我的连接字符串在其自己生成的连接字符串上出错。 我该如何解决？

Question

first time working with DB/SQL in Visual Studios 2017 So i created my own Database in with a table inside of it Now i want my code to connect to the DB and i used the generated connectionString but now i am getting errors like :System.Data.SqlClient.SqlException

That something on my connection OPEN is going wrong

namespace WindowsFormsApp2
{
    class DBConnect
    {
        public void connectDB()
        { 
            SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB; AttachDbFilename = C:\Users\xflak\OneDrive\Documenten\GitHub\ItemDatabase - UI\WindowsFormsApp2\Database1.mdf; Integrated Security = True");
            try
            {
                con.Open();
                Console.WriteLine("Connection Open!");
            }catch(Exception ex)
            {
                Console.WriteLine(ex.StackTrace);
            }
        }
    }
}

OLD Stacktrace

Exception thrown: 'System.Data.SqlClient.SqlException' in System.Data.dll
   bij System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, DbConnectionPool pool, String accessToken, Boolean applyTransientFaultHandling)
   bij System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
   bij System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
   bij System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   bij System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   bij System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   bij System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   bij System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
   bij System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   bij System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   bij System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
   bij System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
   bij System.Data.SqlClient.SqlConnection.Open()
   bij WindowsFormsApp2.DBConnect.connectDB() in C:\Users\xflak\OneDrive\Documenten\GitHub\ItemDatabase-UI\WindowsFormsApp2\DBConnect.cs:regel 17

New Stacktrace with SqlException en ex.ToString();

Exception thrown: 'System.Data.SqlClient.SqlException' in System.Data.dll
System.Data.SqlClient.SqlException (0x80131904): An attempt to attach an auto-named database for file C:\Users\xflak\OneDrive\Documenten\GitHub\ItemDatabase - UI\WindowsFormsApp2\Database1.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
   bij System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, DbConnectionPool pool, String accessToken, Boolean applyTransientFaultHandling)
   bij System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
   bij System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
   bij System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   bij System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   bij System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   bij System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   bij System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
   bij System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   bij System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   bij System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
   bij System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
   bij System.Data.SqlClient.SqlConnection.Open()
   bij WindowsFormsApp2.DBConnect.connectDB() in C:\Users\xflak\OneDrive\Documenten\GitHub\ItemDatabase-UI\WindowsFormsApp2\DBConnect.cs:regel 17
ClientConnectionId:200efe66-c5b0-4085-acb2-67a1c554ed67
Error Number:15350,State:1,Class:14

The relevant part is:

SqlException (0x80131904): An attempt to attach an auto-named database for file C:\\Users\\xflak\\OneDrive\\Documenten\\GitHub\\ItemDatabase - UI\\WindowsFormsApp2\\Database1.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.

Answer 1

尝试不使用AttachDbFilename并在初始目录中放入数据库名称。

SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB; Initial Catalog=Your database name ; Integrated Security = True")

Answer 2

I guess, you need to have the .mdf file in the accessible drive like D:/ or E:/ and try to have it in a folder without spaces.

I see you have a path having multiple spaces in it . ('ItemDatabase - UI' )