http://www.tocus.com.cn/?send=article_show&id=34&class=2
可以循环计时，而对于页面刷新，我们可以屏蔽鼠标右键、Ctrl+N、Shift+F10、Alt+F4、F11、F5刷新、退格键来达到效果
<script>
//屏蔽鼠标右键、Ctrl+N、Shift+F10、F11、F5刷新、退格键
function document.oncontextmenu(){event.returnValue=false}//屏蔽鼠标右键
function window.onhelp(){return false} //屏蔽F1帮助
function document.onkeydown(){
if((window.event.altKey)&&((window.event.keyCode==37)||(window.event.keyCode==39))){
//屏蔽Alt+方向键←
//屏蔽Alt+方向键→
event.returnValue=false
}
if((event.keyCode==8)||(event.keyCode==116)||(event.ctrlKey &&event.keyCode==82)){
//屏蔽退格删除键
//屏蔽F5刷新键
//Ctrl+R
event.keyCode=0
event.returnValue=false
}
if(event.keyCode==122){event.keyCode=0event.returnValue=false}//屏蔽F11
if(event.ctrlKey &&event.keyCode==78)event.returnValue=false //屏蔽Ctrl+n
if(event.shiftKey &&event.keyCode==121)event.returnValue=false //屏蔽shift+F10
if(window.event.srcElement.tagName=="A" &&window.event.shiftKey)
window.event.returnValue=false //屏蔽shift加鼠标左键新开一网页
if((window.event.altKey)&&(window.event.keyCode==115)){ //屏蔽Alt+F4
window.showModelessDialog("about:blank","","dialogWidth:1pxdialogheight:1px")
return false
}
}
</script>
<script language='javascript'>var _t
var _h = 0
var _m = 1
var _s = 0
var _v = formatTime(_h + ':' + _m + ':' + _s)
function doTime()
{
_s --
if (_s == -1)
{
_m --
_s = 59
}
if (_m == -1)
{
_h --
_m = 59
}
var _b = ((_h == 0) &&(_m == 0) &&(_s == 0))
if (_b)
{
_v = 'Welcome To RTBBS.NET'
clearTimeout(_t)
}
else
{
_v = formatTime(_h + ':' + _m + ':' + _s)
_t = setTimeout('doTime()', 1000)
}
document.all.oTime.innerHTML = _v
}
function formatTime(_time)
{
return _time.replace(/\b(\w)\b/g, '0$1')
}
function start_time()
{
document.all.oTime.innerHTML = _v
_t = setTimeout('doTime()', 1000)
}
</script>
<span id='oTime'></span>
<input type="button" name="button2" value="计时开始" onclick='start_time()' >
</body>
</html>
</html>
<!doctype html><html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<input placeholder="请输入时间" id="inp">
<button onclick="go()">start</button><button onclick="stop()">stop</button><button id="jixu" onclick="jixu()" style="display: none">continue</button>
<div id="result"></div>
<script>
var time,
div=document.getElementById('result'),
stopState = false
function go(){
time = document.getElementById('inp').value
timeout()
}
function timeout(){
if(time ==''){
alert('请输入时间')
return
}
setTimeout(function(){
time--
div.innerText = time
if(time!==0 && !stopState){
timeout()
}
},1000)
}
function jixu(){
time = Number(document.getElementById('result').innerText)
document.getElementById('jixu').style.display = 'none'
stopState =false
timeout()
}
function stop(){
document.getElementById('jixu').style.display = ''
stopState = true
}
</script>
</body>
</html>
