为什么用focus传递参数获取失败，用click获取成功
代码如下
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-type" content="text/html; charset=utf-8" />
<script src="http://libs.baidu.com/jquery/1.9.1/jquery.js"></script>
</head>
<body>
<input type="text">
<br>
<button>focus传参数</button>
<br>
<button>click传参数</button>
<script type="text/javascript">
$("input").on("focus",function(event,title) {
alert(title) //为什么参数传递失败
});
$("button:first").click(function(){
$("input").trigger("focus","focus传参数");
})
$("input").on("click",function(event,title) {
alert(title)
});
$("button:last").click(function(){
$("input").trigger("click","click传参数");
})
</script>
</body>
</html>
