Facebook最近在处理会话重定向的方式上做出了改变。有关公告，请参阅本周Operation Developer Love博客文章中的“会话重定向行为的更改”。

对于那些正在寻找简单答案的人 加上这个，对我很管用

if (window.location.hash === "#_=_"){
    history.replaceState 
        ? history.replaceState(null, null, window.location.href.split("#")[0])
        : window.location.hash = "";
}

请查看Paul Schwarz的完整回答

https://stackoverflow.com/a/18305085/2694806

博士TL;

if (window.location.hash === "#_=_"){
    history.replaceState 
        ? history.replaceState(null, null, window.location.href.split("#")[0])
        : window.location.hash = "";
}

完整版本与一步一步的说明

// Test for the ugliness.
if (window.location.hash === "#_=_"){

    // Check if the browser supports history.replaceState.
    if (history.replaceState) {

        // Keep the exact URL up to the hash.
        var cleanHref = window.location.href.split("#")[0];

        // Replace the URL in the address bar without messing with the back button.
        history.replaceState(null, null, cleanHref);

    } else {

        // Well, you're on an old browser, we can get rid of the _=_ but not the #.
        window.location.hash = "";

    }

}

循序渐进:

We'll only get into the code block if the fragment is #_=_. Check if the browser supports the HTML5 window.replaceState method. Clean the URL by splitting on # and taking only the first part. Tell history to replace the current page state with the clean URL. This modifies the current history entry instead of creating a new one. What this means is the back and forward buttons will work just the way you want. ;-) If the browser does not support the awesome HTML 5 history methods then just clean up the URL as best you can by setting the hash to empty string. This is a poor fallback because it still leaves a trailing hash (example.com/#) and also it adds a history entry, so the back button will take you back to #_-_.

了解更多关于历史的知识。

了解window.location的更多信息。

不知道他们为什么这样做，但是，你可以通过重置页面顶部的哈希来解决这个问题:

if (window.location.hash == "#_=_")
  window.location.hash = "";

这将删除附加字符到您的url

<script type="text/javascript">
 var idx=window.location.toString().indexOf("#_=_"); 
   if (idx > 0) { 
     window.location = window.location.toString().substring(0, idx); 
   } 
</script>

适用于PHP SDK用户

我只是通过在转发之前删除额外的部分来解决这个问题。

 $loginURL = $helper->getLoginUrl($redirectURL, $fbPermissions);
 $loginURL = str_replace("#_=_", "", $loginURL);
 header("Location: " . $loginURL);