EventLogEntry.Source Property

public:
 property System::String ^ Source { System::String ^ get(); };

public string Source { get; }

member this.Source : string

Public ReadOnly Property Source As String

The name registered with the event log as the source of this event.

The following code example demonstrates the use of the Source property. In this example, a switch statement uses console input to search for event log entries for the specified EntryType. If a match is found, the Source property information is displayed at the console.

#using <System.dll>

using namespace System;
using namespace System::Diagnostics;

int main()
{
   String^ myEventType = nullptr;
   
   // Associate the instance of 'EventLog' with local System Log.
   EventLog^ myEventLog = gcnew EventLog( "System","." );
   Console::WriteLine( "1:Error" );
   Console::WriteLine( "2:Information" );
   Console::WriteLine( "3:Warning" );
   Console::WriteLine( "Select the Event Type" );
   int myOption = Convert::ToInt32( Console::ReadLine() );
   switch ( myOption )
   {
      case 1:
         myEventType = "Error";
         break;

      case 2:
         myEventType = "Information";
         break;

      case 3:
         myEventType = "Warning";
         break;

      default:
         break;
   }
   EventLogEntryCollection^ myLogEntryCollection = myEventLog->Entries;
   int myCount = myLogEntryCollection->Count;
   
   // Iterate through all 'EventLogEntry' instances in 'EventLog'.
   for ( int i = myCount - 1; i > -1; i-- )
   {
      EventLogEntry^ myLogEntry = myLogEntryCollection[ i ];
      
      // Select the entry having desired EventType.
      if ( myLogEntry->EntryType.Equals( myEventType ) )
      {
         // Display Source of the event.
         Console::WriteLine( "{0} was the source of last event of type {1}", myLogEntry->Source, myLogEntry->EntryType );
         return 0;
      }
   }
}

using System;
using System.Diagnostics;
   class MyEventlogClass
   {
      public static void Main()
      {
         String myEventType=null;
         // Associate the instance of 'EventLog' with local System Log.
         EventLog myEventLog = new EventLog("System", ".");
         Console.WriteLine("1:Error");
         Console.WriteLine("2:Information");
         Console.WriteLine("3:Warning");
         Console.WriteLine("Select the Event Type");
         int myOption=Convert.ToInt32(Console.ReadLine());
         switch(myOption)
         {
            case 1:  myEventType="Error";
                     break;
            case 2:  myEventType="Information";
                     break;
            case 3:  myEventType="Warning";
                     break;
            default: break;
         }

            EventLogEntryCollection myLogEntryCollection=myEventLog.Entries;
            int myCount =myLogEntryCollection.Count;
            // Iterate through all 'EventLogEntry' instances in 'EventLog'.
            for(int i=myCount-1;i>-1;i--)
            {
               EventLogEntry myLogEntry = myLogEntryCollection[i];
               // Select the entry having desired EventType.
               if(myLogEntry.EntryType.ToString().Equals(myEventType))
               {
                  // Display Source of the event.
                  Console.WriteLine(myLogEntry.Source
                     +" was the source of last event of type "
                     +myLogEntry.EntryType);
                  return;
               }
            }
         }
   }

Imports System.Diagnostics

Class MyEventlogClass
   Public Shared Sub Main()
      Dim myEventType As String = Nothing
      ' Associate the instance of 'EventLog' with local System Log.
      Dim myEventLog As New EventLog("System", ".")
      Console.WriteLine("1:Error")
      Console.WriteLine("2:Information")
      Console.WriteLine("3:Warning")
      Console.WriteLine("Select the Event Type")
      Dim myOption As Integer = Convert.ToInt32(Console.ReadLine())
      Select Case myOption
         Case 1
            myEventType = "Error"
         Case 2
            myEventType = "Information"
         Case 3
            myEventType = "Warning"
         Case Else
      End Select

      Dim myLogEntryCollection As EventLogEntryCollection = myEventLog.Entries
      Dim myCount As Integer = myLogEntryCollection.Count
      ' Iterate through all 'EventLogEntry' instances in 'EventLog'.
      Dim i As Integer
      For i = myCount - 1 To 0 Step -1
         Dim myLogEntry As EventLogEntry = myLogEntryCollection(i)
         ' Select the entry having desired EventType.
         If myLogEntry.EntryType.ToString().Equals(myEventType) Then
            ' Display Source of the event.
            Console.WriteLine(myLogEntry.Source + " was the source of last "& _
                             "event of type " & myLogEntry.EntryType.ToString())
            Return
         End If
      Next 
   End Sub
End Class

The event source indicates what logged the event. It is often the name of the application or the name of a subcomponent of the application if the application is large. Applications and services usually write to (and therefore are sources for) the Application log or a custom log. Device drivers usually write to the System log.

• Source