Hope to be able to monitor the loading completion action of each file and the loading completion action of all files.
Or you can provide a solution, that is, how can I load resources without using tools? I have only used the following method, which feels a bit stupid:
var img = new Image();
img.src = 'xxx';
img.onload = function(){}
Recommended to use Dropzone.js. Currently, one of our products needs to implement the upload preview function of pictures, videos, etc. I chose dropzone after looking at many plug-ins. Prepload is indeed a bit painful