function convertImgToBase64(url, callback, outputFormat) {
var canvas = document.createElement('CANVAS'),
ctx = canvas.getContext('2d'),
img = new Image;
img.crossOrigin = 'Anonymous';
img.onload = function() {
canvas.height = img.height;
canvas.width = img.width;
ctx.drawImage(img, 0, 0);
var dataURL = canvas.toDataURL(outputFormat || 'image/png');
callback.call(this, dataURL);
canvas = null;
};
img.src = url;
}
convertImgToBase64('{$codeImg}', function(base64Img) {
// Base64DataURL
console.log(base64Img);
$("#code_img").attr('src', base64Img);
});
tips:这个有用的前提是,你请求的那端服务器允许跨域请求;如果使用oss存储,就是云盘,即使oss允许跨域请求,偶尔还是会加载失败,因为有缓存,所以,应该请求图片的时候加时间戳。