Solution to onload event execution after I add the img element only to the document _ javascript tips-js tutorial

If the img element is not added to the document after it is created, the onload event will be executed. For more information, see. Example

The Code is as follows:

The onload event is executed only when the img element is created but not added to the document.


Script
Var img = document. createElement ('img ');
Img. src = "http://www.sinaimg.cn/rny/sinamail57/skins/110318/17/logo.jpg ";
Img. onload = function () {alert (this. width );};
Script

Iframe and script must be added to the document before callback is executed.