JavaScript Base64 作为文件上传的实例代码解析

思路：

　　第一步先把base64 转化成 Blob 对象 ；

　　第二步创建文件对象；

　　第三步将其作为文件上传。

直接上代码：

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title>上传用例</title>
    <meta content='width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no' name='viewport'>
    <script type="text/javascript">
        /**
         * 根据base64 内容 取得 bolb
         *
         * @param dataURI
         * @returns Blob
         */
        function getBlobBydataURI(dataURI,type) {
            var binary = atob(dataURI.split(',')[1]);
            var array = [];
            for(var i = 0; i < binary.length; i++) {
                array.push(binary.charCodeAt(i));
            }
            return new Blob([new Uint8Array(array)], {type:type });
        }
 
        /**
         * 上传
         */
        function upload(){
            //base64 转 blob
            var $Blob= getBlobBydataURI(document.getElementsByTagName("img")[0].currentSrc,'image/jpeg');
            var formData = new FormData();
            formData.append("files", $Blob ,"file_"+Date.parse(new Date())+".jpeg");
            注意：如果同时还要上传其他文件时可以直接append 到后面
            // formData.append("jsonText",content);
            // formData.append("scenename",dialog.getConfig().content.value);
            // formData.append("user","九七")
            //组建XMLHttpRequest 上传文件
            var request = new XMLHttpRequest();
 
            //上传连接地址
            request.open("POST", "http://127.0.0.1:8713/sceneManage/sceneSave");
            
            request.onreadystatechange=function()
            {
                if (request.readyState==4)
                {
                    if(request.status==200){
                        console.log("上传成功");
                    }else{
                        console.log("上传失败,检查上传地址是否正确");
                    }
                }
            }
            request.send(formData);
        }
 
    </script>
</head>
<body>
<button onclick="upload()">上传测试</button>
 
<br />
上传的图片:
<img src="data:image/jpeg;base64,/9j/4AAQSkZJRgABAQEAeAB4AAD/4QAiRXhpZgAATU0AKgAAAAgAAQESAAMAAAABAAEAAAAAAAD/2wBDABsSFBcUERsXFhceHBsgKEIrKCUlKFE6PTBCYFVlZF9VXVtqeJmBanGQc1tdhbWGkJ6jq62rZ4C8ybqmx5moq6T/wAALCABQADEBAREA/8QAGgAAAwADAQAAAAAAAAAAAAAAAwQFAAECBv/EADQQAAIBAwMCAgcGBwAAAAAAAAECAwAEEQUSITFBE1EVImFxgaHwBiMykbHRFEJDcoKiwf/aAAgBAQAAPwD0tc5AGc1MuftBYW7FfEMrDtGM/Ohp9pbNmUNHOgbo7qAP1p60vra8z4E6uR1HcfCmVrKHc3EdrBJNI2FUZNSIreXWR41w7xW38kSnBYebe/686o2ljaWwPgQxqemRyT8aO8UTqVeJWHkQKlzaHDuaS0Y28/VSh9X3EeX17KNpWoPc+Lb3KBLiDhwOhHmKo5qPqY9Iajb6eM+Go8aX2jsK71dmhW2tIcxrcSCNivUKeuKnw2mnyXc1rbJcRzxAnxd/UijwajdXkVlbrIqSXCsXkA5wCRx7eDQ7i4i024KxXV3PMuGKytlD8vLP5UfUHCXunaimVEuEYDqQeRVmpthg61qjHqPDH+p/anL+0F1Eu1gskbB42Izhh0pA2mqSho3a1h38PLGvrMK3Ppj24tpbHBktl2hWON47/Hmg3FnPduxbThbyyDa0xlDBR34HsouvRCLSIYlOdjoo+FP+tU6+b0Zq63pH3E6iOU4/Cex+VWI5FkUMrAg9CO9BvEnlgZLaURy54YjOKniy1sHPpKM/4D9qqqWCgOctgZ46mpN4w1HWLe1TlLY+LIfb2FWKHPBHcxtHKgZWGCCKi2y3FnqbWdlJ40CgM6yf0xnoD9frV+sqPrt1eWsG6EbIzgNL3XnsPr/tOaXZQWduFhbfv9ZnPVj503trrApeG0hgllkiTa0xzIck5P0TTGKzFDmhjnieKRdyOMMOmayGJIYkijXaqDCjOcCi1ql5ruGGQRt4hcjdhI2fj4A1w2oQqMsJ1Hm1vIB+eKJLdRQuElbYCMh24X3Z86WXWLJtv3yDchfl14x2PPWmra4juYEmiIKsM9c49nvo9aqXdyPHf+LGWXbHsObeSQdc8YwPnS5vnvrdgk6uN2DttJOx8wTinJ3dZFmhuCrSIQscqHacc5x1HGaQWYiaFI2UoYWCsLSX8ORwBu5B8/3qrpxJs4zuRlx6hQEAr24PNN1qlXhlnkKykCDPCLzv/uPl7Pn2ocVm8UZKSBJd7MGAyCCxIBHfrW/4eaa4Es2xQIigCknDE8noOwFci0mjeAwyIPCgMW5lJycr2yPI96ZtIBbWscAbdsUDPnR6/9k=" />
</body>
</html>

 

转载于:https://www.cnblogs.com/wx790868181/p/11041969.html

posted @ 2021-01-18 15:57  虚无——缥缈  阅读(325)  评论(0)  编辑  收藏  举报