javascript - '未捕获类型错误 : Illegal invocation' when trying to support cross browser prefixes in clojurescript

Question

getUserMedia 有许多在许多浏览器中仍然需要的前缀。我试图通过将所有前缀放在 getUserMedia 中来隐藏这些前缀的使用。

(def getUserMedia
  (or js/navigator.getUserMedia
      js/navigator.webkitGetUserMedia
      js/navigator.mozGetUserMedia
      js/navigator.msGetUserMedia))

(defn start-fx [app]
  (if getUserMedia
    (getUserMedia 
     ;; WORKS IF I REPLACE THE ABOVE getUserMedia WITH
     ;; js/navigator.webkitGetUserMedia USING CHROME BROWSER
     #js {:video true :audio true}
     #(om/update! app :record-src (.createObjectURL js/window.URL %))
     #(throw %))
    (js/alert "This browser does not support video recording!")))

然后当我尝试从 start-fx 调用它时，我在调用 getUserMedia 时得到了一个 Uncaught TypeError: Illegal invocation。我应该怎么做才能让我的代码跨浏览器兼容？

Answer 1

getUserMedia 必须绑定(bind)到 navigator 对象。等效的 JavaScript 是这样的:

var getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia ||
                   navigator.mozGetUserMedia || msGetUserMedia;
if (getUserMedia) {
  getUserMedia = getUserMedia.bind(navigator);
}