div1.onmousedown = function(){
var l = event.clientX - div1.offsetLeft;
var t = event.clientY - div1.offsetTop;
document.onmousemove = function(){
var needX = event.clientX - l;
var needY = event.clientY - t;
if(needX<0){needX=0;}
if(needY<0){needY=0;}
//var w = screen.availWidth - div1.offsetWidth;
//var h = screen.availHeight - div1.offsetHeight;
var w = innerWidth - div1.offsetWidth;
var h = innerHeight - div1.offsetHeight;
if(needX>w){needX = w;}
if(needY>h){needY = h;}
div1.style.left = needX + 'px';
div1.style.top = needY + 'px';
}
document.onmouseup = function(){
//document.onmousedown = null;
document.onmousemove = null;
document.onmouseup = null;
}
}
**
- 功能说明 ID为div1 的div在body体中,可以被鼠标拖拽。
**