Screen.orientation
语法
var orientation = window.screen.orientation;
返回值
一个 ScreenOrientation (en-US) 的实例,表示屏幕的方向。
注意在更早的、有前缀的版本中会返回一个 DOMString 值,相当于 ScreenOrientation.type (en-US) 的值。
示例
js
var orientation = (screen.orientation || {}).type || screen.mozOrientation || screen.msOrientation;
if (orientation === "landscape-primary") {
  console.log("That looks good.");
} else if (orientation === "landscape-secondary") {
  console.log("Mmmh... the screen is upside down!");
} else if (orientation === "portrait-secondary" || orientation === "portrait-primary") {
  console.log("Mmmh... you should rotate your device to landscape");
} else if (orientation === undefined) {
  console.log("The orientation API isn't supported in this browser :(");
}
规范
| Specification | 
|---|
| Screen Orientation  # dom-screen-orientation  | 
浏览器兼容性
BCD tables only load in the browser