Google drive v3 File list full console example

GoogleDriveV3FileListConsoleExample.cs

using System;
using System.IO;
using System.Threading;
using Google.Apis.Auth.OAuth2;
using Google.Apis.Drive.v3;
using Google.Apis.Drive.v3.Data;
using Google.Apis.Requests;
using Google.Apis.Services;
using Google.Apis.Util.Store;

namespace ConsoleApp1
{
    class Program
    {
        private static UserCredential GetUserCredential(string clientSecretJson, string userName, string[] scopes)
        {
            try
            {
                if (string.IsNullOrEmpty(userName))
                    throw new ArgumentNullException("userName");
                if (string.IsNullOrEmpty(clientSecretJson))
                    throw new ArgumentNullException("clientSecretJson");
                if (!System.IO.File.Exists(clientSecretJson))
                    throw new Exception("clientSecretJson file does not exist.");

                // These are the scopes of permissions you need. It is best to request only what you need and not all of them               
                using (var stream = new FileStream(clientSecretJson, FileMode.Open, FileAccess.Read))
                {
                    string credPath = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal);
                    credPath = Path.Combine(credPath, ".credentials/",
                        System.Reflection.Assembly.GetExecutingAssembly().GetName().Name);

                    // Requesting Authentication or loading previously stored authentication for userName
                    var credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
                        GoogleClientSecrets.Load(stream).Secrets,
                        scopes,
                        userName,
                        CancellationToken.None,
                        new FileDataStore(credPath, true)).Result;

                    credential.GetAccessTokenForRequestAsync();
                    return credential;
                }
            }
            catch (Exception ex)
            {
                throw new Exception("Get user credentials failed.", ex);
            }
        }

        /// <summary>
        /// This method get a valid service
        /// </summary>
        /// <param name="credential">Authecated user credentail</param>
        /// <returns>DriveService used to make requests against the Drive API</returns>
        private static DriveService GetService(UserCredential credential)
        {
            try
            {
                if (credential == null)
                    throw new ArgumentNullException("credential");

                // Create Drive API service.
                return new DriveService(new BaseClientService.Initializer()
                {
                    HttpClientInitializer = credential,
                    ApplicationName = "Drive Oauth2 Authentication Sample"
                });
            }
            catch (Exception ex)
            {
                throw new Exception("Get Drive service failed.", ex);
            }
        }

        private const string pathToClientSecretJson = "";
        private const string userName = "Daimto";

        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");

            var cred = GetUserCredential(pathToClientSecretJson, userName,
                new[] {Google.Apis.Drive.v3.DriveService.Scope.Drive});
            var service = GetService(cred);
        }


        public class ListFilesOptionalParameters
        {
            /// <summary>
            /// Selector specifying which fields to include in a partial response.
            /// </summary>
            public string Fields { get; set; }

            /// <summary>
            /// An opaque string that represents a user for quota purposes. Must not exceed 40 characters.
            /// </summary>
            public string QuotaUser { get; set; }

            /// <summary>
            /// Lists or searches files.
            /// </summary>
            public string Corpora { get; set; }

            /// <summary>
            /// Lists or searches files.
            /// </summary>
            public string Corpus { get; set; }

            /// <summary>
            /// Lists or searches files.
            /// </summary>
            public string DriveId { get; set; }

            /// <summary>
            /// Lists or searches files.
            /// </summary>
            public bool IncludeItemsFromAllDrives { get; set; }

            /// <summary>
            /// Lists or searches files.
            /// </summary>
            public bool IncludeTeamDriveItems { get; set; }

            /// <summary>
            /// Lists or searches files.
            /// </summary>
            public string OrderBy { get; set; }

            /// <summary>
            /// Lists or searches files.
            /// </summary>
            public int PageSize { get; set; }

            /// <summary>
            /// Lists or searches files.
            /// </summary>
            public string PageToken { get; set; }

            /// <summary>
            /// Lists or searches files.
            /// </summary>
            public string Q { get; set; }

            /// <summary>
            /// Lists or searches files.
            /// </summary>
            public string Spaces { get; set; }

            /// <summary>
            /// Lists or searches files.
            /// </summary>
            public bool SupportsAllDrives { get; set; }

            /// <summary>
            /// Lists or searches files.
            /// </summary>
            public bool SupportsTeamDrives { get; set; }

            /// <summary>
            /// Lists or searches files.
            /// </summary>
            public string TeamDriveId { get; set; }
        }


        /// <summary>
        /// Lists or searches files.
        /// </summary>
        /// <param name="service"></param>
        /// <param name="options"></param>        
        /// <returns></returns>
        public static FileList ListFiles(DriveService service, ListFilesOptionalParameters options)
        {
            // A page streamer is a helper to provide both synchronous and asynchronous page streaming
            // of a listable or queryable resource.
            var pageStreamer =
                new PageStreamer<Google.Apis.Drive.v3.Data.File, FilesResource.ListRequest, FileList, string>(
                    (request, token) => request.PageToken = token,
                    response => response.NextPageToken, response => response.Files);

            try
            {
                var results = new FileList();
                var request = service.Files.List();

                // Applying optional parameters to the request.                
                request = (FilesResource.ListRequest) SampleHelpers.ApplyOptionalParms(request, options);


                // iterate through the results
                foreach (var result in pageStreamer.Fetch(request))
                {
                    results.Files.Add(result);
                }

                return results;
            }
            catch (Exception ex)
            {
                throw new Exception($"Request Files.List failed with message {ex.Message}", ex);
            }
        }
    }

    public static class SampleHelpers
    {
        /// <summary>
        /// Using reflection to apply optional parameters to the request.  
        /// 
        /// If the optonal parameters are null then we will just return the request as is.
        /// </summary>
        /// <param name="request">The request. </param>
        /// <param name="optional">The optional parameters. </param>
        /// <returns></returns>
        public static object ApplyOptionalParms(object request, object optional)
        {
            if (optional == null)
                return request;

            System.Reflection.PropertyInfo[] optionalProperties = (optional.GetType()).GetProperties();

            foreach (System.Reflection.PropertyInfo property in optionalProperties)
            {
                // Copy value from optional parms to the request.  They should have the same names and datatypes.
                System.Reflection.PropertyInfo piShared = (request.GetType()).GetProperty(property.Name);
                if (property.GetValue(optional, null) != null
                ) // TODO Test that we do not add values for items that are null
                    piShared.SetValue(request, property.GetValue(optional, null), null);
            }

            return request;
        }
    }
}