轉載地址:http://blog.csdn.net/forezp/article/details/52987673
計時器
語法:
setInterval(代碼,交互時間)
參數說明:
代碼:要調用的函數或要執行的代碼串。
交互時間:週期性執行或調用表達式之間的時間間隔,以毫秒計(1s=1000ms)。
例子:
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>定時器</title>
<script type="text/javascript">
var attime;
function clock(){
var time=new Date();
attime= time.getHours()+':'+time.getMinutes()+':'+time.getSeconds();;
document.getElementById("clock").value = attime;
}
var timer = setInterval(clock,1000);
</script>
</head>
<body>
<form>
<input type="text" id="clock" size="50" />
</form>
</body>
</html>
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取消計時器
語法:
clearInterval(id_of_setInterval)
參數說明:
id_of_setInterval:由 setInterval() 返回的 ID 值。
任務:
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>計時器</title>
<script type="text/javascript">
function clock(){
var time=new Date();
document.getElementById("clock").value = time;
}
var i=setInterval("clock()",100);
</script>
</head>
<body>
<form>
<input type="text" id="clock" size="50" />
<input type="button" value="Stop" onclick="clearInterval(i)" />
</form>
</body>
</html>
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延時計時器 setTimeout()
setTimeout()計時器,在載入後延遲指定時間後,去執行一次表達式,僅執行一次。
語法:
setTimeout(代碼,延遲時間);
例子:
<!DOCTYPE HTML>
<html>
<head>
<script type="text/javascript">
function tinfo(){
var t=setTimeout("alert('Hello!')",5000);
}
</script>
</head>
<body>
<form>
<input type="button" value="start" onClick="tinfo()">
</form>
</body>
</html>
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要創建一個運行於無窮循環中的計數器,我們需要編寫一個函數來調用其自身。在下面的代碼,當按鈕被點擊後,輸入域便從0開始計數。
<!DOCTYPE HTML>
<html>
<head>
<script type="text/javascript">
var num=0;
function numCount(){
document.getElementById('txt').value=num;
num=num+1;
setTimeout("numCount()",1000);
}
</script>
</head>
<body>
<form>
<input type="text" id="txt" />
<input type="button" value="Start" onClick="numCount()" />
</form>
</body>
</html>
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取消計時器clearTimeout()
語法:
clearTimeout(id_of_setTimeout)
參數說明:
id_of_setTimeout:由 setTimeout() 返回的 ID 值。該值標識要取消的延遲執行代碼塊。
列子
<!DOCTYPE HTML>
<html>
<head>
<script type="text/javascript">
var num=0,i;
function timedCount(){
document.getElementById('txt').value=num;
num=num+1;
i=setTimeout(timedCount,1000);
}
setTimeout(timedCount,1000);
function stopCount(){
clearTimeout(i);
}
</script>
</head>
<body>
<form>
<input type="text" id="txt">
<input type="button" value="Stop" onClick="stopCount()">
</form>
</body>
</html>
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