為什么點(diǎn)了 停止之后 點(diǎn)開始 再點(diǎn)停止 這個(gè)時(shí)間就是停不下來呢？
<!DOCTYPE HTML>
<html>
<head>
<title>計(jì)時(shí)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)" ?/>
? ? <input type="button" value="Start" onclick="setInterval('clock()',100)" />
? </form>
</body>
</html>
2015-11-06
<input type="button" value="Start" onclick="setInterval('clock()',100)" /> ?啟動(dòng)按鈕改成 ? onclick="i = setInterval('clock()',100)"
2015-11-06
<!DOCTYPE?HTML> <html> <head> <title>計(jì)時(shí)器</title> <script?type="text/javascript"> ???function?clock(){ ?????? ???var?time=new?Date();???????????????? ?????? ???document.getElementById("clock").value?=?time; ???} ????? ????? ???var?i=setInterval("clock()",100); ??? ???var?timer?=?null; ???function?start(){ ???????if(timer){ ???????????clearInterval(timer); ???????????timer?=?null; ???????} ???????setInterval('clock()',100) ???} ???? ????function?stop(){ ????????if(timer){ ???????????clearInterval(timer); ???????????timer?=?null; ???????} ????} </script> </head> <body> ??<form> ???? ????<input?type="text"?id="clock"?size="50"??/> ????<input?type="button"?value="Stop"?onclick="start()"??/> ????<input?type="button"?value="Start"?onclick="stop()"?/> ??</form> </body> </html>因?yàn)槟銢]有接收點(diǎn)按鈕開啟的定時(shí)的引用 ?那個(gè)i也不是，所以你就關(guān)不掉了