1. 程式人生 > >javascript base64 作為檔案上傳。

javascript base64 作為檔案上傳。

例如我們用某些 裁剪外掛 得到的圖片是
<ing src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAAkCAYAAABIdFAMAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAAHhJREFUeNo8zjsOxCAMBFB/ KEAUFFR0Cbng3nQPw68ArZdAlOZppPFIBhH5EAB8b+Tlt9MYQ6i1BuqFaq1CKSVcxZ2Acs6406KUgpt5/ LCKuVgz5BDCSb13ZO99ZOdcZGvt4mJjzMVKqcha68iIePB86GAiOv8CDADlIUQBs7MD3wAAAABJRU5ErkJggg==">

這樣的,那這樣的檔案怎樣在from 表單上傳(當然我是舉例,大部分的裁剪外掛都是有內建的)

首先需要 吧 base64 流轉換成 blob 物件,檔案物件都繼承它。

函式如下:

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 });
}

那麼剩下的就作為檔案上傳就ok
var $Blob= getBlobBydataURI(base64Data,'image/png');
var formData = new FormData();
formData.append("files", $Blob ,"file_"+Date.parse(new Date())+".png");
全部程式碼是這樣子的:
<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title>上傳用例</title>
    <meta content='width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no' name='viewport'>
    <script type="text/javascript">
        /**
         * 根據base64 內容 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 });
        }

        /**
         * 上傳
         */
        function upload(){
            //base64 轉 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");
            //組建XMLHttpRequest 上傳檔案
            var request = new XMLHttpRequest();

            //上傳連線地址
            request.open("POST", "www.xxx.com");
            
            request.onreadystatechange=function()
            {
                if (request.readyState==4)
                {
                    if(request.status==200){
                        console.log("上傳成功");
                    }else{
                        console.log("上傳失敗,檢查上傳地址是否正確");
                    }
                }
            }
            request.send(formData);
        }

    </script>
</head>
<body>
<button onclick="upload()">上傳測試</button>

<br />
上傳的圖片:
<img src="data:image/jpeg;base64,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" />
</body>
</html>