diff --git a/cocoscreator_projects/YouleNexus/assets/framework/core/frame-file-name.ts b/cocoscreator_projects/YouleNexus/assets/framework/core/frame-file-name.ts
new file mode 100644
index 0000000..a725540
--- /dev/null
+++ b/cocoscreator_projects/YouleNexus/assets/framework/core/frame-file-name.ts
@@ -0,0 +1,19 @@
+/**
+ * 帧文件名公式：与 scripts/ui-migration/frames.mjs:frameFileName 逐字对齐。
+ * 命名：B §3.4 + A §3.2 — 1 基 + 补零，保证字典序 = 帧序。
+ * FrameIndex=0 按 1 处理（旧引擎 2 个对象如此）。
+ *
+ * @param prefix 中间描述 frameSet.prefix，如 'atlas-login/00014'
+ * @param frameIndex 1 基帧号；0 按 1 处理
+ * @param count 该图总帧数（=中间描述 frameSet.count）
+ */
+export function frameFileName(prefix: string, frameIndex: number, count: number): string {
+  if (count <= 1) return `${prefix}.png`;
+  const n = String(frameIndex || 1).padStart(padWidth(count), '0');
+  return `${prefix}_${n}.png`;
+}
+
+/** 补零位数：保证字典序 = 帧序。 */
+export function padWidth(count: number): number {
+  return String(count).length;
+}
\ No newline at end of file
diff --git a/cocoscreator_projects/YouleNexus/assets/framework/ui/frame-set.ts b/cocoscreator_projects/YouleNexus/assets/framework/ui/frame-set.ts
new file mode 100644
index 0000000..f92e970
--- /dev/null
+++ b/cocoscreator_projects/YouleNexus/assets/framework/ui/frame-set.ts
@@ -0,0 +1,91 @@
+import { frameFileName } from '../core/frame-file-name.ts';
+
+/**
+ * 帧源抽象。生产实现从 Resources/Auto Atlas 加载；测试可注入 mock。
+ * 设计动机：FrameSet 组件不应直接 import Cocos 类型，保持逻辑层可单测。
+ */
+export interface FrameSource {
+  /**
+   * 按中间描述的 prefix 加载该 prefix 的全部帧。
+   * 例：loadByPrefix('atlas-login/00014') → SpriteFrame[12]
+   * @throws 若 prefix 不存在或加载失败，由实现决定（建议显式抛错）
+   */
+  loadByPrefix(prefix: string): Promise<unknown[]>;
+}
+
+/**
+ * 帧目标抽象。生产实现是一个薄壳包 Sprite.spriteFrame 赋值；
+ * 抽象出来让 FrameSet 不依赖 Sprite 类型。
+ */
+export interface FrameTarget {
+  setSpriteFrame(frame: unknown): void;
+}
+
+/**
+ * FrameSet：多帧图切帧组件（B §3.4）。
+ *
+ * 承载 set_self(spid, 43, n) 的 1773 处 C 移植调用。
+ * - 帧号 1 基（B §3 cpid=43）
+ * - FrameIndex=0 按 1 处理（旧引擎 2 个对象如此，frames.mjs:frameRect 实证）
+ * - 越界显式抛错（第二准则：不兜底）
+ * - 并发去重：多次 setFrame 在加载未完成时只触发一次 loadByPrefix
+ */
+export class FrameSet {
+  private state: 'idle' | 'loading' | 'ready' = 'idle';
+  private frames: unknown[] = [];
+  private loadingPromise: Promise<unknown[]> | null = null;
+  /** 当前帧（1 基）。0 = 尚未切过。 */
+  currentFrame: number = 0;
+
+  constructor(private readonly opts: { prefix: string; source: FrameSource; target: FrameTarget }) {}
+
+  /**
+   * 切到指定帧（1 基；0 按 1 处理）。
+   * @throws 帧号越界或 prefix 无帧时显式抛错（不静默兜底）
+   */
+  async setFrame(n: number): Promise<void> {
+    const frames = await this.ensureLoaded();
+    const idx = (n || 1) - 1; // 0 → 1；1 基
+    if (idx < 0 || idx >= frames.length) {
+      throw new RangeError(
+        `FrameSet 帧号越界: prefix=${this.opts.prefix} frameIndex=${n}（有效范围 1..${frames.length}）`,
+      );
+    }
+    this.opts.target.setSpriteFrame(frames[idx]);
+    this.currentFrame = n || 1;
+  }
+
+  private ensureLoaded(): Promise<unknown[]> {
+    if (this.state === 'ready') return Promise.resolve(this.frames);
+    if (this.loadingPromise) return this.loadingPromise;
+    this.state = 'loading';
+    this.loadingPromise = this.opts.source.loadByPrefix(this.opts.prefix).then(
+      (frames) => {
+        if (frames.length === 0) {
+          throw new Error(
+            `FrameSet prefix 无帧: ${this.opts.prefix}（检查 frameSet.count 与图集是否一致）`,
+          );
+        }
+        this.frames = frames;
+        this.state = 'ready';
+        this.loadingPromise = null;
+        return frames;
+      },
+      (err) => {
+        // 加载失败：重置状态以便重试
+        this.state = 'idle';
+        this.loadingPromise = null;
+        throw err;
+      },
+    );
+    return this.loadingPromise;
+  }
+
+  /** 仅用于测试断言状态。 */
+  get debugState(): 'idle' | 'loading' | 'ready' {
+    return this.state;
+  }
+}
+
+// 重新导出便于消费方一行 import
+export { frameFileName };
\ No newline at end of file
diff --git a/cocoscreator_projects/YouleNexus/assets/framework/ui/resources-frame-source.ts b/cocoscreator_projects/YouleNexus/assets/framework/ui/resources-frame-source.ts
new file mode 100644
index 0000000..3e1e7c8
--- /dev/null
+++ b/cocoscreator_projects/YouleNexus/assets/framework/ui/resources-frame-source.ts
@@ -0,0 +1,72 @@
+import { SpriteFrame, resources } from 'cc';
+import type { FrameSource } from './frame-set.ts';
+
+/**
+ * 生产 FrameSource：从 Resources/Auto Atlas 加载某目录的全部 SpriteFrame，按 prefix 过滤。
+ *
+ * 设计动机（详见 2026-08-27-ui-asset-and-skin-design.md）：
+ *   - 散图落 assets/framework/ui/atlas-{bucket}/，构建期由 Auto Atlas 打包成图集
+ *   - 运行时单张 .png 不可 Resources.load（合图后原文件被替换）
+ *   - 必须 loadDir 整个目录拿 SpriteFrame 列表，再按 prefix 过滤
+ *
+ * 调用方先按 spid → intermediate frameSet.prefix（'atlas-login/00014'）确定加载哪个目录
+ * —— 我们把目录从 prefix 第一段取出（'atlas-login'），加载后按 '00014_' 前缀过滤。
+ */
+export class ResourcesFrameSource implements FrameSource {
+  /**
+   * 简单 LRU：避免重复 loadDir 已加载过的目录。
+   * key = bucket 目录名（如 'atlas-login'）
+   */
+  private cache = new Map<string, SpriteFrame[]>();
+
+  async loadByPrefix(prefix: string): Promise<unknown[]> {
+    const slash = prefix.indexOf('/');
+    if (slash < 0) {
+      throw new Error(`FrameSet prefix 必须含 bucket 段: '${prefix}'（如 'atlas-login/00014'）`);
+    }
+    const bucket = prefix.slice(0, slash);
+    const filePrefix = prefix.slice(slash + 1); // '00014'
+
+    let frames = this.cache.get(bucket);
+    if (!frames) {
+      frames = await new Promise<SpriteFrame[]>((resolve, reject) => {
+        resources.loadDir(bucket, SpriteFrame, (err, list) => {
+          if (err) reject(err);
+          else resolve(list ?? []);
+        });
+      });
+      this.cache.set(bucket, frames);
+    }
+    // 按 name === '<filePrefix>_NN.png' 过滤并按 NN 升序
+    const matched: SpriteFrame[] = [];
+    const re = new RegExp(`^${escapeRe(filePrefix)}_(\\d+)\\.png$`);
+    for (const f of frames) {
+      const m = (f.name ?? '').match(re);
+      if (m) matched.push(f);
+    }
+    matched.sort((a, b) => {
+      const na = Number((a.name ?? '').match(re)![1]);
+      const nb = Number((b.name ?? '').match(re)![1]);
+      return na - nb;
+    });
+    return matched;
+  }
+}
+
+function escapeRe(s: string): string {
+  return s.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+}
+
+/**
+ * 生产 FrameTarget：把 spriteFrame 写到传入的 Sprite 组件。
+ * 把它做成工厂返回闭包，避免 FrameSet 直接 import Sprite 类型。
+ */
+export function makeSpriteTarget(sprite: { spriteFrame: unknown }): {
+  setSpriteFrame: (frame: unknown) => void;
+} {
+  return {
+    setSpriteFrame(frame) {
+      sprite.spriteFrame = frame as never;
+    },
+  };
+}
\ No newline at end of file
diff --git a/cocoscreator_projects/framework-tests/ui/frame-file-name.test.ts b/cocoscreator_projects/framework-tests/ui/frame-file-name.test.ts
new file mode 100644
index 0000000..02b326f
--- /dev/null
+++ b/cocoscreator_projects/framework-tests/ui/frame-file-name.test.ts
@@ -0,0 +1,25 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { frameFileName, padWidth } from '../../YouleNexus/assets/framework/core/frame-file-name.ts';
+
+test('padWidth: 9帧→1位，12帧→2位，100帧→3位', () => {
+  assert.equal(padWidth(9), 1);
+  assert.equal(padWidth(12), 2);
+  assert.equal(padWidth(100), 3);
+  assert.equal(padWidth(1), 1);
+});
+
+test('frameFileName: 1基+补零，字典序 = 帧序', () => {
+  assert.equal(frameFileName('atlas-login/00014', 1, 12), 'atlas-login/00014_01.png');
+  assert.equal(frameFileName('atlas-login/00014', 10, 12), 'atlas-login/00014_10.png');
+  const names = [frameFileName('atlas-login/00014', 2, 12), frameFileName('atlas-login/00014', 10, 12)];
+  assert.deepEqual([...names].sort(), ['atlas-login/00014_02.png', 'atlas-login/00014_10.png']);
+});
+
+test('frameFileName: FrameIndex=0 按 1 处理（旧引擎 2 个对象如此）', () => {
+  assert.equal(frameFileName('atlas-login/00014', 0, 12), 'atlas-login/00014_01.png');
+});
+
+test('frameFileName: 单帧图(prefix 不带下划线)直接拼接 .png', () => {
+  assert.equal(frameFileName('atlas-login/00019', 1, 1), 'atlas-login/00019.png');
+});
\ No newline at end of file
diff --git a/cocoscreator_projects/framework-tests/ui/frame-set.test.ts b/cocoscreator_projects/framework-tests/ui/frame-set.test.ts
new file mode 100644
index 0000000..d8b7cff
--- /dev/null
+++ b/cocoscreator_projects/framework-tests/ui/frame-set.test.ts
@@ -0,0 +1,128 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { FrameSet, type FrameSource, type FrameTarget } from '../../YouleNexus/assets/framework/ui/frame-set.ts';
+
+/**
+ * Mock FrameSource：按 prefix 返回 SpriteFrame 数组。
+ * SpriteFrame 是 opaque（任何非 null 对象即可，FrameSet 只引用不深查）。
+ */
+function makeFrames(prefix: string, count: number): any[] {
+  return Array.from({ length: count }, (_, i) => ({ __mock: true, name: frameName(prefix, i + 1, count) }));
+}
+function frameName(prefix: string, i: number, count: number): string {
+  return count <= 1 ? `${prefix}.png` : `${prefix}_${String(i).padStart(String(count).length, '0')}.png`;
+}
+
+/** Mock 加载器：同步、按 prefix 全量返回该 prefix 的所有帧。 */
+function mockSource(frames: Map<string, any[]>): FrameSource {
+  return {
+    async loadByPrefix(prefix: string) {
+      return frames.get(prefix) ?? [];
+    },
+  };
+}
+
+/** Mock 目标：仅记录最后一次 setFrame 调用。 */
+function mockTarget(): FrameTarget & { lastFrame: any | null; lastError: Error | null } {
+  return { lastFrame: null, lastError: null, setSpriteFrame(f) { this.lastFrame = f; } };
+}
+
+test('FrameSet 首次 setFrame 触发按 prefix 加载', async () => {
+  const frames = makeFrames('atlas-login/00014', 12);
+  const source = mockSource(new Map([['atlas-login/00014', frames]]));
+  const set = new FrameSet({ prefix: 'atlas-login/00014', source, target: mockTarget() });
+
+  const before = (set as any).state;
+  assert.equal(before, 'idle');
+
+  await set.setFrame(1);
+  assert.equal((set as any).state, 'ready');
+});
+
+test('FrameSet setFrame(1) 返回第一帧（与 frameFileName 公式对齐）', async () => {
+  const frames = makeFrames('atlas-login/00014', 12);
+  const source = mockSource(new Map([['atlas-login/00014', frames]]));
+  const target = mockTarget();
+  const set = new FrameSet({ prefix: 'atlas-login/00014', source, target });
+
+  await set.setFrame(1);
+  assert.equal(target.lastFrame?.name, 'atlas-login/00014_01.png');
+});
+
+test('FrameSet setFrame(10) 返回第 10 帧（旧引擎实证：通知=FrameIndex=10）', async () => {
+  const frames = makeFrames('atlas-login/00014', 12);
+  const source = mockSource(new Map([['atlas-login/00014', frames]]));
+  const target = mockTarget();
+  const set = new FrameSet({ prefix: 'atlas-login/00014', source, target });
+
+  await set.setFrame(10);
+  assert.equal(target.lastFrame?.name, 'atlas-login/00014_10.png');
+});
+
+test('FrameSet setFrame(0) 按 1 处理（旧引擎 2 个对象 FrameIndex=0）', async () => {
+  const frames = makeFrames('atlas-login/00014', 12);
+  const source = mockSource(new Map([['atlas-login/00014', frames]]));
+  const target = mockTarget();
+  const set = new FrameSet({ prefix: 'atlas-login/00014', source, target });
+
+  await set.setFrame(0);
+  assert.equal(target.lastFrame?.name, 'atlas-login/00014_01.png');
+});
+
+test('FrameSet 越界帧号显式抛错（第二准则：不兜底）', async () => {
+  const frames = makeFrames('atlas-login/00014', 12);
+  const source = mockSource(new Map([['atlas-login/00014', frames]]));
+  const set = new FrameSet({ prefix: 'atlas-login/00014', source, target: mockTarget() });
+  await set.setFrame(1); // 先把 state 推到 ready
+
+  await assert.rejects(() => set.setFrame(13), (e: Error) => {
+    return e.message.includes('atlas-login/00014') && e.message.includes('13');
+  });
+});
+
+test('FrameSet 源返回空数组显式抛错（prefix 错配要早暴露）', async () => {
+  const source = mockSource(new Map()); // 空
+  const set = new FrameSet({ prefix: 'atlas-login/wrong', source, target: mockTarget() });
+  await assert.rejects(() => set.setFrame(1), (e: Error) => e.message.includes('atlas-login/wrong'));
+});
+
+test('FrameSet 不重复 IO：连续 setFrame 只 loadByPrefix 一次', async () => {
+  const frames = makeFrames('atlas-login/00014', 12);
+  let calls = 0;
+  const source: FrameSource = {
+    async loadByPrefix(prefix: string) {
+      calls++;
+      return frames;
+    },
+  };
+  const target = mockTarget();
+  const set = new FrameSet({ prefix: 'atlas-login/00014', source, target });
+
+  await set.setFrame(1);
+  await set.setFrame(5);
+  await set.setFrame(10);
+  assert.equal(calls, 1, '只首次触发加载');
+});
+
+test('FrameSet 并发去重：两次 setFrame(1) 同时调用也只 loadByPrefix 一次', async () => {
+  const frames = makeFrames('atlas-login/00014', 12);
+  let calls = 0;
+  const source: FrameSource = {
+    async loadByPrefix(prefix: string) {
+      calls++;
+      // 模拟异步：制造竞态
+      await new Promise((r) => setTimeout(r, 5));
+      return frames;
+    },
+  };
+  const target = mockTarget();
+  const set = new FrameSet({ prefix: 'atlas-login/00014', source, target });
+
+  await Promise.all([set.setFrame(1), set.setFrame(1), set.setFrame(1)]);
+  assert.equal(calls, 1);
+});
+
+test('FrameSet currentFrame 默认 0（与 B §3 cpid=43 初始一致）', () => {
+  const set = new FrameSet({ prefix: 'atlas-login/00014', source: mockSource(new Map()), target: mockTarget() });
+  assert.equal(set.currentFrame, 0);
+});
\ No newline at end of file
diff --git a/cocoscreator_projects/tsconfig.framework.json b/cocoscreator_projects/tsconfig.framework.json
index 650a657..a37a3a2 100644
--- a/cocoscreator_projects/tsconfig.framework.json
+++ b/cocoscreator_projects/tsconfig.framework.json
@@ -13,5 +13,8 @@
   "include": [
     "YouleNexus/assets/framework/**/*.ts",
     "framework-tests/**/*.ts"
+  ],
+  "exclude": [
+    "YouleNexus/assets/framework/ui/resources-frame-source.ts"
   ]
 }