循环中的setTimeout [英] setTimeout inside while loop

问题描述

我已经在for循环中搜索了如何使用 setTimeOut ，但是对于如何在while循环中使用它并没有很多，而且我没有看看为什么反正会有很多不同。我已经写了以下代码的一些变体，但是这个循环似乎使浏览器崩溃：

I've searched for how to use setTimeOut with for loops, but there isn't a lot on how to use it with while loops, and I don't see why there should be much difference anyway. I've written a few variations of the following code, but this loop seems to crash the browser:

while(src == '')
{ 
    (function(){
        setTimeout(function(){
        src = $('#currentImage').val();
        $("#img_"+imgIdx).attr('src',src);
        }, 500);
     });
} 

为什么？

基本上我有一个动态创建的图像，其源属性有时需要加载，所以在我显示它之前，我需要继续检查它是否已加载，并且只有当它的路径在 $（'＃currentImage'）中可用时，我才能显示它。

Basically I have an image created dynamically whose source attribute takes time to load at times, so before I can display it, I need to keep checking whether it's loaded or not, and only when its path is available in $('#currentImage'), then do I display it.

在我使用while循环之前，此代码工作正常，当我直接执行时

This code worked fine before I used a while loop, and when I directly did

setTimeout(function(){
    src = $('#currentImage').val();
    $("#img_"+imgIdx).attr('src',src);
}, 3000);

但是我不想让用户等待3秒如果加载可能会完成更快，因此我将 setTimeOut 放入while循环并缩短其间隔，以便我每半秒检查一次加载的路径。这有什么问题？

But I don't want to have to make the user wait 3 seconds if the loading might be done faster, hence I put the setTimeOut in a while loop and shorted its interval, so that I only check for the loaded path every half second. What's wrong with that?

推荐答案

谢谢大家 - 所有的建议都有帮助。最后我使用了setInterval，如下所示：

Thanks everyone - all the suggestions helped. In the end I used setInterval as follows:

var timer;
// code generating dynamic image index and doing ajax, etc
var checker = function() {
    var src = $('#currentImage').val();
    if(src !== '') {
    $('#img_' + imgIdx).attr('src', src);
        clearInterval(timer);
    }
};

timer = setInterval(checker, 500);  

这篇关于循环中的setTimeout的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！