShareScene: Sendable {
+    case friend         // 微信好友 / QQ 好友
+    case timeline       // 微信朋友圈 / QQ 空间
+}
+
+@MainActor
+public protocol SharePlatform: AnyObject {
+    /// 平台唯一标识（用于 log / 错误提示）
+    var name: String { get }
+    /// 平台 app 是否已安装（用于 SharePanel 按钮置灰）
+    var isInstalled: Bool { get }
+    /// 执行分享（按 content.type 路由到链接 / 截图 / 远端图）
+    func share(_ content: ShareContent, scene: ShareScene) async -> ShareResult
+}
diff --git a/ylgamehall/Source/Share/WechatShare.swift b/ylgamehall/Source/Share/WechatShare.swift
new file mode 100644
index 0000000..87f00b9
--- /dev/null
+++ b/ylgamehall/Source/Share/WechatShare.swift
@@ -0,0 +1,31 @@
+//
+//  WechatShare.swift
+//  ylgamehall
+//
+//  微信分享 SharePlatform 实现 stub。
+//
+//  Phase 4.E 阶段为 stub（等项目方提供微信 SDK + AppID + Universal Links）；
+//  完整实现见 Design §8.2 ShareKit + §8.5 微信 / QQ 多发起方派发。
+//
+
+import Foundation
+
+@MainActor
+public final class WechatShare: SharePlatform {
+
+    public static let shared = WechatShare()
+
+    public let name = "WeChat"
+
+    /// Stub: 微信 SDK 未接入前永远返回 true，让 SharePanel 按钮可点；
+    /// 真实接入 SDK 后改为 `WXApi.isWXAppInstalled()`
+    public var isInstalled: Bool { true }
+
+    public init() {}
+
+    public func share(_ content: ShareContent, scene: ShareScene) async -> ShareResult {
+        // Phase 4.E 阶段 stub：仅返回 success，不真实调起微信
+        // 完整实现：WXApi.send + SendMessageToWXResp 回调 + 多发起方 state 配对
+        return .success
+    }
+}