jQuery学习_具备吸附功能的拖曳框

在线演示:http://sandbox.runjs.cn/show/2drrwkrx

关键点:保持一个不变,鼠标拖动时与边框的距离 === 鼠标左击时与边框的距离

源码:

<!DOCTYPE html>
<html lang="zh">
<head>
	<meta charset="UTF-8">
	<title>具备吸附功能的拖曳</title>
	<link rel="stylesheet" type="text/css" href="http://sandbox.runjs.cn/uploads/rs/294/c4c2o6mh/base.css">
	
	<style>
		.c-box{
			position: absolute;
			top:100px;
			 100px;
			height: 100px;
			cursor: move;
			background-color: #9AFF9A;
		}
	</style>
	<script src="http://sandbox.runjs.cn/uploads/rs/294/c4c2o6mh/jquery.js"></script>
	
</head>
<body>
	<div ></div>
	<script>
		var box = $('#box');
		//鼠标按下
		box.mousedown(function(event) {
			if(event.which==1){ //左击
				var left = box.offset().left,//在当前视口的偏移,可以理解为到最终父级(body,html)的距离,别受到js定位父级		       //offsetparent的影响,与其对应的是jQuery中position()方法
					top = box.offset().top,
					d_x = event.pageX - left,
					d_y = event.pageY - top,
					wx = $(document).outerWidth(),//浏览器可视区域
					wy = $(document).outerHeight(),
					bx = box.width(),
					by = box.height();
				$(document).mousemove(function(event) { //绑定到doucument,防止移动太快脱离鼠标
					var x = event.pageX - d_x,
						y = event.pageY - d_y;
					if(x<40) x = 0;
					else if(wx-x-bx<40)
						x = wx - bx;
					if(y<40) y = 0;
					else if(wy-y-by<40)
						y = wy-by;
					box.css({
						left: x,
						top: y
					});

				});

				$(document).mouseup(function(event) {
					$(document).off('mousemove');
				});

				return false;//防止冒泡
			}
		});

	</script>
</body>
</html>

遇到的问题

(1)window中的top对象,参考资料:http://blog.163.com/zhaoyanping_1125/blog/static/201329153201206105031895/

jQuery学习_具备吸附功能的拖曳框

jQuery学习_具备吸附功能的拖曳框(2)防止鼠标脱离文本框,讲mouseup,mouseover绑定到doucuemnt

(3)区分offset()方法与position()方法

(4)可以将拖曳封装为通用方法

资料:判断鼠标左击与右击