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.
Add File Metadata
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 .
