如何从 C# 中的 Google Drive API 获取所有文件夹中的所有文件

Question

我可以通过以下引用使用 API 从 Google Drive 获取文件：Display (View) list of files from Google Drive using Google Drive API in ASP.Net with C# and VB.Net 。

但我只得到 100 条记录。我有几千条记录。任何人都可以让我知道要更改什么以获得完整的记录显示。

请在下面找到代码：

namespace GoogleDrive
{
    public partial class gDrive : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            GoogleConnect.ClientId = "942196220502-k107l4mtn6n606d8m38pp2k6clfmbftd.apps.googleusercontent.com";
            GoogleConnect.ClientSecret = "oJxTZ2Bw9QfOlrc7KgxsEf9o";
            GoogleConnect.RedirectUri = Request.Url.AbsoluteUri.Split('?')[0];
            GoogleConnect.API = EnumAPI.Drive;
            if (!string.IsNullOrEmpty(Request.QueryString["code"]))
            {
                string code = Request.QueryString["code"];
                string json = GoogleConnect.Fetch("me", code);
                GoogleDriveFiles files = new JavaScriptSerializer().Deserialize<GoogleDriveFiles>(json);
                gv1.DataSource = files.Items.Where(i => i.Labels.Trashed == false);
                gv1.DataBind();
            }
            else if (Request.QueryString["error"] == "access_denied")
            {
                ClientScript.RegisterClientScriptBlock(this.GetType(), "alert", "alert('Access denied.')", true);
            }
            else
            {
                GoogleConnect.Authorize("https://www.googleapis.com/auth/drive.readonly");
            }
        }

        public class GoogleDriveFiles
        {
            public List<GoogleDriveFile> Items { get; set; }
        }

        public class GoogleDriveFile
        {
            public string Id { get; set; }
            public string Title { get; set; }
            public string OriginalFilename { get; set; }
            public string ThumbnailLink { get; set; }
            public string IconLink { get; set; }
            public string WebContentLink { get; set; }
            public DateTime CreatedDate { get; set; }
            public DateTime ModifiedDate { get; set; }
            public GoogleDriveFileLabel Labels { get; set; }
            public string alternateLink { get; set; }
            public Boolean editable { get; set; }
        }

        public class GoogleDriveFileLabel
        {
            public bool Starred { get; set; }
            public bool Hidden { get; set; }
            public bool Trashed { get; set; }
            public bool Restricted { get; set; }
            public bool Viewed { get; set; }
        }
    }
}

---

以下代码适用于获取前1000条记录。

namespace gDrive
{
    class Program
    {
        static string[] Scopes = { DriveService.Scope.DriveReadonly };
        static string ApplicationName = "Drive API .NET Quickstart";

    static void Main(string[] args)
    {
        UserCredential credential;
        gDriveTableAdapter gDrive = new gDriveTableAdapter();

        using (var stream =
            new FileStream("client_secret.json", FileMode.Open, FileAccess.Read))
        {
            string credPath = System.Environment.GetFolderPath(
                System.Environment.SpecialFolder.Personal);
            credPath = Path.Combine(credPath, ".credentials/drive-dotnet-quickstart.json");

            credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
                GoogleClientSecrets.Load(stream).Secrets,
                Scopes,
                "user",
                CancellationToken.None,
                new FileDataStore(credPath, true)).Result;
            //Console.WriteLine("Credential file saved to: " + credPath);
        }

        // Create Drive API service.
        var service = new DriveService(new BaseClientService.Initializer()
        {
            HttpClientInitializer = credential,
            ApplicationName = ApplicationName,
        });

        // Define parameters of request.
        FilesResource.ListRequest listRequest = service.Files.List();
        listRequest.PageSize = 1000;
        listRequest.Fields = "nextPageToken, files(webViewLink, name)";

        // List files.
        IList<Google.Apis.Drive.v3.Data.File> files = listRequest.Execute()
            .Files;
        Console.WriteLine("Processing...\n");
        if (files != null && files.Count > 0)
        {
            foreach (var file in files)
            {
                gDrive.InsertQuery(file.Name, file.WebViewLink);
            }
            Console.WriteLine(files.Count + " records fetched.");
        }
        else
        {
            Console.WriteLine("No files found.");
        }
        Console.Read();
    }
  }
}

Answer 1

您似乎正在使用 Google Drive api V2。如果您将 maxResults 参数设置为 1000，您将返回前 1000 行。如果有额外的行 page Token 作为响应的一部分返回。您将需要发送另一个请求并将 pageToken 添加到新请求中，这将为您返回下一次发送的数据。我不熟悉那个库，所以不能帮你修改代码。

注意：您所遵循的教程是 2014 年的，它没有使用最新版本的 Google Drive API which is V3。另外，您没有使用官方的Google .Net client library。

更新：

这是我为 Google Drive API 列出所有文件的方法。它显示了如何创建页面流媒体，并将返回所有文件的完整列表。注意：它将继续请求数据，直到您的谷歌驱动器上没有更多数据。我不负责吃掉你的配额:)

public class FilesListOptionalParms
    {
        /// The source of files to list.
        public string Corpus { get; set; }  
        /// A comma-separated list of sort keys. Valid keys are 'createdTime', 'folder', 'modifiedByMeTime', 'modifiedTime', 'name', 'quotaBytesUsed', 'recency', 'sharedWithMeTime', 'starred', and 'viewedByMeTime'. Each key sorts ascending by default, but may be reversed with the 'desc' modifier. Example usage: ?orderBy=folder,modifiedTime desc,name. Please note that there is a current limitation for users with approximately one million files in which the requested sort order is ignored.
        public string OrderBy { get; set; }  
        /// The maximum number of files to return per page.
        public int PageSize { get; set; }  
        /// The token for continuing a previous list request on the next page. This should be set to the value of 'nextPageToken' from the previous response.
        public string PageToken { get; set; }  
        /// A query for filtering the file results. See the "Search for Files" guide for supported syntax.
        public string Q { get; set; }  
        /// A comma-separated list of spaces to query within the corpus. Supported values are 'drive', 'appDataFolder' and 'photos'.
        public string Spaces { get; set; }  

    }

    /// <summary>
    /// Lists or searches files. 
    /// Documentation https://developers.google.com/drive/v3/reference/files/list
    /// Generation Note: This does not always build correctly.  Google needs to standardize things I need to figure out which ones are wrong.
    /// </summary>
    /// <param name="service">Authenticated Drive service. </param>
    /// <param name="optional">The optional parameters. </param>        
    /// <returns>FileListResponse</returns>
    public static Google.Apis.Drive.v3.Data.FileList ListAll(DriveService service, FilesListOptionalParms optional = null)
    {
        try
        {
            // Initial validation.
            if (service == null)
                throw new ArgumentNullException("service");

            // Building the initial request.
            var request = service.Files.List();

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

            var pageStreamer = new Google.Apis.Requests.PageStreamer<Google.Apis.Drive.v3.Data.File, FilesResource.ListRequest, Google.Apis.Drive.v3.Data.FileList, string>(
                                               (req, token) => request.PageToken = token,
                                               response => response.NextPageToken,
                                               response => response.Files);


            var allFiles = new Google.Apis.Drive.v3.Data.FileList();
            allFiles.Files = new List<Google.Apis.Drive.v3.Data.File>();

            foreach (var result in pageStreamer.Fetch(request))
            {                    
                allFiles.Files.Add(result);
            }

            return allFiles;

        }
        catch (Exception Ex)
        {
            throw new Exception("Request Files.List failed.", Ex);
        }
    }

从我的项目中提取的可选参数：Unofficial Drive sample 列出从我的 gist 中提取的所有文件：gist