[英]Javascript clearInterval with interval Id doesn't work in react js
[英]Reset countdown interval with clearInterval doesn't work
我不知道如何重置正在进行的计数器。 我的页面上有两个柜台。 看来它工作正常,但是当我想在仍要递减计数的情况下为counter2设置新值时,我在div中看到了两个计数时间。 新老。
var interval1;
var interval2;
function countdown(element, minutes, seconds, timer) {
var el = document.getElementById(element);
clearInterval(timer);
timer = setInterval(function() {
if(seconds == 0) {
if(minutes == 0) {
(el.innerHTML = "---");
clearInterval(timer);
return;
}
else {
minutes--;
seconds = 60;
}
}
if(minutes > 0) {
var minute_text = minutes + (minutes > 1 ? ' minutes' : ' minute');
}
else {
var minute_text = '';
}
var second_text = seconds > 1 ? '' : '';
el.innerHTML = minute_text + ' ' + seconds + ' ' + second_text + '';
seconds--;
}, 1000);
}
function setCounter1(mins) {
countdown('timeLeft', mins, 00, interval1);
}
function setCounter2(mins) {
countdown('timeLeft2', mins, 00, interval2);
}
例如,如果我将counter2设置为10分钟,并且在一分钟后调用setCounter2(3),则在timeLeft2 div中会看到两个计数器。
如何重置正在进行的计数器?
谢谢你的帮助!
在函数内部重新分配参数变量不会在函数外部修改参数。 您可以在这里看到该事实的演示: http : //jsfiddle.net/t6z5324y/
var outsideVariable = 0;
console.log('start', outsideVariable);
function foo(insideVariable) {
console.log('before', insideVariable);
insideVariable = 1;
console.log('before', insideVariable);
}
foo(outsideVariable);
console.log('end', outsideVariable);
但是您可以将一个对象作为参数传递,并在函数内部修改该对象的成员。 解决方案将是:
var intervalHolder1 = {timer: null};
var intervalHolder2 = {timer: null};
function countdown(element, minutes, seconds, timerHolder) {
//stuff
clearInterval(timerHolder.timer);
timerHolder.timer = setInterval(function() {
//stuff
}, 1000);
}
function setCounter1(mins) {
countdown('timeLeft', mins, 00, intervalHolder1);
}
function setCounter2(mins) {
countdown('timeLeft2', mins, 00, intervalHolder2);
}
我可以通过在外部定义一个Interval数组(需要多少个)并让您的函数传递Interval的索引而不是Interval本身来做到这一点。
var interval1;
var interval2;
var arrayInterval = [interval1, interval2];
function countdown(element, minutes, seconds, timerId) {
var el = document.getElementById(element);
clearInterval(arrayInterval[timerId]);
arrayInterval[timerId] = setInterval(function() {
if (seconds == 0) {
if (minutes == 0) {
(el.value = "---");
clearInterval(arrayInterval[timerId]);
return;
} else {
minutes--;
seconds = 60;
}
}
if (minutes > 0) {
var minute_text = minutes + (minutes > 1 ? ' minutes' : ' minute');
} else {
var minute_text = '';
}
var second_text = seconds > 1 ? '' : '';
el.value = minute_text + ' ' + seconds + ' ' + second_text + '';
seconds--;
}, 1000);
}
function setCounter1(mins) {
countdown('timeLeft', mins, 00, 0);
}
function setCounter2(mins) {
countdown('timeLeft2', mins, 00, 1);
}
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