我正在尝试使用 facebook api 从我保存在页面上的画布上传图像:
var file = dataURItoBlob(canvas.toDataURL('image/jpeg', 1.0))
FB.api('/me/photos', 'POST', {
source: file,
message: 'photo description'
}, function (response) {
console.log(response)
}
)
这是 blob 转换器:
function dataURItoBlob(dataURI) {
var byteString = atob(dataURI.split(',')[1]);
var ab = new ArrayBuffer(byteString.length);
var ia = new Uint8Array(ab);
for (var i = 0; i < byteString.length; i++) {
ia[i] = byteString.charCodeAt(i);
}
return new Blob([ab], { type: 'image/jpeg' });
}
我收到一个错误:message: "(#324) Requires upload file"
所以上传者似乎无法将该 blob 识别为有效文件。
更新1:
我找到了这个帖子:将数据 URI 转换为文件,然后附加到 FormData关于将 blob 转换为 formData,尝试如下:
var dataURL = canvas.toDataURL('image/jpeg', 1.0)
var blob = dataURItoBlob(dataURL)
var fd = new FormData(document.forms[0])
fd.append("canvasImage", blob)
FB.api('/me/photos', 'POST', {
source: fd .....
但仍然是同样的错误。
更新2:
甚至尝试过这个 XHR post 解决方案,使用 Facebook 的 javascript api 发布多部分/表单数据编码图像仍然遇到文件问题"Your photos couldn't be uploaded. Photos should be less than 4 MB and saved as JPG, PNG, GIF or TIFF files."
function postImageToFacebook(access_token) {
var filename = "samplepic.png",
mimeType = "image/png",
message = "test comment",
data = canvas.toDataURL("image/png"),
encodedPng = data.substring(data.indexOf(',') + 1, data.length),
imageData = atob(encodedPng);
// build the multipart/form-data
var boundary = '----ThisIsTheBoundary1234567890';
var formData = '--' + boundary + '\r\n'
formData += 'Content-Disposition: form-data; name="source"; filename="' + filename + '"\r\n';
formData += 'Content-Type: ' + mimeType + '\r\n\r\n';
for (var i = 0; i < imageData.length; ++i) {
formData += String.fromCharCode(imageData[i] & 0xff);
}
formData += '\r\n';
formData += '--' + boundary + '\r\n';
formData += 'Content-Disposition: form-data; name="message"\r\n\r\n';
formData += message + '\r\n'
formData += '--' + boundary + '--\r\n';
var xhr = new XMLHttpRequest();
xhr.open( 'POST', 'https://graph.facebook.com/v2.5/me/photos?access_token=' + access_token, true );
xhr.onload = xhr.onerror = function() {
console.log( xhr.responseText );
};
xhr.setRequestHeader( "Content-Type", "multipart/form-data; boundary=" + boundary );
xhr.send( formData );
}