feat: update

dist/cjs/board/Whiteboard/index.js

         this.isFullscreen = false;
         this.pages = [];
         this.isInitialized = false;
+        this.isSyncing = false;
         this.visiblePageIndex = 0;
         if (target) {
             this.target = target;
     Whiteboard.prototype.onSnapshot = function (snap) {
         var _this = this;
         var id = snap.id, sources = snap.sources, pageIds = snap.pageIds, visiblePageIndex = snap.visiblePageIndex;
-        if (!this.isInitialized) {
+        if (!this.isInitialized && !this.isSyncing) {
             this.id = id;
             this.sources = sources;
-            this.initSiema();
+            this.isSyncing = true;
             this.sources.forEach(function (source, i) {
                 var page = new index_1.WhitePage({ imgSrc: source }, {
                     mode: _this.mode,
                 _this.pages.push(page);
                 page.open();
             });
+            this.initSiema();
         }
         this.isInitialized = true;
+        this.isSyncing = false;
         this.onPageChange(visiblePageIndex);
     };
     return Whiteboard;

dist/index.js

         this.isFullscreen = false;
         this.pages = [];
         this.isInitialized = false;
+        this.isSyncing = false;
         this.visiblePageIndex = 0;
         if (target) {
             this.target = target;
             sources = snap.sources,
             pageIds = snap.pageIds,
             visiblePageIndex = snap.visiblePageIndex;
-        if (!this.isInitialized) {
+        if (!this.isInitialized && !this.isSyncing) {
             this.id = id;
             this.sources = sources;
-            this.initSiema();
+            this.isSyncing = true;
             this.sources.forEach(function (source, i) {
                 var page = new index_1.WhitePage({ imgSrc: source }, {
                     mode: _this.mode,
                 _this.pages.push(page);
                 page.open();
             });
+            this.initSiema();
         }
         this.isInitialized = true;
+        this.isSyncing = false;
         this.onPageChange(visiblePageIndex);
     };
     return Whiteboard;

dist/types/board/Whiteboard/index.d.ts

     readonly activePage: WhitePage;
     siema: any;
     isInitialized: boolean;
+    isSyncing: boolean;
     visiblePageIndex: number;
     emitInterval: any;
     constructor(target: HTMLDivElement, { sources, eventHub, mode, visiblePageIndex }?: {

src/board/Whiteboard/index.ts

   /** State | 内部状态 */
   // 是否被初始化过，如果尚未被初始化，则等待来自于 Master 的同步消息
   isInitialized: boolean = false;
+  isSyncing: boolean = false;
   visiblePageIndex: number = 0;
   emitInterval: any;
 
   private onSnapshot(snap: SerializableWhiteboard) {
     const { id, sources, pageIds, visiblePageIndex } = snap;
 
-    if (!this.isInitialized) {
+    if (!this.isInitialized && !this.isSyncing) {
       this.id = id;
       this.sources = sources;
-      this.initSiema();
+      this.isSyncing = true;
 
       // 初始化所有的 WhitePages
       this.sources.forEach((source, i) => {
 
         page.open();
       });
+
+      this.initSiema();
     }
 
     this.isInitialized = true;
+    this.isSyncing = false;
     this.onPageChange(visiblePageIndex);
   }
 }