EventLog.MinimumRetentionDays 屬性

定義

命名空間:

System.Diagnostics

組件:

System.Diagnostics.EventLog.dll

套件:

System.Diagnostics.EventLog v8.0.0

來源:

EventLog.cs

取得事件記錄檔項目的保留天數。

public:
 property int MinimumRetentionDays { int get(); };

[System.ComponentModel.Browsable(false)]
public int MinimumRetentionDays { get; }

[<System.ComponentModel.Browsable(false)>]
member this.MinimumRetentionDays : int

Public ReadOnly Property MinimumRetentionDays As Integer

屬性值

Int32

保留事件記錄檔項目的天數。 預設值為 7。

屬性

BrowsableAttribute

範例

下列範例會列舉本機計算機上定義的事件記錄檔，並顯示每個事件記錄檔的組態詳細數據。

void DisplayEventLogProperties()
{
   
   // Iterate through the current set of event log files,
   // displaying the property settings for each file.
   array<EventLog^>^eventLogs = EventLog::GetEventLogs();
   System::Collections::IEnumerator^ myEnum = eventLogs->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      EventLog^ e = safe_cast<EventLog^>(myEnum->Current);
      Int64 sizeKB = 0;
      Console::WriteLine();
      Console::WriteLine( "{0}:", e->LogDisplayName );
      Console::WriteLine( "  Log name = \t\t {0}", e->Log );
      Console::WriteLine( "  Number of event log entries = {0}", e->Entries->Count );
      
      // Determine if there is a file for this event log.
      RegistryKey ^ regEventLog = Registry::LocalMachine->OpenSubKey( String::Format( "System\\CurrentControlSet\\Services\\EventLog\\{0}", e->Log ) );
      if ( regEventLog )
      {
         Object^ temp = regEventLog->GetValue( "File" );
         if ( temp != nullptr )
         {
            Console::WriteLine( "  Log file path = \t {0}", temp );
            FileInfo^ file = gcnew FileInfo( temp->ToString() );
            
            // Get the current size of the event log file.
            if ( file->Exists )
            {
               sizeKB = file->Length / 1024;
               if ( (file->Length % 1024) != 0 )
               {
                  sizeKB++;
               }
               Console::WriteLine( "  Current size = \t {0} kilobytes", sizeKB );
            }
         }
         else
         {
            Console::WriteLine( "  Log file path = \t <not set>" );
         }
      }
      
      // Display the maximum size and overflow settings.
      sizeKB = e->MaximumKilobytes;
      Console::WriteLine( "  Maximum size = \t {0} kilobytes", sizeKB );
      Console::WriteLine( "  Overflow setting = \t {0}", e->OverflowAction );
      switch ( e->OverflowAction )
      {
         case OverflowAction::OverwriteOlder:
            Console::WriteLine( "\t Entries are retained a minimum of {0} days.", e->MinimumRetentionDays );
            break;

         case OverflowAction::DoNotOverwrite:
            Console::WriteLine( "\t Older entries are not overwritten." );
            break;

         case OverflowAction::OverwriteAsNeeded:
            Console::WriteLine( "\t If number of entries equals max size limit, a new event log entry overwrites the oldest entry." );
            break;

         default:
            break;
      }
   }
}

static void DisplayEventLogProperties()
{
    // Iterate through the current set of event log files,
    // displaying the property settings for each file.

    EventLog[] eventLogs = EventLog.GetEventLogs();
    foreach (EventLog e in eventLogs)
    {
        Int64 sizeKB = 0;

        Console.WriteLine();
        Console.WriteLine("{0}:", e.LogDisplayName);
        Console.WriteLine("  Log name = \t\t {0}", e.Log);

        Console.WriteLine("  Number of event log entries = {0}", e.Entries.Count.ToString());

        // Determine if there is an event log file for this event log.
        RegistryKey regEventLog = Registry.LocalMachine.OpenSubKey("System\\CurrentControlSet\\Services\\EventLog\\" + e.Log);
        if (regEventLog != null)
        {
            Object temp = regEventLog.GetValue("File");
            if (temp != null)
            {
                Console.WriteLine("  Log file path = \t {0}", temp.ToString());
                FileInfo file = new FileInfo(temp.ToString());

                // Get the current size of the event log file.
                if (file.Exists)
                {
                    sizeKB = file.Length / 1024;
                    if ((file.Length % 1024) != 0)
                    {
                        sizeKB++;
                    }
                    Console.WriteLine("  Current size = \t {0} kilobytes", sizeKB.ToString());
                }
            }
            else
            {
                Console.WriteLine("  Log file path = \t <not set>");
            }
        }

        // Display the maximum size and overflow settings.

        sizeKB = e.MaximumKilobytes;
        Console.WriteLine("  Maximum size = \t {0} kilobytes", sizeKB.ToString());
        Console.WriteLine("  Overflow setting = \t {0}", e.OverflowAction.ToString());

        switch (e.OverflowAction)
        {
            case OverflowAction.OverwriteOlder:
                Console.WriteLine("\t Entries are retained a minimum of {0} days.",
                    e.MinimumRetentionDays);
                break;
            case OverflowAction.DoNotOverwrite:
                Console.WriteLine("\t Older entries are not overwritten.");
                break;
            case OverflowAction.OverwriteAsNeeded:
                Console.WriteLine("\t If number of entries equals max size limit, a new event log entry overwrites the oldest entry.");
                break;
            default:
                break;
        }
    }
}

Shared Sub DisplayEventLogProperties()

   ' Iterate through the current set of event log files,
   ' displaying the property settings for each file.
   Dim eventLogs As EventLog() = EventLog.GetEventLogs()
   
   Dim e As EventLog
   For Each e In  eventLogs
      Dim sizeKB As Int64 = 0
      
      Console.WriteLine()
      Console.WriteLine("{0}:", e.LogDisplayName)
      Console.WriteLine("  Log name = " + ControlChars.Tab _
                          + ControlChars.Tab + " {0}", e.Log)

      Console.WriteLine("  Number of event log entries = {0}", e.Entries.Count.ToString())
      
      ' Determine if there is an event log file for this event log.
      Dim regEventLog As RegistryKey
      regEventLog = Registry.LocalMachine.OpenSubKey( _
             ("System\CurrentControlSet\Services\EventLog\" + e.Log))

      If Not (regEventLog Is Nothing) Then

         Dim temp As Object = regEventLog.GetValue("File")
         If Not (temp Is Nothing) Then

            Console.WriteLine("  Log file path = " + ControlChars.Tab _
                                  + " {0}", temp.ToString())
            Dim file As New FileInfo(temp.ToString())
            
            ' Get the current size of the event log file.
            If file.Exists Then
               sizeKB = file.Length / 1024
               If file.Length Mod 1024 <> 0 Then
                  sizeKB += 1
               End If
               Console.WriteLine("  Current size = " + ControlChars.Tab _
                          + " {0} kilobytes", sizeKB.ToString())
            End If
         Else
            Console.WriteLine("  Log file path = " + ControlChars.Tab _
                             + " <not set>")
         End If
      End If
      
      ' Display the maximum size and overflow settings.
      sizeKB = e.MaximumKilobytes
      Console.WriteLine("  Maximum size = " + ControlChars.Tab _
                         + " {0} kilobytes", sizeKB.ToString())
      Console.WriteLine("  Overflow setting = " + ControlChars.Tab _
                         + " {0}", e.OverflowAction.ToString())
      
      Select Case e.OverflowAction
         Case OverflowAction.OverwriteOlder
            Console.WriteLine(ControlChars.Tab + _
                 " Entries are retained a minimum of {0} days.", _
                 e.MinimumRetentionDays)
         Case OverflowAction.DoNotOverwrite
            Console.WriteLine(ControlChars.Tab + _
                 " Older entries are not overwritten.")
         Case OverflowAction.OverwriteAsNeeded
            Console.WriteLine(ControlChars.Tab + _
                 " If number of entries equals max size limit, a new event log entry overwrites the oldest entry.")
         Case Else
      End Select

   Next e

End Sub

備註

MinimumRetentionDays使用屬性來檢查事件記錄檔的目前設定。 使用 ModifyOverflowPolicy 變更事件記錄檔中每個項目必須保留的最小天數。

值 MinimumRetentionDays 取決於事件記錄檔的已設定溢位行為。 OverflowAction如果事件記錄檔的 屬性設定OverwriteAsNeeded為 ，則MinimumRetentionDays值為 0。 OverflowAction如果事件記錄檔的 屬性設定DoNotOverwrite為 ，則MinimumRetentionDays值為 -1。 OverflowAction如果事件記錄檔的 屬性設定OverwriteOlder為 ，則MinimumRetentionDays此值大於零，並代表事件記錄檔已滿時保留事件記錄檔專案的天數。

只有在事件記錄檔達到其大小限制時，才會發生溢位行為。 EventLog當 設定為 OverflowActionOverwriteOlder時，而且事件記錄檔達到其大小上限時，只有當新專案可以取代其年齡超過MinimumRetentionDays期間的專案時，才會寫入新的專案。 在定期封存事件記錄檔時，保留事件項目的時間下限是適當的。 否則，當事件記錄檔達到其限制時，您可能會遺失新專案。 若要避免遺失新的事件資訊，請根據特定事件記錄檔的封存排程設定事件的最低保留天數。

另請參閱

• MaximumKilobytes
• ModifyOverflowPolicy(OverflowAction, Int32)
• OverflowAction