正文

JavaScript判断是否在当前标签页

不支持 IE 浏览器

//判断是否在当前标签页
let hidden, state, visibilityChange;
if (typeof document.hidden !== "undefined") {
  hidden = "hidden";
  visibilityChange = "visibilitychange";
  state = "visibilityState";
} else if (typeof document.mozHidden !== "undefined") {
  hidden = "mozHidden";
  visibilityChange = "mozvisibilitychange";
  state = "mozVisibilityState";
} else if (typeof document.msHidden !== "undefined") {
  hidden = "msHidden";
  visibilityChange = "msvisibilitychange";
  state = "msVisibilityState";
} else if (typeof document.webkitHidden !== "undefined") {
  hidden = "webkitHidden";
  visibilityChange = "webkitvisibilitychange";
  state = "webkitVisibilityState";
}
// 添加监听器，在title里显示状态变化
document.addEventListener(
  visibilityChange,
  function() {
    if (document[state] === "visible") {
      document.title = "回来啦！";
    } else {
      document.title = "去哪了？";
    }
  },
  false
);
//初始化页面状态
document.title = "回来啦！";