// Set upload values
String filePath = "PATH TO LOCAL FILE TO BE UPLOADED";
String fileName = "FILE NAME TO UPLOAD AS";
String folderId = "FOLDER ID TO UPLOAD TO";

// Select Box folder
BoxFolder folder = new BoxFolder(api, folderId);

// Upload file
FileInputStream stream = new FileInputStream(filePath);
BoxFile.Info newFileInfo = folder.uploadFile(stream, fileName);
stream.close();

// Set upload values
var filePath = 'PATH TO LOCAL FILE TO BE UPLOADED';
var fileName = 'FILE NAME TO UPLOAD AS';
var folderId = 'FOLDER ID TO UPLOAD TO';

// Upload file
BoxFile newFile;
using(FileStream stream = new FileStream(filePath, FileMode.Open))
{
  BoxFileRequest req = new BoxFileRequest()
  {
    Name = fileName,
    Parent = new BoxRequestEntity(){ Id = folderId }
  };

  newFile = await client.FilesManager.UploadAsync(req, stream);
  Console.Out.Write(newFile.Id);
}

# Set upload values
file_path = 'PATH TO LOCAL FILE TO BE UPLOADED'
file_name = 'FILE NAME TO UPLOAD AS'
folder_id = 'FOLDER ID TO UPLOAD TO'

box_file = client.folder(folder_id).upload(file_path, file_name)

# Set upload values
filepath = 'PATH TO LOCAL FILE TO BE UPLOADED'
filename = 'FILE NAME TO UPLOAD AS'

# Select Box folder
folder = client.folder_from_path('/')

# Upload file
file = client.upload_file(filepath, folder, name: filename)

BOXFile *file = ... // A BOXFile that you retrieved through the Content SDK or Browse SDK. See the Sample Application for an example.
            BOXFilePreviewController *filePreviewController = [[BOXFilePreviewController alloc] initWithContentClient:[BOXContentClient defaultClient] file:file];
            [self.navigationController pushViewController:filePreviewController animated:YES completion:nil];

BoxPreviewActivity.IntentBuilder builder = BoxPreviewActivity.createIntentBuilder(this, boxSession, boxFile);