javascript - 用JS判断图片404/filesize

Question

我在 JS 中有这个预加载图像的功能:

// http://stackoverflow.com/questions/3646036/javascript-preloading-images
var preloaded_images = [];
function preload() {
    for (i = 0; i < arguments.length; i++) {
        preloaded_images[i] = new Image();
        preloaded_images[i].src = preload.arguments[i];
    }
}

但是，我尝试预加载的某些图像会抛出 404 错误。如何在不尝试将图像添加到 DOM 的情况下在此函数中检测到 404？

Answer 1

您可以附加 onerror 事件处理程序:

...
preloaded_images[i].onerror = function() {
    // the image couldn't be loaded..
}
...

如果你想知道它是否加载成功，你会这样做:

...
preloaded_images[i].onload = function() {
    // the image was loaded successful..
}
... 

Fiddle