几周前，我做了一个JS函数，允许在我的应用程序中无限滚动。

首先，当用户访问网站时会显示一组数据：

// Add a callback that is triggered for each message.
var n = 25; // Step size for messages display.
$(window).load(function() {
lastMessagesQuery = messagesRef.limit(n); 
lastMessagesQuery.on('child_added', function (snapshot) {
  var message = snapshot.val();
  $('<div/>').text(message.text).prependTo($('#messagesDiv'));
  $('#messagesDiv')[0].scrollTop = $('#messagesDiv')[0].scrollHeight;
});
$('#messagesDiv').fadeTo(1000, 1);
});

然后，使无限滚动成为可能的函数：

// Pagination.
var i = 0; // Record variable.
function moreMessages () { 
i += n; // Record pagination updates. 
moreMessagesQuery = messagesRef; // Firebase reference.
moreMessagesQuery.on('value', function (snapshot) {
  var data = snapshot.exportVal(); // Fetch all data from Firebase as an Object.
  var keys = Object.keys(data).reverse(); // Due to the Keys are ordered from the oldest to the newest, it nessesary to change its sequence in order to display Firebase data snapshots properly.
  var total_keys = Object.keys(data).length;
  var k = keys[i]; // Key from where to start counting. Be careful what Key you pick.
  if (i < total_keys) { // Stop displaying messages when it reach the last one.
    lastMessagesQuery = messagesRef.endAt(null, k).limit(n); // Messages from a Key to the oldest.
    lastMessagesQuery.on('child_added', function (snapshot) {
      var message = snapshot.val();
      $('<div/>').text(message.text).appendTo($('#messagesDiv')).hide().fadeIn(1000); // Add set of messages (from the oldest to the newest) at the end of #messagesDiv.
    });
  }  
});
}

最后，无限滚动：

// Load more messages when scroll reach the bottom.
$(window).scroll(function() { 
if (window.scrollY == document.body.scrollHeight - window.innerHeight) {
  moreMessages();
}  
});

它适用于小型数据集。我希望这可以帮助您解决问题（或给您更多的想法）。

2015年10月更新

自从我最初的回答以来，Firebase有了增长，这意味着现在仅使用Javascript
API即可实现无限滚动非常容易：

首先，我建议在Firebase中创建一个索引。为此，我创建了一个：

{
   "rules": {
      ".read": true,
      ".write": false,
      "messages": {
         ".indexOn": "id"
      }
   }
}

然后，让我们使用Firebase进行一些魔术：

// @fb: your Firebase.
// @data: messages, users, products... the dataset you want to do something with.
// @_start: min ID where you want to start fetching your data.
// @_end: max ID where you want to start fetching your data.
// @_n: Step size. In other words, how much data you want to fetch from Firebase.
var fb = new Firebase('https://<YOUR-FIREBASE-APP>.firebaseio.com/');
var data = [];
var _start = 0;
var _end = 9;
var _n = 10;
var getDataset = function() {
   fb.orderByChild('id').startAt(_start).endAt(_end).limitToLast(_n).on("child_added", function(dataSnapshot) {
      data.push(dataSnapshot.val());
   });
   _start = _start + _n;
   _end = _end + _n;
}

最后，一个更好的 无限滚动 （没有jQuery）：

window.addEventListener('scroll', function() {
  if (window.scrollY === document.body.scrollHeight - window.innerHeight) {
     getDataset();
  } 
});

我在React中使用这种方法，无论您的数据量有多大，它的运行速度都非常快。