JavaScript实用的一些技巧

1 . oncontextmenu = " window.event.returnValue=false "  将彻底屏蔽鼠标右键
< table border oncontextmenu = return ( false ) >< td > no </ table >  可用于Table 
2 .  < body onselectstart = " return false " >  取消选取、防止复制

3 . onpaste = " return false "  不准粘贴

4 . oncopy = " return false; "  oncut = " return false; "  防止复制

5 .  < link rel = " Shortcut Icon "  href = " favicon.ico " >  IE地址栏前换成自己的图标

6 .  < link rel = " Bookmark "  href = " favicon.ico " >  可以在收藏夹中显示出你的图标

7 .  < input style = " ime-mode:disabled " >  关闭输入法

8 . 永远都会带着框架
< script language = " JavaScript " ><!--
if  (window  ==  top)top.location.href  =   " frames.htm " ;  // frames.htm为框架网页
//  --></script>

9 . 防止被人frame
< SCRIPT LANGUAGE = JAVASCRIPT ><!--  
if  (top.location  !=  self.location)top.location = self.location;
//  --></SCRIPT>

10 . 网页将不能被另存为
< noscript >< iframe src =* .html ></ iframe ></ noscript >  

11 .  < input type = button value = 查看网页源代码 
onclick = " window.location =  " view - source: " +  " http: // www.pconline.com.cn"">

12 .删除时确认
< a href = " javascript:if(confirm( " 确实要删除吗 ? " ))location= " boos.asp ?& areyou = 删除 & page = 1 "" > 删除 </ a >  

13 . 取得控件的绝对位置
// Javascript
< script language = " Javascript " >
function  getIE(e){
var  t = e.offsetTop;
var  l = e.offsetLeft;
while (e = e.offsetParent){
t += e.offsetTop;
l += e.offsetLeft;
}
alert( " top= " + t + " /nleft= " + l);
}
</ script >

// VBScript
< script language = " VBScript " ><!--
function  getIE()
dim t,l,a,b
set a = document.all.img1
t = document.all.img1.offsetTop
l = document.all.img1.offsetLeft
while  a.tagName <> " BODY "
set a  =  a.offsetParent
t = t + a.offsetTop
l = l + a.offsetLeft
wend
msgbox  " top= " & t & chr( 13 ) & " left= " & l, 64 , " 得到控件的位置 "
end  function
--></ script >

14 . 光标是停在文本框文字的最后
< script language = " javascript " >
function  cc()
{
var  e  =  event.srcElement;
var  r  = e.createTextRange();
r.moveStart( " character " ,e.value.length);
r.collapse( true );
r.select();
}
</ script >
< input type = text name = text1 value = " 123 "  onfocus = " cc() " >

15 . 判断上一页的来源
javascript:document.referrer

16 . 最小化、最大化、关闭窗口
< object id = hh1 classid = " clsid:ADB880A6-D8FF-11CF-9377-00AA003B7A11 " >  
< param name = " Command "  value = " Minimize " ></ object >
< object id = hh2 classid = " clsid:ADB880A6-D8FF-11CF-9377-00AA003B7A11 " >  
< param name = " Command "  value = " Maximize " ></ object >
< OBJECT id = hh3 classid = " clsid:adb880a6-d8ff-11cf-9377-00aa003b7a11 " >
< PARAM NAME = " Command "  VALUE = " Close " ></ OBJECT >
< input type = button value = 最小化 onclick = hh1.Click() >
< input type = button value = 最大化 onclick = hh2.Click() >
< input type = button value = 关闭 onclick = hh3.Click() >
本例适用于IE


17 .屏蔽功能键Shift,Alt,Ctrl
< script >
function  look(){ 
if (event.shiftKey) 
alert( " 禁止按Shift键! " );  // 可以换成ALT　CTRL
} 
document.onkeydown = look; 
</ script >

18 . 网页不会被缓存
< META HTTP - EQUIV = " pragma "  CONTENT = " no-cache " >
< META HTTP - EQUIV = " Cache-Control "  CONTENT = " no-cache, must-revalidate " >
< META HTTP - EQUIV = " expires "  CONTENT = " Wed, 26 Feb 1997 08:21:57 GMT " >
或者 < META HTTP - EQUIV = " expires "  CONTENT = " 0 " >

19 .怎样让表单没有凹凸感？
< input type = text style = " border:1 solid #000000 " >  
或
< input type = text style = " border-left:none; border-right:none; border-top:none; border-bottom: 

1 solid #000000 " ></ textarea >

20 . < div >< span >&< layer > 的区别？ 
< div > (division)用来定义大段的页面元素，会产生转行 
< span > 用来定义同一行内的元素，跟 < div > 的唯一区别是不产生转行 
< layer > 是ns的标记，ie不支持，相当于 < div >




21 .让弹出窗口总是在最上面:
< body onblur = " this.focus(); " >

22 .不要滚动条 ?  
让竖条没有: 
< body style = " overflow:scroll;overflow-y:hidden " >  
</ body >  
让横条没有: 
< body style = " overflow:scroll;overflow-x:hidden " >  
</ body >  
两个都去掉？更简单了 
< body scroll = " no " >  
</ body >  

23 .怎样去掉图片链接点击后，图片周围的虚线？
< a href = " # "  onFocus = " this.blur() " >< img src = " logo.jpg "  border = 0 ></ a >

24 .电子邮件处理提交表单
< form name = " form1 "  method = " post "  action = " mailto:****@***.com "  enctype = " text/plain " >  
< input type = submit >
</ form >

25 .在打开的子窗口刷新父窗口的代码里如何写？
window.opener.location.reload()

26 .如何设定打开页面的大小
< body onload = " top.resizeTo(300,200); " >
打开页面的位置 < body onload = " top.moveBy(300,200); " >

27 .在页面中如何加入不是满铺的背景图片,拉动页面时背景图不动 
< STYLE >  
body 
{background - image:url(logo.gif); background - repeat:no - repeat; 
background - position:center;background - attachment: fixed} 
</ STYLE >  

28 . 检查一段字符串是否全由数字组成
< script language = " Javascript " ><!--
function  checkNum(str){ return  str.match( // D/)==null}
alert(checkNum( " 1232142141 " ))
alert(checkNum( " 123214214a1 " ))
//  --></script>

29 . 获得一个窗口的大小
document.body.clientWidth; document.body.clientHeight

30 . 怎么判断是否是字符
if  ( / [ ^/ x00 -/ xff] / g.test(s)) alert( " 含有汉字 " );
else  alert( " 全是字符 " );

31 .TEXTAREA自适应文字行数的多少
< textarea rows = 1  name = s1 cols = 27  onpropertychange = " this.style.posHeight=this.scrollHeight " >
</ textarea >


32 . 日期减去天数等于第二个日期
< script language = Javascript >
function  cc(dd,dadd)
{
// 可以加上错误处理
var  a  =   new  Date(dd)
a  =  a.valueOf()
a  =  a  -  dadd  *   24   *   60   *   60   *   1000
a  =   new  Date(a)
alert(a.getFullYear()  +   " 年 "   +  (a.getMonth()  +   1 )  +   " 月 "   +  a.getDate()  +   " 日 " )
}
cc( " 12/23/2002 " , 2 )
</ script >

33 . 选择了哪一个Radio
< HTML >< script language = " vbscript " >
function  checkme()
for  each ob  in  radio1
if  ob.checked then window.alert ob.value
next
end  function
</ script >< BODY >
< INPUT name = " radio1 "  type = " radio "  value = " style "  checked > Style
< INPUT name = " radio1 "  type = " radio "  value = " barcode " > Barcode
< INPUT type = " button "  value = " check "  onclick = " checkme() " >
</ BODY ></ HTML >

34 .脚本永不出错
< SCRIPT LANGUAGE = " JavaScript " >  
<!--  Hide 
function  killErrors() { 
return   true ; 
} 
window.onerror  =  killErrors; 
//  --> 
</ SCRIPT >

35 .ENTER键可以让光标移到下一个输入框
< input onkeydown = " if(event.keyCode==13)event.keyCode=9 " >

36 . 检测某个网站的链接速度：
把如下代码加入 < body > 区域中:
< script language = Javascript >
tim = 1
setInterval( " tim++ " , 100 )
b = 1
var  autourl = new  Array()
autourl[ 1 ] = " www.njcatv.net "
autourl[ 2 ] = " javacool.3322.net "
autourl[ 3 ] = " www.sina.com.cn "
autourl[ 4 ] = " www.nuaa.edu.cn "
autourl[ 5 ] = " www.cctv.com "
function  butt(){
document.write( " <form name=autof> " )
for ( var  i = 1 ;i < autourl.length;i ++ )
document.write( " <input type=text name=txt " + i + "  size=10 value=测试中……> =》<input type=text 
name=url " + i + "  size=40> =》<input type=button value=GO 

onclick=window.open(this.form.url "