本机javascript相当于jQuery .attr（...）。load（）？

Question

与下面的jquery等效的本机javascript是什么？

("<img/>").attr("src", "data:image/gif;base64," + base64).load(function() {
  context.scale(width/this.width,  height/this.height);
  context.drawImage(this, 0, 0); 
  deferred.resolve($("<img/>").attr("src", canvas.toDataURL()));               
});

Answer 1

类似的东西：

var img = document.createElement('image'),
    type = 'load',        
    callback = function () {
        context.scale(width/this.width,  height/this.height);
        context.drawImage(this, 0, 0); 
        deferred.resolve(img.setAttribute('src', canvas.toDataURL()));
    };

img.setAttribute('src', "data:image/gif;base64," + base64]);
if (img.addEventListener) {
    img.addEventListener(type, callback, false);
} else if (img.attachEvent) {
    img.attachEvent('on' + type, callback);
} else {
    img['on' + type] = callback;
}
// Add element into DOM
document.body.appendChild(img);