error: System.InvalidOperationException: No se ha inicializado la propiedad ConnectionString.
en System.Data.SqlClient.SqlConnection.PermissionDemand()
en System.Data.SqlClient.SqlConnectionFactory.PermissionDemand(DbConnection outerConnection)
en System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
en System.Data.SqlClient.SqlConnection.Open()
en System.Data.Common.DbDataAdapter.QuietOpen(IDbConnection connection, ConnectionState& originalState)
en System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
en System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
en System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, String srcTable)
en pepecobo.users.calendario.CargarDatos()
PEPE COBO