Base64-无效的编码

Question

I try to convert my image binary to base64 using this code but still not successful.

I got invalid base64 string. Verify using this tool.

http://www.freeformatter.com/base64-encoder.html

var img = document.getElementById('image');

function getBase64Image(img) {
var canvas = document.createElement("canvas");
canvas.width = img.width;
canvas.height = img.height;
var ctx = canvas.getContext("2d");
ctx.drawImage(img, 0, 0);
var dataURL = canvas.toDataURL("image/png");
return dataURL.replace(/^data:image\/(png|jpg);base64,/, "");
}

These solutions not helping me at all. I hope can get the answer soon.

• How to convert image into base64 string using javascript
• How to convert an image to base64 in JavaScript
• Convert image to base64 without canvas

Result +mdHoAAAAASUVORK5CYII=

Thanks.

Answer 1

I got the answer.

var img = document.getElementById('image');

var oReq = new XMLHttpRequest();
oReq.open("GET", img, true);
oReq.responseType = "arraybuffer";

oReq.onload = function (oEvent) {
    var arrayBuffer = oReq.response; // Note: not oReq.responseText
    if (arrayBuffer) {
        var x = img.split('.');
        var ext = x[x.length - 1];
        var b64img = _arrayBufferToBase64(arrayBuffer);
        $('<img />').attr('src', 'data:image/' + ext + ';base64,' + b64img).appendTo($('body'));
    }
};

oReq.send(null);

function _arrayBufferToBase64(buffer) {
    var binary = ''
    var bytes = new Uint8Array(buffer)
    var len = bytes.byteLength;
    for (var i = 0; i < len; i++) {
        binary += String.fromCharCode(bytes[i])
    }
    return window.btoa(binary);
}