根据图片的路径（绝对路径/相对路径都可以），生成base64的
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>nick getBase64</title>
</head>
<body>
<div><img id="test" src="" alt=""/></div>
<script src="jquery.min.js"></script>
<script>
// var imgSrc = "https://img.alicdn.com/bao/uploaded/TB1qimQIpXXXXXbXFXXSutbFXXX.jpg";
var imgSrc = "pic.jpg";
// var imgSrc = "img/1.jpg";
function getBase64(img){//传入图片路径，返回base64
function getBase64Image(img,width,height) {//width、height调用时传入具体像素值，控制大小 ,不传则默认图像大小
var canvas = document.createElement("canvas");
canvas.width = width ? width : img.width;
canvas.height = height ? height : img.height; var ctx = canvas.getContext("2d");
ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
var dataURL = canvas.toDataURL();
return dataURL;
}
var image = new Image();
image.crossOrigin = '';
image.src = img;
var deferred=$.Deferred();
if(img){
image.onload =function (){
deferred.resolve(getBase64Image(image));//将base64传给done上传处理
}
return deferred.promise();//问题要让onload完成后再return sessionStorage['imgTest']
}
}
getBase64(imgSrc)
.then(function(base64){
console.log(base64);
$("#test").attr("src",base64)
},function(err){
console.log(err);
});
</script>
</body>
</html>