定义和用法
draggable 上的 start、drag 和 stop 事件。拖拽开始时触发 start 事件，拖拽期间触发 drag 事件，拖拽停止时触发
stop 事件
示例
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title>jQuery UI 拖动（Draggable） - 事件</title>
<link rel="stylesheet" href="js/jquery-ui-1.12.1.custom/jquery-ui-1.12.1.custom/jquery-ui.min.css">
<style>
#draggable{
width: 16em;
padding: 0 1em;
}
#draggable ul li{
margin:1em 0;
padding:0.5em 0;
}
#draggable ul li span.ui-icon{
float: left;
}
#draggable ul li span.count{
font-weight: bold;
}
</style>
</head>
<body>
<div id="draggable" class="ui-widget ui-widget-content">
<p>请拖拽我，触发一连串的事件。</p>
<ul class="ui-helper-reset">
<li id="event-start" class="ui-state-default ui-corner-all">
<span class="ui-icon ui-icon-play">"start" 被调用</span>
<span class="count">0</span>x "start" 被调用
</li>
<li id="event-drag" class="ui-state-default ui-corner-all">
<span class="ui-icon ui-icon-arrow-4">"drag" 被调用</span>
<span class="count">0</span>x "drag" 被调用
</li>
<li id="event-stop" class="ui-state-default ui-corner-all">
<span class="ui-icon ui-icon-stop">"stop" 被调用</span>
<span class="count">0</span>x "stop" 被调用
</li>
</ul>
</div>
<script src="js/jquery-ui-1.12.1.custom/jquery-ui-1.12.1.custom/external/jquery/jquery.js" type="text/javascript" ></script>
<script src="js/jquery-ui-1.12.1.custom/jquery-ui-1.12.1.custom/jquery-ui.min.js"></script>
<script>
//获取对象
var $start_counter = $("#event-start"),
$drag_counter = $("#event-drag"),
$stop_counter = $("#event-stop"),
counts = [0,0,0];
$("#draggable").draggable({
start:function(){
counts[0]++;
updateCounterStatus($start_counter,counts[0]);
},
drag:function(){
counts[1]++;
updateCounterStatus($drag_counter,counts[1]);
},
stop:function(){
counts[2]++;
updateCounterStatus($stop_counter,counts[2]);
}
});
/**
* 更新数值
* @param {[object]} $event_counter [li对象]
* @param {[int]} new_count [次数]
*/
function updateCounterStatus($event_counter,new_count){
if (!$event_counter.hasClass('ui-state-hover')) {
$event_counter.addClass('"ui-state-hover"')
.siblings().removeClass('ui-state-hover');
}
$("span.count",$event_counter).text(new_count);
}
</script>
</body>
</html>
输出
