我正在尝试通过javascript上传pdf文件。我有该文件的base64表示，我解码它。文件已上传，但该数据似乎已损坏。
当我尝试打开文件时，错误消息显示“文件已损坏且无法修复”。
我得到了base64字符串服务器端...
byte[] buffer = new byte[length];
var postedFile = httpRequest.Files[file];
postedFile.InputStream.Read(buffer, 0, length);
string encodedString = Convert.ToBase64String(buffer);
这是我上传文件的ajax调用
var data= Base64.decode(result); //result is the base64 encoded string
$.ajax({
url: url,
type: "POST",
data: data,
processData: false,
headers: {
"accept": "application/json;odata=verbose",
"X-RequestDigest": _digetsValue,
"content-length": length
},
success: function (data)
{
alert("it worked");
},
error: function (err)
{
}
});
对于解码，我正在使用这段代码...... 或者从这里How can you encode a string to Base64 in JavaScript?
var Base64 = {
// private property
_keyStr: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
// public method for encoding
encode: function (input)
{
var output = "";
var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
var i = 0;
input = Base64._utf8_encode(input);
while (i < input.length)
{
chr1 = input.charCodeAt(i++);
chr2 = input.charCodeAt(i++);
chr3 = input.charCodeAt(i++);
enc1 = chr1 >> 2;
enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
enc4 = chr3 & 63;
if (isNaN(chr2))
{
enc3 = enc4 = 64;
} else if (isNaN(chr3))
{
enc4 = 64;
}
output = output +
Base64._keyStr.charAt(enc1) + Base64._keyStr.charAt(enc2) +
Base64._keyStr.charAt(enc3) + Base64._keyStr.charAt(enc4);
}
return output;
},
// public method for decoding
decode: function (input)
{
var output = "";
var chr1, chr2, chr3;
var enc1, enc2, enc3, enc4;
var i = 0;
input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
while (i < input.length)
{
enc1 = Base64._keyStr.indexOf(input.charAt(i++));
enc2 = Base64._keyStr.indexOf(input.charAt(i++));
enc3 = Base64._keyStr.indexOf(input.charAt(i++));
enc4 = Base64._keyStr.indexOf(input.charAt(i++));
chr1 = (enc1 << 2) | (enc2 >> 4);
chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
chr3 = ((enc3 & 3) << 6) | enc4;
output = output + String.fromCharCode(chr1);
if (enc3 != 64)
{
output = output + String.fromCharCode(chr2);
}
if (enc4 != 64)
{
output = output + String.fromCharCode(chr3);
}
}
output = Base64._utf8_decode(output);
return output;
},
// private method for UTF-8 encoding
_utf8_encode: function (string)
{
string = string.replace(/\r\n/g, "\n");
var utftext = "";
for (var n = 0; n < string.length; n++)
{
var c = string.charCodeAt(n);
if (c < 128)
{
utftext += String.fromCharCode(c);
}
else if ((c > 127) && (c < 2048))
{
utftext += String.fromCharCode((c >> 6) | 192);
utftext += String.fromCharCode((c & 63) | 128);
}
else
{
utftext += String.fromCharCode((c >> 12) | 224);
utftext += String.fromCharCode(((c >> 6) & 63) | 128);
utftext += String.fromCharCode((c & 63) | 128);
}
}
return utftext;
},
// private method for UTF-8 decoding
_utf8_decode: function (utftext)
{
var string = "";
var i = 0;
var c = c1 = c2 = 0;
while (i < utftext.length)
{
c = utftext.charCodeAt(i);
if (c < 128)
{
string += String.fromCharCode(c);
i++;
}
else if ((c > 191) && (c < 224))
{
c2 = utftext.charCodeAt(i + 1);
string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
i += 2;
}
else
{
c2 = utftext.charCodeAt(i + 1);
c3 = utftext.charCodeAt(i + 2);
string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
i += 3;
}
}
return string;
}
}
最初，我正在做这样的事情......
getFileBuffer = function (file)
{
var deferred = $.Deferred();
var reader = new FileReader();
reader.onload = function (e)
{
deferred.resolve(e.target.result);
}
reader.onerror = function (e)
{
deferred.reject(e.target.error);
}
reader.readAsArrayBuffer(file);
return deferred.promise();
};
但当然这是HTML5和诸如此类的独家。所以，当我打电话给我的ajax函数时，我会从文件阅读器传入这个数组缓冲区，瞧！它会工作。现在我试图模仿IE8的相同功能。这可能吗？
由于
答案 0 :(得分：0)
前段时间我写了一些函数我认为是二进制安全的，这里有相关的功能; base64To6和（可能名称不当）base6To8。
var chars = (
'ABCDEFGHIJKLMNOPQRSTUVWXYZ' +
'abcdefghijklmnopqrstuvwxyz' +
'0123456789+/'
),
inver = {}, i;
for (i = 0; i < chars.length; ++i) {
inver[chars[i]] = i;
}
function base64To6(b64) {
var arr6 = [],
i = b64.length, lenMod = 0;
while (b64.charAt(--i) === '=')
++lenMod;
for (i = 0; i < b64.length - lenMod; ++i)
arr6.push(inver[b64.charAt(i)]);
i = b64.length & 3;
if (i) i = 4 - i;
i = i + b64.length;
arr6.byteLength = 3 * i / 4 - lenMod;
return arr6;
}
function base6To8(arr6) {
var arr8 = [], i,
e1, e2, e3,
s1, s2, s3, s4,
d1, d2, d3, d4;
for (i = 0; i < arr6.length; i += 4) {
s1 = (d1 = arr6[i] ) & 63;
s2 = (d2 = arr6[i + 1]) & 63;
s3 = (d3 = arr6[i + 2]) & 63;
s4 = (d4 = arr6[i + 3]) & 63;
// xxxxxx xxyyyy yyyyzz zzzzzz
e1 = ( s1 << 2) + (s2 >>> 4);
e2 = ((s2 & 15) << 4) + (s3 >>> 2);
e3 = ((s3 & 3) << 6) + s4 ;
arr8.push(e1);
if (d3 !== undefined)
arr8.push(e2, e3);
else if (d2 !== undefined )
arr8.push(e2);
}
if (arr6.byteLength !== undefined)
arr8.length = +arr6.byteLength;
return arr8;
}
现在，如果你这样做
var int8arr = base6to8(base64to6(data));
您将拥有整数的数组（最多8位数字）， Base64 代表。 JavaScript 不会将 Int8 用于 Number ，因此您无法立即使用此数组。
不幸的是，据我所知， IE8 不支持UInt8Array或Blob，这样可以让您愉快地使用二进制数据，所以我就是不确定你想从哪里拿到它。