如何取消重复开启的计时器？
qq_轮滑到老_04284587
2017-05-31 09:54
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>计时器</title>
<script type="text/javascript">
var num=0;
var i;
function startCount(){
document.getElementById('count').value=num;
num=num+1;
i=setTimeout("startCount()",1000);
}
function stopCount(){
clearTimeout(i);
}
</script>
</head>
<body>
<form>
<input type="text" id="count" />
<input type="button" value="Start" onclick="startCount()" />
<input type="button" value="Stop" onclick="stopCount()" />
</form>
</body>
</html>
1回答
-
- shuichengjian
- 2017-05-31 12:20:33
在函数 startCount()中插入 clearTimeout(i);
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>计时器</title>
<script type="text/javascript">
var num=0;
var i;
function startCount(){
clearTimeout(i);
document.getElementById('count').value=num;
num=num+1;
i=setTimeout("startCount()",1000);
}
function stopCount(){
clearTimeout(i);
}
</script>
</head>
<body>
<form>
<input type="text" id="count" />
<input type="button" value="Start" onclick="startCount()" />
<input type="button" value="Stop" onclick="stopCount()" />
</form>
</body>
</html>
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