Javascript setInterval clearInterval简单示例不工作解释? [英] Javascript setInterval clearInterval Simple Example Not Working Explained?
问题描述
我有一个非常简单的JS setInterval和clearInterval示例,它不起作用。必须有一个潜在的原因,为什么它不起作用,我想知道为什么:
I have a very simple JS setInterval and clearInterval example that doesn't work. There has got to be an underlying reason why it does not work and I would like to know why that is:
var automessage;
function turnON() //executed by onclick event A
{
var automessage = setInterval(function(){ something() }, 2000);
}
function turnOff() //executed by onclick event B
{
clearInterval(automessage);
}
function something()
{
//pulls instant messages
}
在此示例中,最终用户单击按钮以启动定时间隔过程,单击另一个按钮以停止定时间隔过程,然后再次单击打开按钮再次开始这个过程。从本质上讲,它将是一个开/关风格的过程。
In this example, an end-user clicks a button to start a timed interval process, clicks another button to stop the timed interval process, and then clicks the on button again to start the process again. Essentially, it would be an on/off styled process.
这不起作用,我试图找出原因。我可以使Stackoverflow上提供的所有其他数百个示例都可以工作,但我真的需要一个开/关样式的进程,不仅限于on,然后off。 setInterval应该可以随时打开和关闭。
This doesn't work and I am trying to figure out why. I can make all of the hundreds of other examples offered on Stackoverflow to work, but I really need an on/off styled process that isn't limited to just on, and then off. The setInterval should be able to turn on and off at any time.
我非常感谢任何人的帮助。另外,我不使用任何Jquery库。
I really appreciate anyone's help. Also, I do not use any Jquery libraries.
推荐答案
automessage
是声明两次 - 作为全局变量和局部变量。尝试:
automessage
is declared twice - as a global variable and as a local variable. try:
function turnON() //executed by onclick event A
{
automessage = setInterval(function(){ something() }, 2000);
}
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