代码：
<html> <head></head> <style> body{padding:100px;} .fileDiv{float:left;width:100px;height:100px;text-align:center;line-height:100px;font-size:12px;border:1px solid #ccc;margin-right:10px;margin-bottom:10px;} .seled{border:1px solid red;background-color:#D6DFF7;} </style> <script type="text/javascript"> (function() { document.onmousedown = function() { var selList = []; var fileNodes = document.getElementsByTagName("div"); for ( var i = 0; i < fileNodes.length; i++) { if (fileNodes[i].className.indexOf("fileDiv") != -1) { fileNodes[i].className = "fileDiv"; selList.push(fileNodes[i]); } } var isSelect = true; var evt = window.event || arguments[0]; var startX = (evt.x || evt.clientX); var startY = (evt.y || evt.clientY); var selDiv = document.createElement("div"); selDiv.style.cssText = "position:absolute;width:0px;height:0px;font-size:0px;margin:0px;padding:0px;border:1px dashed #0099FF;background-color:#C3D5ED;z-index:1000;filter:alpha(opacity:60);opacity:0.6;display:none;"; selDiv.id = "selectDiv"; document.body.appendChild(selDiv); selDiv.style.left = startX + "px"; selDiv.style.top = startY + "px"; var _x = null; var _y = null; clearEventBubble(evt); document.onmousemove = function() { evt = window.event || arguments[0]; if (isSelect) { if (selDiv.style.display == "none") { selDiv.style.display = ""; } _x = (evt.x || evt.clientX); _y = (evt.y || evt.clientY); selDiv.style.left = Math.min(_x, startX) + "px"; selDiv.style.top = Math.min(_y, startY) + "px"; selDiv.style.width = Math.abs(_x - startX) + "px"; selDiv.style.height = Math.abs(_y - startY) + "px"; // ---------------- 关键算法 --------------------- var _l = selDiv.offsetLeft, _t = selDiv.offsetTop; var _w = selDiv.offsetWidth, _h = selDiv.offsetHeight; for ( var i = 0; i < selList.length; i++) { var sl = selList[i].offsetWidth + selList[i].offsetLeft; var st = selList[i].offsetHeight + selList[i].offsetTop; if (sl > _l && st > _t && selList[i].offsetLeft < _l + _w && selList[i].offsetTop < _t + _h) { if (selList[i].className.indexOf("seled") == -1) { selList[i].className = selList[i].className + " seled"; } } else { if (selList[i].className.indexOf("seled") != -1) { selList[i].className = "fileDiv"; } } } } clearEventBubble(evt); } document.onmouseup = function() { isSelect = false; if (selDiv) { document.body.removeChild(selDiv); showSelDiv(selList); } selList = null, _x = null, _y = null, selDiv = null, startX = null, startY = null, evt = null; } } })(); function clearEventBubble(evt) { if (evt.stopPropagation) evt.stopPropagation(); else evt.cancelBubble = true; if (evt.preventDefault) evt.preventDefault(); else evt.returnValue = false; } function showSelDiv(arr) { var count = 0; var selInfo = ""; for ( var i = 0; i < arr.length; i++) { if (arr[i].className.indexOf("seled") != -1) { count++; selInfo += arr[i].innerHTML + "\n"; } } alert("共选择 " + count + " 个文件，分别是：\n" + selInfo); } </script> <body> <div>file1</div> <div>file2</div> <div>file3</div> <div>file4</div> <div>file5</div> <div>file6</div> <div>file7</div> <div>file8</div> <div>file9</div> </body> </html>