document是位于html標簽之上的，可以說是權力最大的。下面的實例當你單擊頁面上的任何位置都會彈出“a”,正是運用了document的特性。
<script>
document.onclick=function(){
alert('a');
};
</script>
獲取鼠標位置clientX,clientY---注意這里僅僅只是可視區的鼠標位置
<script>
document.onclick=function(ev){
if(ev)
{
alert(ev.clientX+','+ev.clientY);
}
else{
alert(event.clientX+','+event.clentY);
};
};
</script>
或者
<script>
document.onclick=function(ev){
/* if(ev)
{
alert(ev.clientX+','+ev.clientY);
}
else{
alert(event.clientX+','+event.clentY);
};
};*/
var oEvent=ev||event;
alert(oEvent.clientX+','+oEvent.clientY);
};
</script>
事件冒泡---一層一層疊加的元素在一起，形成事件冒泡，比如下面的例子：document的最大范圍影響了div的響應。
<script>
window.onload=function(){
var obtn=document.getElementById('btn1');
var odiv=document.getElementById('div1');
obtn.onclick=function(ev){
var oEvent=ev||event;
odiv.style.display='block';
oEvent.cancelBubble=true;//清除冒泡
};
document.onclick=function(){
odiv.style.display='none';
};
};
</script>
</head>
<body>
<input type="button" value="顯示" id="btn1"/>
<div id="div1" style="width:100px;height:150px;background:#ccc;"></div>
</body>
鼠標移動---在可視區有效
<title>鼠標移動</title>
<script>
window.onmousemove=function(ev){
var oEvent=ev||event;
var odiv=document.getElementById('div1');
odiv.style.left=oEvent.clientX+'px';
odiv.style.top=oEvent.clientY+'px';
};
</script>
</head>
<body>
<div id="div1" style="width:50px;height:50px;background:blue;position:absolute;"></div>
</body>
鍵盤改變位置和方向---通過keycode獲取鍵盤的鍵值來執行相應的操作。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<style>
#div1 {width:100px; height:100px; background:#CCC; position:absolute;}
</style>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>無標題文檔</title>
<script>
document.onkeydown=function (ev)
{
var oEvent=ev||event;
var oDiv=document.getElementById('div1');
//← 37
//右 39
if(oEvent.keyCode==37)
{
oDiv.style.left=oDiv.offsetLeft-10+'px';
}
else if(oEvent.keyCode==39)
{
oDiv.style.left=oDiv.offsetLeft+10+'px';
}
};
</script>
</head>
<body>
<div id="div1"></div>
</body>
</html>
鼠標跟隨小尾巴
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<style>
div {width:10px; height:10px; background:red; position:absolute;}
</style>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>無標題文檔</title>
<script>
window.onload=function ()
{
var aDiv=document.getElementsByTagName('div');
var i=0;
document.onmousemove=function (ev)
{
var oEvent=ev||event;
for(i=aDiv.length-1;i>0;i--)
{
aDiv[i].style.left=aDiv[i-1].style.left;
aDiv[i].style.top=aDiv[i-1].style.top;
}
aDiv[0].style.left=oEvent.clientX+'px';
aDiv[0].style.top=oEvent.clientY+'px';
};
};
</script>
</head>
<body>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
</body>
</html>
keycode
<script>
document.onkeydown=function (ev)
{
var oEvent=ev||event;
alert(oEvent.keyCode);
};
</script>
ctrlKey---可以通過ctrl+enter組合鍵來提交內容
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>無標題文檔</title>
<script>
window.onload=function ()
{
var oBtn=document.getElementById('btn1');
var oTxt1=document.getElementById('txt1');
var oTxt2=document.getElementById('txt2');
oBtn.onclick=function ()
{
oTxt1.value+=oTxt2.value+'/n';
oTxt2.value='';
};
oTxt2.onkeydown=function (ev)
{
var oEvent=ev||event;
if(oEvent.ctrlKey && oEvent.keyCode==13)
{
oTxt1.value+=oTxt2.value+'/n';
oTxt2.value='';
}
};
};
</script>
</head>
<body>
<textarea id="txt1" rows="10" cols="40"></textarea><br />
<input id="txt2" type="text" />
<input id="btn1" type="button" value="留言" />
</body>
</html>
