加载图片

function loadImg(src, callback) {
var imgs = new Image();
var firstload = "yes";

imgs.onload = function () {
if (firstload == "yes") {
imgs.onload = null;
callback(imgs);
firstload = "no";
}
}
imgs.src = src;

if (imgs.complete) {
console.log("img complete");
return;
}
}