restarting a setInterval

问题

So I have a timer rotates a set of images ever 5 seconds. Therefore, I am running this upon document launch.

$(document).ready(function() {
var intervalID=setInterval(function(){ 
     rotate();    
}, 5000);
});

The Rotate function simply just rotates the images. However, I also allow the user to manually select what image they are looking at. Because of this I need to cancel the SetInterval and then start it over back at 5 seconds again

What I am trying to do is cancel the interval then start it over by doing this

$('a').click(function(){
 clearInterval(intervalID);   
 intervalID=setInterval(function(){ 
     rotate();    
}, 5000);    
});

However, the code doesn't seem to reset the interval like I had hoped.

回答1:

Just make intervalID be global variable by declaring it outside and above all functions.

With your current code its scope is limited to $(document).ready() method so it might cause the problem you describe.

回答2:

If the intervalID variable is declared within the .ready() scope, the following ought to work (untested):

$(document).ready(function() {
    var rotate = function() { ... },
        intervalID = setInterval(rotate, 5000);

    $('a').click(function() {
       clearInterval(intervalID);   
       intervalID = setInterval(rotate, 5000);    
    });
});

回答3:

Well, it looks like you are declaring interverID locally within the anonymous function from your .ready() handler. I'm actually wondering why you don't face a Reference error in your click-event handler, since intervalID cannot be known there.

You need to make sure that this variable is available and does have a shared context for both functions. Easiest way to go, create an anonymous self invoking method around your script and declare that variable out of scope.

(function _myPrivateContext($, window, document, undefined) {
    var intervalID = null;

    $(document).ready(function() {
       intervalID = setInterval(rotate, 5000);
    });

    $('a').click(function(){
        clearInterval(intervalID);   
        intervalID = setInterval(rotate, 5000);    
    });

}(jQuery, window, document));

来源：https://stackoverflow.com/questions/6856651/restarting-a-setinterval

标签

javascript

jquery

setinterval

clearinterval