如何使用C#以编程方式找到我的Google云端硬盘文件夹？

Question

类似的问题在这里.只是Google Drive代替Dropbox:

如何Google Drive使用C#以编程方式查找我的文件夹？

• 注册？
• 环境变量？
• 等等...

Answer 1

我个人认为,最好的方法是通过SQLite3访问同一个文件.

string dbFilePath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "Google\\Drive\\sync_config.db");
if (!File.Exists(dbFilePath))
    dbFilePath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "Google\\Drive\\user_default\\sync_config.db");

string csGdrive = @"Data Source="+ dbFilePath + ";Version=3;New=False;Compress=True;";                
SQLiteConnection con = new SQLiteConnection(csGdrive);
con.Open();
SQLiteCommand sqLitecmd = new SQLiteCommand(con);

//To retrieve the folder use the following command text
sqLitecmd.CommandText = "select * from data where entry_key='local_sync_root_path'";

SQLiteDataReader reader = sqLitecmd.ExecuteReader();
reader.Read();
//String retrieved is in the format "\\?\<path>" that's why I have used Substring function to extract the path alone.
Console.WriteLine("Google Drive Folder: " + reader["data_value"].ToString().Substring(4));
con.Dispose();

您可以从此处获取.Net的SQLite库.还要System.Data.SQLite在项目中添加引用并将其包含在内,以运行上面的代码.

要检索用户,请entry_key='user_email'从上面的代码中重新定位

Answer 2

我接受了 Sarath 的答案，对其进行了重新设计以使其更具弹性（围绕数据源路径的引号、基于读取器索引的 null 条件、额外的错误检查、“使用”以便适当处理对象、添加一堆注释，并加入一些 LINQ（因为，linq :-))。

这个特定的实现捕获并记录异常，然后在出现任何错误时返回 string.Empty...因为这就是我当前的应用程序需要它的方式。如果您的应用需要例外，请移除 try/catch。

/// <summary>
/// Retrieves the local Google Drive directory, if any.
/// </summary>
/// <returns>Directory, or string.Empty if it can't be found</returns>
public static string GetGoogleDriveDirectory()
{
    try
    {
        // Google Drive's sync database can be in a couple different locations. Go find it. 
        string appDataPath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
        string dbName = "sync_config.db";
        var pathsToTry = new[] { @"Google\Drive\" + dbName, @"Google\Drive\user_default\"+ dbName };

        string syncDbPath = (from p in pathsToTry
                            where File.Exists(Path.Combine(appDataPath, p))
                            select Path.Combine(appDataPath, p))
                            .FirstOrDefault();
        if (syncDbPath == null)
            throw new FileNotFoundException("Cannot find Google Drive sync database", dbName);

        // Build the connection and sql command
        string conString = string.Format(@"Data Source='{0}';Version=3;New=False;Compress=True;", syncDbPath);
        using (var con = new SQLiteConnection(conString))
        using (var cmd = new SQLiteCommand("select * from data where entry_key='local_sync_root_path'", con))
        {
            // Open the connection and execute the command
            con.Open();
            var reader = cmd.ExecuteReader();
            reader.Read();

            // Extract the data from the reader
            string path = reader["data_value"]?.ToString();
            if (string.IsNullOrWhiteSpace(path))
                throw new InvalidDataException("Cannot read 'local_sync_root_path' from Google Drive configuration db");

            // By default, the path will be prefixed with "\\?\" (unless another app has explicitly changed it).
            // \\?\ indicates to Win32 that the filename may be longer than MAX_PATH (see MSDN). 
            // Parts of .NET (e.g. the File class) don't handle this very well, so remove this prefix.
            if (path.StartsWith(@"\\?\"))
                path = path.Substring(@"\\?\".Length);

            return path;
        }
    }
    catch (Exception ex)
    {
        Trace.TraceError("Cannot determine Google Drive location. Error {0} - {1}", ex.Message, ex.StackTrace);
        return string.Empty;
    }
}