Exception.Message Property


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Gets a message that describes the current exception.

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

Public Overridable ReadOnly Property Message As String

Property Value

Type: System.String

The error message that explains the reason for the exception, or an empty string ("").

Error messages target the developer who is handling the exception. The text of the Message property should completely describe the error and, when possible, should also explain how to correct the error. Top-level exception handlers may display the message to end-users, so you should ensure that it is grammatically correct and that each sentence of the message ends with a period. Do not use question marks or exclamation points. If your application uses localized exception messages, you should ensure that they are accurately translated.

System_CAPS_security Security Note

Do not disclose sensitive information in exception messages without checking for the appropriate permissions.

The value of the Message property is included in the information returned by ToString.The Message property is set only when creating an Exception. If no message was supplied to the constructor for the current instance, the system supplies a default message that is formatted using the current system culture.

Starting with the .NET Framework 4.5.1 and Windows 8.1, the fidelity of error messages from exceptions that are propagated from Windows Runtime types and members that are not part of the .NET Framework is improved. In particular, exception messages from Visual C++ component extensions (C++/CX) are now propagated back into .NET Framework Exception objects.

Notes to Implementers:

If you throw an exception from a property, and you need to refer in the text of Message to the property argument that you set or get, use "value" as the name of the property argument.

Notes to Inheritors:

The Message property is overridden in classes that require control over message content or format. Application code typically accesses this property when it needs to display information about an exception that has been caught.

The error message should be localized.

The following code example throws and then catches an ExceptionException and displays the exception's text message using the Message property.

' 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

                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." )

                Dim count As Integer = 0

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

            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
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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