System.Data.SqlClient.SqlException (0x80131904): 连接超时时间已到。在尝试使用预登录握手确认时超过了此超时时间。这可能是因为预登录握手失败或服务器未能及时响应。 尝试连接到此服务器时花费的持续时间是 - [Pre-Login] initialization=2;handshake=15002; ---> System.ComponentModel.Win32Exception (0x80004005): 等待的操作过时。 在 System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection) 在 System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection) 在 System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection) 在 System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions) 在 System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry) 在 System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry) 在 System.Data.SqlClient.SqlConnection.Open() 在 DBBase.clsSQL.DataTable(SqlCommand cmd) 在 dataCenter.clsTree.getTreeByID(Int32 trID) 在 Magic.One.NoPageJump404() ClientConnectionId:611616e4-c6f4-4e00-acad-f0f5d1655676 Error Number:-2,State:0,Class:11