fix ios subtitle

docs/uncompiled/artplayer/index.js

@@ -3728,11 +3728,14 @@ class Subtitle extends (0, _componentDefault.default) {
         this.name = "subtitle";
         this.eventDestroy = ()=>null;
         this.init(art.option.subtitle);
-        art.on("fullscreen", (state)=>{
+        let lastState = false;
+        art.on("video:timeupdate", ()=>{
             if (!this.url) return;
-            const { $video  } = this.art.template;
-            if (state && $video.webkitDisplayingFullscreen) this.createTrack("subtitles", this.url);
-            else this.createTrack("metadata", this.url);
+            const state = this.art.template.$video.webkitDisplayingFullscreen;
+            if (state !== lastState) {
+                lastState = state;
+                this.createTrack(state ? "subtitles" : "metadata", this.url);
+            }
         });
     }
     get url() {