我正在做网络应用程序.要上传图像我使用Blob,以防万一BlobBuilder. Blob运行良好,但Blob不适用于Android原生浏览器,Android原生浏览器使用BlobBuilder.我预计,Blob和BlobBuilder返回相同的blob,但他们没有.这是我的代码：
base64toBlob: function(b64Data,contentType,sliceSize) {
var BlobBuilder,blob,byteArray,byteCharacters,byteNumbers,charCodeFromCharacter,err,posIndex;
if (contentType == null) {
contentType = '';
}
if (sliceSize == null) {
sliceSize = 1024;
}
posIndex = b64Data.indexOf('base64,');
if (posIndex !== -1) {
b64Data = b64Data.substring(posIndex + 7);
}
charCodeFromCharacter = function(c) {
return c.charCodeAt(0);
};
byteCharacters = atob(b64Data.replace(/\s/g,''));
byteNumbers = Array.prototype.map.call(byteCharacters,charCodeFromCharacter);
byteArray = new Uint8Array(byteNumbers);
try {
blob = new Blob([byteArray.buffer],{
type: contentType
});
return blob;
} catch (_error) {
err = _error;
BlobBuilder = window.BlobBuilder || window.WebKitBlobBuilder || window.MozBlobBuilder;
blob = new BlobBuilder();
blob.append(byteArray.buffer);
return blob.getBlob(contentType);
}
}
我发送请求时做了日志
blobImg = base64toBlob(base64Data,imageType);
alert(JSON.stringify(blobImg));
// alert shows {"type": "image/jpeg","size": 10251 } when blob worked
// alert shows {"type": "image/jpeg","size": 27822 } when blobbuilder worked
ajaxRequest.send(blobImg);
我尝试在所有浏览器上以相同的图像上传.在Chrome和其他浏览器上,我从log {“type”：“image / jpeg”,“size”：10251}获取并请求发送成功,但在Android原生浏览器上我得到{“type”：“image / jpeg”,“大小“：27822}并且请求失败,状态码为0.在android浏览器上工作catch部分(我猜,这意味着Android本机浏览器不支持Blob)我在android 4.1.2中测试过.我从谷歌没有发现任何问题.我很高兴如果有人帮助我！
解决方法
try {
blob = new Blob([byteArray.buffer],{ // use of .buffer
type: contentType
});
return blob;
} catch (_error) {
err = _error;
BlobBuilder = window.BlobBuilder || window.WebKitBlobBuilder || window.MozBlobBuilder;
blob = new BlobBuilder();
blob.append(byteArray); // just uses the raw array
return blob.getBlob(contentType);
}
从MDN documentation开始BlobBuilder.append：
Appends the contents of the specified JavaScript object to the
Blob
being built. If the value you specify isn’t aBlob,ArrayBuffer,or
String,the value is coerced to a string before being appended to the
blob.
byteArray不是ArrayBuffer类型,所以它可能被强制转换为字符串.您可以通过将其转换为字符串并检查其长度来自行确认.要修复它,只需在catch块中使用byteArray.buffer.
有趣的是,Blob constructor 似乎直接接受了一个ArrayBufferView,你的Uint8Array就是这个.这可能意味着你在这种情况下实际上并不需要.buffer,尽管我对API的熟悉程度不够高.
