<video
  height="150px"
  width="100%"
  controls
  :src="src"
  v-on:fullscreenchange="onFullscreenChange"
  v-on:webkitfullscreenchange="onFullscreenChange"
></video>

method里

methods: {
    onFullscreenChange() {
      if (document.fullscreenElement || document.webkitFullscreenElement) {
        // 全屏狀態(tài)
        console.log('Video is in fullscreen mode');
      } else {
        console.log('Video is not in fullscreen mode');
      }
    },
}

效果如下，在瀏覽器和webview里都有效

全屏效果.png