feat:优化沉浸式视频频道滑动切换

@@ -365,8 +365,8 @@ export struct VideoChannelPage {
     .displayCount(1, true)
     .alignSelf(ItemAlign.Start)
     .effectMode(EdgeEffect.None)
-    .onChange((index: number) => {
-      this.currentTopNavSelectedIndex = index
+    .onAnimationStart((index: number,targetindex:number) => {
+      this.currentTopNavSelectedIndex = targetindex
     })
   }
 }
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