c# 进程无法访问该文件，因为它正被另一个进程使用。 即使在 sqlite 3 上关闭连接后

Question

所以我试图根据我的网络数量创建多个 SQLite 文件。 它已成功创建 SQLite 文件，但是当我尝试将其设为 zip 文件时，它给了我一个无法访问该文件的异常，因为它正被另一个进程使用。

 SqlConnection conn = new SqlConnection(cmn.connString);
            conn.Open();
            string query = "select networkid, network from custom_networkList";
            SqlCommand cmd = new SqlCommand(query, conn);
            SqlDataReader reader = cmd.ExecuteReader();
            while (reader.Read())
            {
                int networkid = Convert.ToInt32(reader["networkid"]);
                string network = reader["network"].ToString();

                File.Copy(Templatefile, newfile + network + ".sqlite", true);
                SQLiteConnection m_dbConnection = new SQLiteConnection(@"Data Source=" + newfile + network + ".sqlite;Version=3;");

                m_dbConnection.Open();
                SQLiteCommand command = new SQLiteCommand("begin", m_dbConnection);
                command.ExecuteNonQuery();

                insertZone(m_dbConnection);
                InsertJunctions(m_dbConnection, networkid);
                InsertHydrant(m_dbConnection, networkid);
                insertWaterTank(m_dbConnection, networkid);
                insertPump(m_dbConnection, networkid);
                InsertReservoir(m_dbConnection, networkid);
                insertValve(m_dbConnection, networkid);
                insertPipe(m_dbConnection, networkid);

                command = new SQLiteCommand("end", m_dbConnection);
                command.ExecuteNonQuery();
                m_dbConnection.Close();
                command.Dispose();
                m_dbConnection.Dispose();
            }
            conn.Close();


            GC.WaitForPendingFinalizers();
            GC.Collect();

            if (!Directory.Exists(newfilename))
            {
                // Try to create the directory.
                File.Delete(newfilename);
            }
            ZipFile.CreateFromDirectory(newfile, newfilename, CompressionLevel.Fastest, true);
            Directory.Delete(newfile,true);

            return newfilename2;

Answer 1

尝试一下，我认为如果使用

 using (SqlConnection conn = new SqlConnection(cmn.connString))
        {
            conn.Open();
            string query = "select networkid, network from custom_networkList";
            using (SqlCommand cmd = new SqlCommand(query, conn))
            using (SqlDataReader reader = cmd.ExecuteReader())
            {
                while (reader.Read())
                {
                    int networkid = Convert.ToInt32(reader["networkid"]);
                    string network = reader["network"].ToString();

                    File.Copy(Templatefile, newfile + network + ".sqlite", true);
                    using (SQLiteConnection m_dbConnection = new SQLiteConnection(@"Data Source=" + newfile + network + ".sqlite;Version=3;"))
                    {
                        m_dbConnection.Open();
                        using (SQLiteCommand command = new SQLiteCommand("begin", m_dbConnection))
                        {
                            command.ExecuteNonQuery();

                            insertZone(m_dbConnection);
                            InsertJunctions(m_dbConnection, networkid);
                            InsertHydrant(m_dbConnection, networkid);
                            insertWaterTank(m_dbConnection, networkid);
                            insertPump(m_dbConnection, networkid);
                            InsertReservoir(m_dbConnection, networkid);
                            insertValve(m_dbConnection, networkid);
                            insertPipe(m_dbConnection, networkid);

                            using (command = new SQLiteCommand("end", m_dbConnection))
                            {
                                command.ExecuteNonQuery();
                            }
                            // m_dbConnection.Close();
                            // command.Dispose();
                        }

                    }
                }

            }
        }

        GC.WaitForPendingFinalizers();
        GC.Collect();

        if (!Directory.Exists(newfilename))
        {
            // Try to create the directory.
            File.Delete(newfilename);
        }
        ZipFile.CreateFromDirectory(newfile, newfilename, CompressionLevel.Fastest, true);
        Directory.Delete(newfile, true);

        return newfilename2;

要处理任何文件，您必须执行以下操作

using (FileStream fs = File.Open(filePath, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite))
        {

            using (StreamReader sr = new StreamReader(fs, Encoding.Default))
            {




            }

            // or 
            using (StreamWriter sw = new StreamWriter(fs, Encoding.Default))
            {




            }


//  you can zip file or do what you want  here
        }

希望你能解决这个问题

Answer 2

在较新的 SQLite 客户端版本上，由于行为改变：连接池的引入，可能会发生错误“进程无法访问文件'...'，因为它正被另一个进程使用”。 我有效地使用了以下解决方法，通过将 Pooling=false 添加到连接字符串来禁用池。

来自： https://github.com/dotnet/efcore/issues/27139#issuecomment-1007588298

SQLite 提供程序现在汇集连接，显着提高连接速度但保持连接打开。 您可以通过将 Pooling=false 添加到连接字符串或在您希望它们关闭的位置调用 SqliteConnection.ClearAllPools() 来禁用池。

还记录在https://docs.microsoft.com/en-us/ef/core/what-is-new/ef-core-6.0/break-changes#sqlite-connections-are-pooled