Cloud Storage for Firebase allows you to quickly and easily upload files to a
Cloud Storage
bucket provided
and managed by Firebase.
Create a Reference
To upload a file, first
create a Cloud Storage reference
to the file you want to upload.
You can create a reference by appending child paths to the root of your
Cloud Storage bucket, or you can create a reference from an existing
gs://
or
https://
URL referencing an object in Cloud Storage.
// Create a root reference
StorageReference storageRef = storage.RootReference;
// Create a reference to "mountains.jpg"
StorageReference mountainsRef = storageRef.Child("mountains.jpg");
// Create a reference to 'images/mountains.jpg'
StorageReference mountainImagesRef =
storageRef.Child("images/mountains.jpg");
// While the file names are the same, the references point to different files
Assert.AreEqual(mountainsRef.Name, mountainImagesRef.Name);
Assert.AreNotEqual(mountainsRef.Path, mountainImagesRef.Path);
You cannot upload data with a reference to the root of your
Cloud Storage bucket. Your reference must point to a child URL.
Upload Files
Once you have a reference, you can upload files to Cloud Storage
in two ways:
- Upload from a byte array in memory
- Upload from a file path representing a file on device
Upload from data in memory
The
PutBytesAsync()
method is the simplest way to upload a file to
Cloud Storage.
PutBytesAsync()
takes a byte[]
and returns a
System.Task<Firebase.Storage.StorageMetadata>
which will
contain information about the file when the task completes. You can optionally
use an
IProgress<UploadState>
(typically
StorageProgress<UploadState>
) to
monitor your upload status.
// Data in memory
var customBytes = new byte[] {
/*...*/
};
// Create a reference to the file you want to upload
StorageReference riversRef = storageRef.Child("images/rivers.jpg");
// Upload the file to the path "images/rivers.jpg"
riversRef.PutBytesAsync(customBytes)
.ContinueWith((Task<StorageMetadata> task) => {
if (task.IsFaulted || task.IsCanceled) {
Debug.Log(task.Exception.ToString());
// Uh-oh, an error occurred!
}
else {
// Metadata contains file metadata such as size, content-type, and md5hash.
StorageMetadata metadata = task.Result;
string md5Hash = metadata.Md5Hash;
Debug.Log("Finished uploading...");
Debug.Log("md5 hash = " + md5Hash);
}
});
Upload from a local file
You can upload local files on the devices, such as photos and videos from the
camera, with the
PutFileAsync()
method.
PutFileAsync()
takes a
string
representing the path to the file and returns a
System.Task<Firebase.Storage.StorageMetadata>
which will contain
information about the file when the task completes. You can optionally
use an
IProgress<UploadState>
(typically
StorageProgress<UploadState>
) to
monitor your upload status.
// File located on disk
string localFile = "...";
// Create a reference to the file you want to upload
StorageReference riversRef = storageRef.Child("images/rivers.jpg");
// Upload the file to the path "images/rivers.jpg"
riversRef.PutFileAsync(localFile)
.ContinueWith((Task<StorageMetadata> task) => {
if (task.IsFaulted || task.IsCanceled) {
Debug.Log(task.Exception.ToString());
// Uh-oh, an error occurred!
}
else {
// Metadata contains file metadata such as size, content-type, and download URL.
StorageMetadata metadata = task.Result;
string md5Hash = metadata.Md5Hash;
Debug.Log("Finished uploading...");
Debug.Log("md5 hash = " + md5Hash);
}
});
If you want to actively monitor your upload, you can use a
StorageProgress
class or your own class that implements
IProgress<UploadState>
, with the
PutFileAsync()
or
PutBytesAsync()
methods.
See
Manage Uploads
for more information.
You can also include metadata when you upload files. This metadata contains
typical file metadata properties such as
Name
,
Size
, and
ContentType
(commonly referred to as MIME type). The
PutFileAsync()
method automatically
infers the content type from the filename extension, but you can override the
auto-detected type by specifying
ContentType
in the metadata. If you do not
provide a
ContentType
and Cloud Storage cannot infer a default from
the file extension, Cloud Storage uses
application/octet-stream
. See
the
Use File Metadata
section for more information about file metadata.
// Create storage reference
StorageReference mountainsRef = storageRef.Child("images/mountains.jpg");
byte[] customBytes = new byte[] {
/*...*/
};
string localFile = "...";
// Create file metadata including the content type
var newMetadata = new MetadataChange();
newMetadata.ContentType = "image/jpeg";
// Upload data and metadata
mountainsRef.PutBytesAsync(customBytes, newMetadata, null,
CancellationToken.None); // .ContinueWithOnMainThread(...
// Upload file and metadata
mountainsRef.PutFileAsync(localFile, newMetadata, null,
CancellationToken.None); // .ContinueWithOnMainThread(...
Monitor Upload Progress
You can attach listeners to uploads in order to monitor the progress of the
upload. The listener follows the standard
System.IProgress<T>
interface. You can use an instance of the
StorageProgress
class, to provide
your own
Action<T>
as a callback for progress ticks.
// Start uploading a file
var task = storageRef.Child("images/mountains.jpg")
.PutFileAsync(localFile, null,
new StorageProgress<UploadState>(state => {
// called periodically during the upload
Debug.Log(String.Format("Progress: {0} of {1} bytes transferred.",
state.BytesTransferred, state.TotalByteCount));
}), CancellationToken.None, null);
task.ContinueWithOnMainThread(resultTask => {
if (!resultTask.IsFaulted && !resultTask.IsCanceled) {
Debug.Log("Upload finished.");
}
});
Error Handling
There are a number of reasons why errors may occur on upload, including
the local file not existing, or the user not having permission to upload
the desired file. You can find more information about errors in the
Handle Errors
section of the docs.
Next Steps
Now that you've uploaded files, let's learn how to
download them
from Cloud Storage.