<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Document</title> <style> * { margin: 0; padding: 0; left: 0px; top: 0px; } #box { width: 300px; height: 300px; background: green; position: absolute; } #id1 { position: absolute; left: 0px; top: 0px; width: 100px; height: 950px; border: 1px solid red; } </style> <script> var DOM, oX, oY; function tz(dom) { DOM = dom; } function un_tz() { DOM = null; } window.onmousemove = function(e) { var eve = e || window.event; if (DOM) { // 原点不可移动 if (DOM.offsetLeft < 0 && DOM.offsetTop < 0) { document.getElementById("box").style.left = 1 + "px"; document.getElementById("box").style.top = 1 + "px"; document.getElementById("box").style.marginLeft = 1 + "px"; document.getElementById("box").style. marginTop = 1 + "px"; } DOM.style.left = DOM.offsetLeft + eve.clientX - oX + 'px'; DOM.style.top = DOM.offsetTop + eve.clientY - oY + 'px'; } oX = eve.clientX; oY = eve.clientY; document.getElementById("box").innerHTML = "左上角原点相对body远点:(" + DOM.offsetLeft + "," + DOM.offsetTop + ")" + "<br/>" + "鼠标点相对body远点:(" + eve.pageX + "," + eve.pageY + ")" + "<br/>" + "鼠标点相对body远点:(" + eve.clientX + "," + eve.clientY + ")" + "<br/>"; document.getElementById("box").innerHTML +="body的大小:("+document.body.scrollWidth + "," +document.body.scrollHeight+")<br/>" ; document.getElementById("box").innerHTML +="屏幕分辨率:("+window.screen.width + "," +window.screen.height +")" ; } </script> </head> <body> <div id="id1"> </div> <div id="box" onmousedown="tz(this);" onmouseup="un_tz();"></div> </body> </html>