FileRecordSequence.ReadLogRecords Method

Definition

Namespace:

System.IO.Log

Assembly:

System.IO.Log.dll

Returns an enumerable collection of records in the sequence. This method cannot be inherited.

public:
 virtual System::Collections::Generic::IEnumerable<System::IO::Log::LogRecord ^> ^ ReadLogRecords(System::IO::Log::SequenceNumber start, System::IO::Log::LogRecordEnumeratorType logRecordEnum);

public System.Collections.Generic.IEnumerable<System.IO.Log.LogRecord> ReadLogRecords (System.IO.Log.SequenceNumber start, System.IO.Log.LogRecordEnumeratorType logRecordEnum);

abstract member ReadLogRecords : System.IO.Log.SequenceNumber * System.IO.Log.LogRecordEnumeratorType -> seq<System.IO.Log.LogRecord>
override this.ReadLogRecords : System.IO.Log.SequenceNumber * System.IO.Log.LogRecordEnumeratorType -> seq<System.IO.Log.LogRecord>

Public Function ReadLogRecords (start As SequenceNumber, logRecordEnum As LogRecordEnumeratorType) As IEnumerable(Of LogRecord)

Parameters

start

SequenceNumber

The sequence number of the first record where the reading starts.

logRecordEnum

LogRecordEnumeratorType

A valid LogRecordEnumeratorType value that specifies the manner (that is, forward or backward) in which records should be read from a LogRecordSequence.

Returns

IEnumerable<LogRecord>

An enumerable collection of records in the sequence.

Implements

ReadLogRecords(SequenceNumber, LogRecordEnumeratorType)

Exceptions

ArgumentOutOfRangeException

One or more of the arguments are out of range.

NotSupportedException

The operation cannot be performed because the record sequence was opened with write-only access.

IOException

The record sequence is corrupted.

-or-

The record was written with an incompatible version of the record sequence.

InvalidOperationException

The enumeration has ended.

-or-

The enumeration has not been started. A call to MoveNext() must be made.

ObjectDisposedException

The method was called after the sequence has been disposed of.

OutOfMemoryException

There is not enough memory to continue the execution of the program.

Examples

The following example shows how you can use this method to read the records in a log sequence.

// Read the records added to the log.
    public void ReadRecords()
    {
        Encoding enc = Encoding.Unicode;

        Console.WriteLine();

        Console.WriteLine("Reading Log Records...");
        try
        {
            foreach (LogRecord record in this.sequence.ReadLogRecords(this.sequence.BaseSequenceNumber, LogRecordEnumeratorType.Next))
            {
                byte[] data = new byte[record.Data.Length];
                record.Data.Read(data, 0, (int)record.Data.Length);
                string mystr = enc.GetString(data);
                Console.WriteLine("    {0}", mystr);
            }
        }
        catch (Exception e)
        {
            Console.WriteLine("Exception {0} {1}", e.GetType(), e.Message);
        }

        Console.WriteLine();
    }

' Read the records added to the log. 
    Public Sub ReadRecords()
        Dim enc As Encoding = Encoding.Unicode

        Console.WriteLine()

        Console.WriteLine("Reading Log Records...")
        Try
            For Each record In Me.sequence.ReadLogRecords(Me.sequence.BaseSequenceNumber, LogRecordEnumeratorType.Next)
                Dim data(record.Data.Length - 1) As Byte
                record.Data.Read(data, 0, CInt(Fix(record.Data.Length)))
                Dim mystr As String = enc.GetString(data)
                Console.WriteLine("    {0}", mystr)
            Next record
        Catch e As Exception
            Console.WriteLine("Exception {0} {1}", e.GetType(), e.Message)
        End Try

        Console.WriteLine()
    End Sub

Remarks

This method returns an enumerable collection of records in the sequence. The order of the enumerated records depends on the value of the logRecordEnum parameter.