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 function handleSave () { //导出base64格式的图片数据 var mycanvas = document.getElementById("mycanvas"); var base64Data = mycanvas.toDataURL("image/jpeg", 1.0); //封装blob对象 var blob = dataURItoBlob(base64Data); //组装formdata var fd = new FormData(); fd.append("fileData", blob);//fileData为自定义 fd.append("fileName", "123jpg");//fileName为自定义，名字随机生成或者写死，看需求 //ajax上传，ajax的形式随意，JQ的写法也没有问题 //需要注意的是服务端需要设定，允许跨域请求。数据接收的方式和 上传的文件没有区别 var xmlHttp = new XMLHttpRequest(); xmlHttp.open("POST", “你发送上传请求的url”); xmlHttp.setRequestHeader("Authorization", 'Bearer ' + localStorage.token);//设置请求header,按需设定，非必须 xmlHttp.send(fd); //ajax回调 xmlHttp.onreadystatechange = () => { //todo your code... }; }; function dataURItoBlob (base64Data) { var byteString; if (base64Data.split(',')[0].indexOf('base64') >= 0) byteString = atob(base64Data.split(',')[1]); else byteString = unescape(base64Data.split(',')[1]); var mimeString = base64Data.split(',')[0].split(':')[1].split(';')[0]; var ia = new Uint8Array(byteString.length); for (var i = 0; i < byteString.length; i++) { ia[i] = byteString.charCodeAt(i); } return new Blob([ia], {type: mimeString}); };

 function b64ToUint8Array(b64Image) { var img = atob(b64Image.split(',')[1]); var img_buffer = []; var i = 0; while (i < img.length) { img_buffer.push(img.charCodeAt(i)); i++; } return new Uint8Array(img_buffer); } var b64Image = canvas.toDataURL('image/jpeg'); var u8Image = b64ToUint8Array(b64Image); var formData = new FormData(); formData.append("image", new Blob([ u8Image ], {type: "image/jpg"})); var xhr = new XMLHttpRequest(); xhr.open("POST", "/api/upload", true); xhr.send(formData);