curl -X POST https://upload.box.com/api/2.0/files/content \
     -H 'Authorization: Bearer <ACCESS_TOKEN>'
     -H "Content-Type: multipart/form-data" \
     -F attributes='{"name":"Photo.jpg", "parent":{"id":"11446498"}}' \
     -F file=@<FILE_NAME>

using (FileStream fileStream = new FileStream(filePath, FileMode.Open))
{
    BoxFileRequest requestParams = new BoxFileRequest()
    {
        Name = uploadFileName,
        Parent = new BoxRequestEntity() { Id = "0" }
    };

    BoxFile file = await client.FilesManager.UploadAsync(requestParams, fileStream);
}

BoxFolder rootFolder = BoxFolder.getRootFolder(api);
FileInputStream stream = new FileInputStream("My File.txt");
BoxFile.Info newFileInfo = rootFolder.uploadFile(stream, "My File.txt");
stream.close();

folder_id = '22222'
new_file = client.folder(folder_id).upload('/home/me/document.pdf')
print('File "{0}" uploaded to Box with file ID {1}'.format(new_file.name, new_file.id))

var fs = require('fs');
var stream = fs.createReadStream('/path/to/My File.pdf');
var folderID = '0'
client.files.uploadFile(folderID, 'My File.pdf', stream)
	.then(file => {
		/* file -> {
			total_count: 1,
			entries: 
			[ { type: 'file',
				id: '11111',
				file_version: 
					{ type: 'file_version',
					id: '22222',
					sha1: '0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33' },
				sequence_id: '0',
				etag: '0',
				sha1: '0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33',
				name: 'My File.pdf',
				description: '',
				size: 68431,
				path_collection: 
					{ total_count: 1,
					entries: 
					[ { type: 'folder',
						id: '0',
						sequence_id: null,
						etag: null,
						name: 'All Files' } ] },
				created_at: '2017-05-16T15:18:02-07:00',
				modified_at: '2017-05-16T15:18:02-07:00',
				trashed_at: null,
				purged_at: null,
				content_created_at: '2017-05-16T15:18:02-07:00',
				content_modified_at: '2017-05-16T15:18:02-07:00',
				created_by: 
					{ type: 'user',
					id: '33333',
					name: 'Test User',
					login: 'test@example.com' },
				modified_by: 
					{ type: 'user',
					id: '33333',
					name: 'Test User',
					login: 'test@example.com' },
				owned_by: 
					{ type: 'user',
					id: '33333',
					name: 'Test User',
					login: 'test@example.com' },
				shared_link: null,
				parent: 
					{ type: 'folder',
					id: '0',
					sequence_id: null,
					etag: null,
					name: 'All Files' }
				item_status: 'active' } ] }
		*/
	});

let data = "test content".data(using: .utf8)

let task: BoxUploadTask = client.files.upload(data: data, name: "Test File.txt", parentId: "0") { (result: Result<File, BoxSDKError>) in
    guard case let .success(file) = result else {
        print("Error uploading file")
        return
    }

    print("File \(file.name) was uploaded at \(file.createdAt) into \"\(file.parent.name)\"")
}

// To cancel upload
if someConditionIsSatisfied {
    task.cancel()
}