为什么我在 airconsole-1.4.0.js:669 得到 "Uncaught TypeError"？

Question

我是 airconsole 的新手，我刚刚学习它，所以这可能是常态。我在 screen.html:

有这个

<html>
  <head>
    <script type="text/javascript" src="https://www.airconsole.com/api/airconsole-1.7.0.js"></script>
    <script type="text/javascript">
    var air_console = new AirConsole();

    // Listen for messages from other devices
    air_console.onMessage = function(from, data) {

      // We receive a message -> Send message back to the device
      air_console.message(from, "Full of pixels!");

      // Show message on device screen
      var info = document.createElement('DIV');
      info.innerHTML = data;
      document.body.appendChild(info);
    };
    </script>
    <style type="text/css">
      color: white;
    </style>
  </head>
  <body>

  </body>
</html>

我在 controller.html

中有这个

<html>
<head>
  <script type="text/javascript" src="https://www.airconsole.com/api/airconsole-1.7.0.js"></script>
  <script type="text/javascript">
    var air_console = new AirConsole();

    // Send a message to the screen
    air_console.message(AirConsole.SCREEN, "How are you?");

    // Listen for messages
    air_console.onMessage = function(from, data) {

      // Show message on device screen
      var info = document.createElement('DIV');
      info.innerHTML = data;
      document.body.appendChild(info);
    };
  </script>
    <style type="text/css">
      color: white;
    </style>
</head>
<body>

</body>
</html>

而且我在他们两个中都遇到了这个错误：

Uncaught TypeError: Cannot read property 'undefined' of undefined
    at AirConsole.onPostMessage_ (airconsole-1.7.0.js:1012)
    at airconsole-1.7.0.js:927

当然屏幕上什么也没有。我这里有什么错误，我该如何解决？

Answer 1

发送消息前需要等待onReady事件：

<html>
<head>
  <script type="text/javascript" src="https://www.airconsole.com/api/airconsole-1.7.0.js"></script>
  <script type="text/javascript">
    var air_console = new AirConsole();

    air_console.onReady = function() {
      // Send a message to the screen
      air_console.message(AirConsole.SCREEN, "How are you?");
    }

    // Listen for messages
    air_console.onMessage = function(from, data) {

      // Show message on device screen
      var info = document.createElement('DIV');
      info.innerHTML = data;
      document.body.appendChild(info);
    };
  </script>
    <style type="text/css">
      color: white;
    </style>
</head>
<body>

</body>
</html>

为什么我在 airconsole-1.4.0.js:669 得到 "Uncaught TypeError"？

Why I got "Uncaught TypeError" at airconsole-1.4.0.js:669?

html

javascript

airconsole