希望这对其他人有帮助:)
// Download a file form a url.
function saveFile(url) {
// Get file name from url.
var filename = url.substring(url.lastIndexOf("/") + 1).split("?")[0];
var xhr = new XMLHttpRequest();
xhr.addEventListener("load", transferComplete);
xhr.addEventListener("error", transferFailed);
xhr.addEventListener("abort", transferCanceled);
xhr.responseType = 'blob';
xhr.onload = function() {
var a = document.createElement('a');
a.href = window.URL.createObjectURL(xhr.response); // xhr.response is a blob
a.download = filename; // Set the file name.
a.style.display = 'none';
document.body.appendChild(a);
a.click();
delete a;
if (this.status === 200) {
// `blob` response
console.log(this.response);
var reader = new FileReader();
reader.onload = function(e) {
var auth = firebase.auth();
var storageRef = firebase.storage().ref();
var metadata = {
'contentType': 'image/jpeg'
};
var file = e.target.result;
var base64result = reader.result.split(',')[1];
var blob = b64toBlob(base64result);
console.log(blob);
var uploadTask = storageRef.child('images/' + filename).put(blob, metadata);
uploadTask.on('state_changed', null, function(error) {
// [START onfailure]
console.error('Upload failed:', error);
// [END onfailure]
}, function() {
console.log('Uploaded',uploadTask.snapshot.totalBytes,'bytes.');
console.log(uploadTask.snapshot.metadata);
var download = uploadTask.snapshot.metadata.downloadURLs[0];
console.log('File available at', download);
// [START_EXCLUDE]
document.getElementById('linkbox').innerHTML = '<a href="' + download + '">Click For File</a>';
// [END_EXCLUDE]
});
// `data-uri`
};
reader.readAsDataURL(this.response);
};
};
xhr.open('GET', url);
xhr.send();
}
function b64toBlob(b64Data, contentType, sliceSize) {
contentType = contentType || '';
sliceSize = sliceSize || 512;
var byteCharacters = atob(b64Data);
var byteArrays = [];
for (var offset = 0; offset < byteCharacters.length; offset += sliceSize) {
var slice = byteCharacters.slice(offset, offset + sliceSize);
var byteNumbers = new Array(slice.length);
for (var i = 0; i < slice.length; i++) {
byteNumbers[i] = slice.charCodeAt(i);
}
var byteArray = new Uint8Array(byteNumbers);
byteArrays.push(byteArray);
}
var blob = new Blob(byteArrays, {type: contentType});
return blob;
}
function transferComplete(evt) {
window.onload = function() {
// Sign the user in anonymously since accessing Storage requires the user to be authorized.
auth.signInAnonymously().then(function(user) {
console.log('Anonymous Sign In Success', user);
document.getElementById('file').disabled = false;
}).catch(function(error) {
console.error('Anonymous Sign In Error', error);
});
}
}
function transferFailed(evt) {
console.log("An error occurred while transferring the file.");
}
function transferCanceled(evt) {
console.log("The transfer has been canceled by the user.");
}