已经是深秋了，森林里那一望无际的林木都已光秃，让褐色的苔掩住它身上的皱纹。无情的秋天剥下了它们美丽的衣裳，它们只好枯秃地站在那里。
代码：
function drag(t,p){
var point = p || null,
target = t || null,
resultX = 0,
resultY = 0;
(!point)? point = target : ''; //如果没有拖动点，则拖动点默认为整个别拖动元素
function getPos(t){
var offsetLeft = 0,
offsetTop = 0,
offsetParent = t;
while(offsetParent){
offsetLeft+=offsetParent.offsetLeft;
offsetTop+=offsetParent.offsetTop;
offsetParent = offsetParent.offsetParent;
}
return {'top':offsetTop,'left':offsetLeft};
}
function core(){
var width = document.body.clientWidth || document.documentElement.clientWidth,
height = document.body.clientHeight || document.documentElement.clientHeight;
maxWidth = width - target.offsetWidth,
maxHeight = height - target.offsetHeight;
(resultX >= maxWidth)? target.style.left = maxWidth+'px' : (resultX > 0)?target.style.left = resultX +'px': ''; //重置默认位置。
(resultY >= maxHeight)? target.style.top = maxHeight +'px' : (resultY > 0)?target.style.top = resultY +'px':''; //重置默认位置。
point.onmousedown=function(e){
var e = e || window.event,
coordX = e.clientX,
coordY = e.clientY,
posX = getPos(target).left,
posY = getPos(target).top;
point.setCapture && point.setCapture(); //将Mouse事件锁定到指定元素上。
document.onmousemove=function(e){
var ev = e || window.event,
moveX = ev.clientX,
moveY = ev.clientY;
resultX = moveX - (coordX - posX); //结果值是坐标点减去被拖动元素距离浏览器左侧的边距
resultY = moveY - (coordY - posY);
(resultX > 0 )?((resultX < maxWidth)?target.style.left = resultX+'px' : target.style.left = maxWidth+'px') : target.style.left = '0px';
(resultY > 0 )?((resultY < maxHeight)?target.style.top = resultY+'px' : target.style.top = maxHeight+'px') : target.style.top = '0px';
ev.stopPropagation && ev.stopPropagation();
ev.preventDefault;
ev.returnValue = false;
ev.cancelBubble = true;
};
};
document.onmouseup=function(){ // 解决拖动时，当鼠标指向的DOM对象非拖动点元素时，无法触发拖动点的onmousedown的BUG。
document.onmousemove = null;
point.releaseCapture && point.releaseCapture(); // 将Mouse事件从指定元素上移除。
};
point.onmouseup=function(e){
var e = e || window.event;
document.onmousemove = null;
point.releaseCapture && point.releaseCapture();
};
}
core();
window.onresize = core;
}
使用方式：
drag(t,p) /* * 说明 * t 表示被拖动的元素 * p 表示拖动点 */ // 注意：如果省略拖动点，默认可拖动的区域是整个被拖动元素
以上就是小编为大家带来的自己封装的一个原生JS拖动方法(推荐)全部内容了，希望大家多多支持~
