下拉加载更多

<script type="text/javascript">
(function(window) {
	var i = 2;
	var moreData=true;
	// 获取当前滚动条的位置 
    function getScrollTop() { 
	    var scrollTop = 0; 
	    if (document.documentElement && document.documentElement.scrollTop) { 
	    	scrollTop = document.documentElement.scrollTop; 
	    } else if (document.body) { 
	    	scrollTop = document.body.scrollTop; 
	    } 
	    return scrollTop; 
    } 
    // 获取当前可视范围的高度 
    function getClientHeight() { 
	    var clientHeight = 0; 
	    if (document.body.clientHeight && document.documentElement.clientHeight) { 
	    	clientHeight = Math.min(document.body.clientHeight, document.documentElement.clientHeight); 
	    } 
	    else { 
	    	clientHeight = Math.max(document.body.clientHeight, document.documentElement.clientHeight); 
	    } 
	    return clientHeight; 
    }
    // 获取文档完整的高度 
    function getScrollHeight() { 
    	return Math.max(document.body.scrollHeight, document.documentElement.scrollHeight); 
    }
    var _text = document.querySelector('.refreshText'),
    _container = document.getElementById('refreshContainer');
    var throttle = function(method, context){
		  clearTimeout(method.tId);
		  method.tId = setTimeout(function(){
		    method.call(context);
		  }, 300);
	}
    function fetchData() {
    	setTimeout(function() {
    		_container.insertAdjacentHTML('beforeend', '<li>new add...</li>');
    	}, 1000);
    }
    window.onscroll = function() {
    	if(moreData){
			if (getScrollTop() + getClientHeight() >= getScrollHeight()) {
				_text.innerText = '加载中...';
				// throttle(fetchData);
				$.ajax({
					type: 'POST',
					// dataType: 'JSON',
					url: '${path}/', //服务路径
					data: {
						page:i
					},
					success: function (res) {
						console.log("res---" + JSON.stringify(res))
						if (res == "") {
							console.log("data is null");
							_text.innerText = '';
							moreData = false;
						} else {
							_container.insertAdjacentHTML('beforeend', res);
							i++;
						}
					},
					error: function () {
						$(this).removeAttr("disabled");
						alert("换卡异常失败！");
					}
				});

			}
		}
    };
})(window);
</script>

有时候 会出现放10条数据下拉无响应的情况,因为10条数据没有把页面铺满.触底事件无法执行.可让一页显示20条数据