while 循环内的 setTimeout [英] setTimeout inside while loop

问题描述

我已经搜索了如何将 setTimeOut 与 for 循环一起使用，但是关于如何将它与 while 循环一起使用的内容并不多，而且我不明白为什么应该有很多反正有区别.我编写了以下代码的一些变体，但此循环似乎会使浏览器崩溃:

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，其源属性有时需要时间来加载，所以在我可以显示它之前，我需要不断检查它是否已加载，并且仅当它的路径在 $ 中可用时('#currentImage')，然后我显示它.

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.

这段代码在我使用 while 循环之前运行良好，当我直接使用时

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);

但我不想让用户等待 3 秒，如果加载速度可能会更快，因此我将 setTimeOut 放在一个 while 循环中并缩短其间隔，以便我每半秒只检查加载的路径.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:

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while 循环内的 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！