Closes the System.Data.SqlClient.SqlDataReader object.
You must explicitly call the SqlDataReader.Close method when you are through using the System.Data.SqlClient.SqlDataReader to use the associated System.Data.SqlClient.SqlConnection for any other purpose.
The Close method fills in the values for output parameters, return values and RecordsAffected, increasing the time that it takes to close a SqlDataReader that was used to process a large or complex query. When the return values and the number of records affected by a query are not significant, the time that it takes to close the SqlDataReader can be reduced by calling the SqlCommand.Cancel method of the associated System.Data.SqlClient.SqlCommand object before calling the Close method.
Do not call Close or Dispose on a Connection, a DataReader, or any other managed object in the Finalize method of your class. In a finalizer, you should only release unmanaged resources that your class owns directly. If your class does not own any unmanaged resources, do not include a Finalize method in your class definition. For more information, see Garbage Collection.