Fetch remote image with xhr

xhrFetchImg.js

var url = 'https://static.mawenbao.com/images/cartoon/%E7%BB%88%E6%9C%AB%E7%9A%84%E4%BC%8A%E6%B3%BD%E5%A1%94.jpg';
var xhr = new XMLHttpRequest();
xhr.open('GET', url, false);
if (xhr.overrideMimeType) xhr.overrideMimeType('text/plain; charset=x-user-defined');
xhr.setRequestHeader("Content-Type", "application/octet-stream");

var txt = '';
function handle() {
    if (this.readyState != null && (this.readyState < 3 || this.status != 200)) {
        return
    }
    txt += this.responseText;
}
xhr.onreadystatechange = handle;

xhr.send(null);

var binArr = new Uint8Array(txt.length);
for (var i = 0; i < txt.length; i++) {
    binArr[i] = txt.charCodeAt(i);
}

var img = document.createElement('img');
img.src = window.URL.createObjectURL(new Blob([binArr]));
document.body.appendChild(img);