Exception.Source Property

 

Gets or sets the name of the application or the object that causes the error.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

Public Overridable Property Source As String

Property Value

Type: System.String

The name of the application or the object that causes the error.

Exception Condition
ArgumentException

The object must be a runtime System.Reflection object

If the Source property is not set explicitly, the runtime automatically sets it to the name of the assembly in which the exception originated.

The following example throws an Exception that sets the Source property in its constructor and then catches the exception and displays Source.

' Example for the Exception.HelpLink, Exception.Source,
' Exception.StackTrace, and Exception.TargetSite properties.
Imports System
Imports Microsoft.VisualBasic

Namespace NDP_UE_VB

    ' Derive an exception; the constructor sets the HelpLink and 
    ' Source properties.
    Class LogTableOverflowException
        Inherits Exception

        Private Const overflowMessage As String = _
            "The log table has overflowed."

        Public Sub New( auxMessage As String, inner As Exception )
            MyBase.New( String.Format( "{0} - {1}", _
                overflowMessage, auxMessage ), inner )

            Me.HelpLink = "http://msdn.microsoft.com"
            Me.Source = "Exception_Class_Samples"

        End Sub ' New
    End Class ' LogTableOverflowException

    Class LogTable

        Public Sub New(numElements As Integer)
            logArea = New String(numElements) {}
            elemInUse = 0
        End Sub ' New

        Protected logArea() As String
        Protected elemInUse As Integer

        ' The AddRecord method throws a derived exception if 
        ' the array bounds exception is caught.
        Public Function AddRecord( newRecord As String ) As Integer

            Try
                Dim curElement as Integer = elemInUse
                logArea( elemInUse ) = newRecord
                elemInUse += 1
                Return curElement

            Catch ex As Exception
                Throw New LogTableOverflowException( _
                    String.Format( "Record ""{0}"" was not logged.", _
                        newRecord ), ex )
            End Try
        End Function ' AddRecord
    End Class ' LogTable

    Module OverflowDemo

        ' Create a log table and force an overflow.
        Sub Main( )
            Dim log As New LogTable( 4 )

            Console.WriteLine( "This example of " & vbCrLf & _
                "   Exception.Message, " & vbCrLf & _
                "   Exception.HelpLink, " & vbCrLf & _
                "   Exception.Source, " & vbCrLf & _
                "   Exception.StackTrace, and " & vbCrLf & _
                "   Exception.TargetSite " & vbCrLf & _
                "generates the following output." )

            Try
                Dim count As Integer = 0

                Do
                    log.AddRecord( _
                        String.Format( "Log record number {0}", count ) )
                    count += 1
                Loop

            Catch ex As Exception
                Console.WriteLine( vbCrLf & _
                    "Message ---" & vbCrLf & ex.Message )
                Console.WriteLine( vbCrLf & _
                    "HelpLink ---" & vbCrLf & ex.HelpLink )
                Console.WriteLine( vbCrLf & _
                    "Source ---" & vbCrLf & ex.Source )
                Console.WriteLine( vbCrLf & _
                    "StackTrace ---" & vbCrLf & ex.StackTrace )
                Console.WriteLine( vbCrLf & "TargetSite ---" & _
                    vbCrLf & ex.TargetSite.ToString( ) )
            End Try
        End Sub ' Main

    End Module ' OverflowDemo
End Namespace ' NDP_UE_VB

' This example of
'    Exception.Message,
'    Exception.HelpLink,
'    Exception.Source,
'    Exception.StackTrace, and
'    Exception.TargetSite
' generates the following output.
' 
' Message ---
' The log table has overflowed. - Record "Log record number 5" was not logged.
' 
' HelpLink ---
' http://msdn.microsoft.com
' 
' Source ---
' Exception_Class_Samples
' 
' StackTrace ---
'    at NDP_UE_VB.LogTable.AddRecord(String newRecord)
'    at NDP_UE_VB.OverflowDemo.Main()
' 
' TargetSite ---
' Int32 AddRecord(System.String)

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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