表单相关特效整理(转自http://blog.youkuaiyun.com/arielxp/archive/2005/02/24/299525.aspx)-优快云博客

该博客主要提供了一系列JavaScript代码示例，包括控制输入框输入内容（如只能输入中文、数字等）、处理键盘按键（如ENTER键跳转、获取键值、限制按键）、IP地址输入验证、防止后退清空文本框、TEXTAREA自适应行数、上传预览图片等功能。

只能是一些限定的东西

运行代码框
ENTER键可以让光标移到下一个输入框 <input onkeydown="if(event.keyCode==13)event.keyCode=9" > <br> 只能是中文<input onkeyup="value=value.replace(/[ -~]/g,'')" onkeydown="if(event.keyCode==13)event.keyCode=9"> <br> 屏蔽输入法<input style="ime-mode:disabled" onkeydown="if(event.keyCode==13)event.keyCode=9"> <br> 只能输入英文和数字<input onkeyup="value=value.replace(/[/W]/g,'') "onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^/d]/g,''))" onkeydown="if(event.keyCode==13)event.keyCode=9"> <br> 只能是数字<input onkeyup="value=value.replace(/[^/d]/g,'') "onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^/d]/g,''))"><br> 只能显示，不能修改<input readonly value="只能显示，不能修改">
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只能是数字，判断按键的值。

运行代码框
<script language=javascript> function onlyNum() { if(!((event.keyCode>=48&&event.keyCode<=57)||(event.keyCode>=96&&event.keyCode<=105)||(event.keyCode==8))) event.returnValue=false; } </script> <input onkeydown="onlyNum();">
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附：获取键盘的KeyCode

运行代码框
<html> <head> <script language="javascript"> ns4 = (document.layers) ? true : false; ie4 = (document.all) ? true : false; function keyDown(e){ if(ns4){ var nkey=e.which; var iekey='现在是ns浏览器'; var realkey=String.fromCharCode(e.which); } if(ie4){ var iekey=event.keyCode; var nkey='现在是ie浏览器'; var realkey=String.fromCharCode(event.keyCode); if(event.keyCode==32){realkey='/' 空格/''} if(event.keyCode==13){realkey='/' 回车/''} if(event.keyCode==27){realkey='/' Esc/''} if(event.keyCode==16){realkey='/' Shift/''} if(event.keyCode==17){realkey='/' Ctrl/''} if(event.keyCode==18){realkey='/' Alt/''} } alert('ns浏览器中键值:'+nkey+'/n'+'ie浏览器中键值:'+iekey+'/n'+'实际键为'+realkey); } document.onkeydown = keyDown; if(ns4){ document.captureEvents(Event.KEYDOWN);} </script> </head> <body> //Javascript Document. <hr> <center> <h3>请按任意一个键。。。。</h3> </center> </body> </html>
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限制网页用键盘

运行代码框
<body onkeydown="alert('禁用');return false;"> 限制键盘的某个键：body onkeydown="if(event.keyCode==num){alert('禁用');return false;}
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再加个找按键的值

运行代码框
<script> function show(){ alert("ASCII代码是："+event.keyCode); } </script> <body onkeydown="show()">
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只能是IP地址

运行代码框
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <meta name="GENERATOR" content="Microsoft FrontPage 4.0"> <meta name="ProgId" content="FrontPage.Editor.Document"> <style> .a3{width:30;border:0;text-align:center} </style> <script> function mask(obj){ obj.value=obj.value.replace(/[^/d]/g,'') key1=event.keyCode if (key1==37 || key1==39) { obj.blur(); nextip=parseInt(obj.name.substr(2,1)) nextip=key1==37?nextip-1:nextip+1; nextip=nextip>=5?1:nextip nextip=nextip<=0?4:nextip eval("ip"+nextip+".focus()") } if(obj.value.length>=3) if(parseInt(obj.value)>=256 || parseInt(obj.value)<=0) { alert(parseInt(obj.value)+"IP地址错误！") obj.value="" obj.focus() return false; } else { obj.blur(); nextip=parseInt(obj.name.substr(2,1))+1 nextip=nextip>=5?1:nextip nextip=nextip<=0?4:nextip eval("ip"+nextip+".focus()") } } function mask_c(obj) { clipboardData.setData('text',clipboardData.getData('text').replace(/[^/d]/g,'')) } </script> <title>IP地址输入</title> </head> <body>IP地址输入 <div style="border-width:1;border-color:balck;border-style:solid;width:165;font-size:9pt"> <input type=text name=ip1 maxlength=3 class=a3 onkeyup="mask(this)" onbeforepaste=mask_c()>. <input type=text name=ip2 maxlength=3 class=a3 onkeyup="mask(this)" onbeforepaste=mask_c()>. <input type=text name=ip3 maxlength=3 class=a3 onkeyup="mask(this)" onbeforepaste=mask_c()>. <input type=text name=ip4 maxlength=3 class=a3 onkeyup="mask(this)" onbeforepaste=mask_c()> </div> </body> </html>
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用#default#savehistory防止后退清空text文本框：

运行代码框
<HTML> <HEAD> <META NAME="save" CONTENT="history"> <STYLE> .saveHistory {behavior:url(#default#savehistory);} </STYLE> </HEAD> <BODY> <INPUT class=saveHistory type=text id=oPersistInput> <input type=button onclick='javascript:location.href="http://www.cnbruce.com/red/"' value='点击进入,再按后退键试试？'> </BODY> </HTML>
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TEXTAREA自适应文字行数的多少

运行代码框
<textarea rows=1 name=s1 cols=27 onpropertychange="this.style.posHeight=this.scrollHeight">
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上传预览图片

运行代码框
<img id=pic src=http://www.cnbruce.com/images/logo.gif> <input type=file name=file><input type=button onclick=pic.src=file.value value=预览图片> <input type=button onclick=alert(file.value) value=图片地址> <input type=button onclick="file.outerHTML=file.outerHTML.replace(/value=/w/g,'')" value="清除file里字">
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去掉下拉选项的边框

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<div style="position: absolute; left: 10px; top: 10px; width: 115px; height: 20px; clip:rect(2 114 20 2);"> <select> <option >cnpeople</option> <option >cnrose</option> <option >cnbruce</option> </select> </font> </div>
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下拉列表打开窗口

运行代码框
<select onChange="if(this.selectedIndex && this.selectedIndex!=0){window.open(this.value);}this.selectedIndex=0;"> <option selected>更多链接……</option> <option value="http://www.cnbruce.com">cnbruce</option> <option value="http://daonet.myrice.com/old/">daonet</option> <option value="http://www.blueidea.com">blue!dea </select>
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通过下拉菜单传递跳转

运行代码框
<form action="showlog.asp?" > <select name="cat_id" onpropertychange="form.submit();"> <option value="">==请选择==</option> <option value="11">11</option> <option value="22">22</option> </select> </form>
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TAB键在文本域中的体现

运行代码框
<script> function editTab() { var code, sel, tmp, r var tabs="" event.returnValue = false sel =event.srcElement.document.selection.createRange() r = event.srcElement.createTextRange() switch (event.keyCode) { case (8) : if (!(sel.getClientRects().length > 1)) { event.returnValue = true return } code = sel.text tmp = sel.duplicate() tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top) sel.setEndPoint("startToStart", tmp) sel.text = sel.text.replace(/^/t/gm, "") code = code.replace(/^/t/gm, "").replace(//r/n/g, "/r") r.findText(code) r.select() break case (9) : if (sel.getClientRects().length > 1) { code = sel.text tmp = sel.duplicate() tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top) sel.setEndPoint("startToStart", tmp) sel.text = "/t"+sel.text.replace(//r/n/g, "/r/t") code = code.replace(//r/n/g, "/r/t") r.findText(code) r.select() } else { sel.text = "/t" sel.select() } break case (13) : tmp = sel.duplicate() tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top) tmp.setEndPoint("endToEnd", sel) for (var i=0; tmp.text.match(/^[/t]+/g) && i<tmp.text.match(/^[/t]+/g)[0].length; i++) tabs += "/t" sel.text = "/r/n"+tabs sel.select() break default : event.returnValue = true break } } </script> <textarea cols=75 rows=20 onkeydown="editTab()"> <script> alert("ok") </script></textarea>
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文本框的上/下拉

运行代码框
<form name="cnbruce"> <textarea name="com"> </textarea> </form> <SPAN title='放大输入框' style='FONT-SIZE: 12px; CURSOR: hand' onclick=document.cnbruce.com.rows+=4>向下</SPAN> <SPAN title='缩小输入框' style='FONT-SIZE: 12px; CURSOR: hand' class='arrow' onclick='if(document.cnbruce.com.rows>=4)document.cnbruce.com.rows-=4;else return false'>向上</SPAN>
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一个复选框，点击之后一组复选框全部都选上

运行代码框
<input type="checkbox" name="checkA" onpropertychange="for(i=0;i<A.children.length;i++){A.children[i].checked=this.checked}">a <br> <span id="A"> <input type="checkbox" name="A1"> <input type="checkbox" name="A2"> <input type="checkbox" name="A3"> </span>
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Debug Textarea：在线写 js 脚本的时候，用来即时查错的东西！

运行代码框
<HTML> <HEAD> <TITLE>Debug Textarea</TITLE> <meta http-equiv='Content-Type' content='text/html; charset=gb2312'> </HEAD> <style> * { font-size: 12px } body { margin: 10px; padding: 0px } table.list{ cursor: default; border:1px solid #cccccc background-color: #cccccc; border-collapse: collapse; border-Color: #cccccc; } </style> <script language="javascript"> // Coded by windy_sk <windy_sk@126.com> 20040205 function reportError(msg,url,line) { var str = "You have found an error as below: /n/n"; str += "Err: " + msg + " on line: " + line; alert(str); return true; } window.onerror = reportError; document.onkeydown = function() { if(event.ctrlKey){ switch(event.keyCode) { case 82: //r runcode(); break; case 83: //s savecode(); break; case 71: //g goto(prompt('Please input the line number', '1')); break; case 65: //a document.execCommand("SelectAll"); break; case 67: //c document.execCommand("Copy"); break; case 88: //x document.execCommand("Cut"); break; case 86: //v document.execCommand("Paste"); break; case 90: //z document.execCommand("Undo"); break; case 89: //y document.execCommand("Redo"); break; default: break; } event.keyCode = 0; event.returnValue = false; } return; } function show_ln(){ var txt_ln = document.getElementById('txt_ln'); var txt_main = document.getElementById('txt_main'); txt_ln.scrollTop = txt_main.scrollTop; while(txt_ln.scrollTop != txt_main.scrollTop) { txt_ln.value += (i++) + '/n'; txt_ln.scrollTop = txt_main.scrollTop; } return; } function editTab(){ var code, sel, tmp, r var tabs='' event.returnValue = false sel =event.srcElement.document.selection.createRange() r = event.srcElement.createTextRange() switch (event.keyCode){ case (8) : if (!(sel.getClientRects().length > 1)){ event.returnValue = true return } code = sel.text tmp = sel.duplicate() tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top) // 出错检验代码~~~~~~ if(sel.parentElement() != tmp.parentElement()) return; sel.setEndPoint('startToStart', tmp) sel.text = sel.text.replace(/^/t/gm, '') code = code.replace(/^/t/gm, '').replace(//r/n/g, '/r') r.findText(code) r.select() break case (9) : if (sel.getClientRects().length > 1){ code = sel.text tmp = sel.duplicate() tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top) // 出错检验代码~~~~~~ if(sel.parentElement() != tmp.parentElement()) return; sel.setEndPoint('startToStart', tmp) sel.text = '/t'+sel.text.replace(//r/n/g, '/r/t') code = code.replace(//r/n/g, '/r/t') r.findText(code) r.select() }else{ sel.text = '/t' sel.select() } break case (13) : tmp = sel.duplicate() tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top) // 出错检验代码~~~~~~ if(sel.parentElement() != tmp.parentElement()) return; tmp.setEndPoint('endToEnd', sel) for (var i=0; tmp.text.match(/^[/t]+/g) && i<tmp.text.match(/^[/t]+/g)[0].length; i++) tabs += '/t' sel.text = '/r/n'+tabs sel.select() break default : event.returnValue = true break; } return; } function runcode() { var str = document.getElementById("txt_main").value; var code_win = window.open('about:blank'); code_win.document.open(); code_win.document.writeln("<script>"); code_win.document.writeln("function reportError(msg,url,line){/nline-=14;/nvar str='You have found an error as below: //n//n';/nstr+='Err: '+msg+' on line: '+(line);/nalert(str);/nopener.goto(line);/nopener.focus();/nwindow.onerror=null;/nsetTimeout('self.close()',10);/nreturn true;/n}"); code_win.document.writeln("window.onerror = reportError;"); code_win.document.writeln("<//script>"); code_win.document.writeln(str); code_win.document.close(); return; } function savecode() { var str = document.getElementById("txt_main").value; var code_win = window.open('about:blank','_blank','top=10000'); code_win.document.open(); code_win.document.writeln(str); code_win.document.close(); code_win.document.execCommand('saveas','','code.html'); code_win.close(); return; } function goto(ln) { if(!/^/d+$/.test(ln)) return; var obj = document.getElementById("txt_main"); var rng = obj.createTextRange(); var arr = obj.value.replace(//r/, "").split(//n/); if(ln>arr.length) ln = arr.length; var str_tmp = ""; for(var i=0; i<ln-1; i++) { str_tmp += arr[i]; } rng.moveStart('character',str_tmp.length+1); str_tmp = ""; for(i=ln; i<arr.length; i++) { str_tmp += arr[i]; } rng.moveEnd('character',-str_tmp.length); rng.select(); return; } window.onload = function() {document.getElementById("txt_main").value = "<script>/nalert(')/n<//script>";} </script> <BODY> <table width='600' class='list' border='1' bgcolor='#eeeeee' bordercolorlight='#000000' bordercolordark='#FFFFFF' cellpadding='0' cellspacing='0'> <tr bgcolor='#cccccc'> <td colspan='2' height='20' align='center'><b>Debug Textarea</b></td> </tr> <tr> <td colspan='2'> <table width='95%' border='0' align='center' > <tr> <td align='center'><br /> <textarea id='txt_ln' name='content' rows='10' style='width:40px;overflow:hidden;height:200px;border-right:0px;text-align:right;line-height:14px' onselectstart='this.nextSibling.focus();return false' readonly></textarea><textarea id='txt_main' name='content' rows='10' cols='80' onkeydown='editTab()' onkeyup='show_ln()' onscroll='show_ln()' wrap='off' style='overflow:auto;height:200px;padding-left:5px;border-left:0px;line-height:14px'></textarea> <script>for(var i=1; i<=20; i++) document.getElementById('txt_ln').value += i + '/n';</script> </td> </tr> <tr> <td align='center'><br /> <input type='button' value=' 运行 ' onclick='runcode()' accesskey='r'>   <input type='button' value=' 保存 ' onclick='savecode()' accesskey='s'>   <input type='button' value=' 跳转 ' onclick="goto(prompt('Please input the line number', '1'))" accesskey='g'>   </td> </tr> </table> </td> </tr> </table> </BODY> </HTML>
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