我尝试按照“ Web 版 Facebook 登录入门”中概述的步骤进行操作，但它们似乎不起作用。
我已按照此页面上的步骤操作；我检索了我的 App ID（第 1 步），我添加了 Facebook SDK for Javascript（第 2 步）（减去我在文档其他地方阅读的频道 URL 是可选的，因为我正在离线处理此页面而不是托管在服务器），然后我添加了登录代码（第 3 步）。
我不确定为什么它不起作用。我在控制台日志中收到错误“加载资源失败”。
完整代码：
<html>
<head></head>
<body>
<div id="fb-root"></div>
<script>
window.fbAsyncInit = function() {
FB.init({
appId : '1233456789', // App ID
//channelUrl : '//WWW.YOUR_DOMAIN.COM/channel.html', // Channel File
status : true, // check login status
cookie : true, // enable cookies to allow the server to access the session
xfbml : true // parse XFBML
});
// Here we subscribe to the auth.authResponseChange JavaScript event. This event is fired
// for any auth related change, such as login, logout or session refresh. This means that
// whenever someone who was previously logged out tries to log in again, the correct case below
// will be handled.
FB.Event.subscribe('auth.authResponseChange', function(response) {
// Here we specify what we do with the response anytime this event occurs.
if (response.status === 'connected') {
// The response object is returned with a status field that lets the app know the current
// login status of the person. In this case, we're handling the situation where they
// have logged in to the app.
testAPI();
} else if (response.status === 'not_authorized') {
// In this case, the person is logged into Facebook, but not into the app, so we call
// FB.login() to prompt them to do so.
// In real-life usage, you wouldn't want to immediately prompt someone to login
// like this, for two reasons:
// (1) JavaScript created popup windows are blocked by most browsers unless they
// result from direct user interaction (such as a mouse click)
// (2) it is a bad experience to be continually prompted to login upon page load.
FB.login();
} else {
// In this case, the person is not logged into Facebook, so we call the login()
// function to prompt them to do so. Note that at this stage there is no indication
// of whether they are logged into the app. If they aren't then they'll see the Login
// dialog right after they log in to Facebook.
// The same caveats as above apply to the FB.login() call here.
FB.login();
}
});
};
// Load the SDK asynchronously
(function(d){
var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0];
if (d.getElementById(id)) {return;}
js = d.createElement('script'); js.id = id; js.async = true;
js.src = "//connect.facebook.net/en_US/all.js";
ref.parentNode.insertBefore(js, ref);
}(document));
// Here we run a very simple test of the Graph API after login is successful.
// This testAPI() function is only called in those cases.
function testAPI() {
console.log('Welcome! Fetching your information.... ');
FB.api('/me', function(response) {
console.log('Good to see you, ' + response.name + '.');
});
}
</script>
<!--Below we include the Login Button social plugin. This button uses the JavaScript SDK to-->
<!--present a graphical Login button that triggers the FB.login() function when clicked.-->
<fb:login-button show-faces="true" width="200" max-rows="1"></fb:login-button>
</body>
</html>