为什么在ie下，上下左右没用呢？

Question

document.onkeypress= viewKeyInfo; 
用onkeydown试试，onkeypress一般用于可见字符

Answer 1

<script type="text/javascript"> 
//By 枫岩@CnLei.Com 
function $(s){ 
  return document.getElementById(s)?document.getElementById(s):s; 
} 
function viewKeyInfo(event){ 
  var currKey=0,CapsLock=0; 
  var e=event||window.event; 
  currKey=e.keyCode||e.which||e.charCode; 
  CapsLock=currKey >=65 && currKey <=90; 
  $("type").innerHTML=e['type']; 
  $("currKey").innerHTML=String.fromCharCode(currKey); 
  $("Decimal").innerHTML=currKey; 
  $("keyCode").innerHTML=e['keyCode']; 
  $("charCode").innerHTML=e['charCode']; 
  $("caps").innerHTML=CapsLock; 
  $("shiftKey").innerHTML=e['shiftKey']; 
  $("ctrlKey").innerHTML=e['ctrlKey']; 
  $("repeat").innerHTML=e['repeat']; 
  $("which").innerHTML=e['which']; 
alert(currKey); 
} 
document.onkeyup= viewKeyInfo; 
alert(currKey); 
//  alert(e['keyCode']); 
</script> 
<p>请按下任意键看测试效果： </p> 
type: <span id="type"> </span> <br /> 
当前Key: <span id="currKey"> </span> <br /> 
Decimal: <span id="Decimal"> </span> <br /> 
keyCode: <span id="keyCode"> </span> <strong>注：在FF下,keyCode始终为0 </strong> <br /> 
which: <span id="which"> </span> <strong>注：在IE下,which始终为undefined ； 在Opera下，keyCode和charCode二者的值相同 </strong> <br /> 
charCode: <span id="charCode"> </span> <strong>注：在IE、Opera下,charCode始终为undefined ; 在FF下，which和charCode二者的值相同 </strong> <br /> 
大写: <span id="caps"> </span> <br /> 
altKey: <span id="altKey"> </span> <br /> 
ctrlKey: <span id="ctrlKey"> </span> <br /> 
shiftKey: <span id="shiftKey"> </span> <br /> 
repeat: <span id="repeat"> </span> <br /> 
<style type="text/css" media="all"> 
body {color:#999;font:normal 14px tahoma,宋体,Geneva,Arial,sans-serif;} 
span {color:#f00;font-weight:bold;padding:0 5px;} 
strong {color:#090;font-weight:normal;padding:0 5px;} 
</style> 

Answer 2

document.onkeyup= viewKeyInfo; 
//alert(currKey);<----这个要屏蔽掉吧?