Exception.Message Eigenschaft
Definition
Wichtig
Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.
Ruft eine Meldung ab, mit der die aktuelle Ausnahme beschrieben wird.
public:
virtual property System::String ^ Message { System::String ^ get(); };
public virtual string Message { get; }
member this.Message : string
Public Overridable ReadOnly Property Message As String
Eigenschaftswert
Die Fehlermeldung, die den Grund für die Ausnahme erläutert, oder eine leere Zeichenfolge ("").
Implementiert
Beispiele
Im folgenden Codebeispiel wird eine Exception Ausnahme ausgelöst und dann abfangen und die Textnachricht der Ausnahme mithilfe der Message -Eigenschaft angezeigt.
// Example for the Exception::HelpLink, Exception::Source,
// Exception::StackTrace, and Exception::TargetSite properties.
using namespace System;
namespace NDP_UE_CPP
{
// Derive an exception; the constructor sets the HelpLink and
// Source properties.
public ref class LogTableOverflowException: public Exception
{
private:
static String^ overflowMessage = "The log table has overflowed.";
public:
LogTableOverflowException( String^ auxMessage, Exception^ inner )
: Exception( String::Format( "{0} - {1}", overflowMessage, auxMessage ), inner )
{
this->HelpLink = "https://learn.microsoft.com";
this->Source = "Exception_Class_Samples";
}
};
public ref class LogTable
{
public:
LogTable( int numElements )
{
logArea = gcnew array<String^>(numElements);
elemInUse = 0;
}
protected:
array<String^>^logArea;
int elemInUse;
public:
// The AddRecord method throws a derived exception if
// the array bounds exception is caught.
int AddRecord( String^ newRecord )
{
try
{
logArea[ elemInUse ] = newRecord;
return elemInUse++;
}
catch ( Exception^ ex )
{
throw gcnew LogTableOverflowException( String::Format( "Record \"{0}\" was not logged.", newRecord ),ex );
}
}
};
// Create a log table and force an overflow.
void ForceOverflow()
{
LogTable^ log = gcnew LogTable( 4 );
try
{
for ( int count = 1; ; count++ )
{
log->AddRecord( String::Format( "Log record number {0}", count ) );
}
}
catch ( Exception^ ex )
{
Console::WriteLine( "\nMessage ---\n{0}", ex->Message );
Console::WriteLine( "\nHelpLink ---\n{0}", ex->HelpLink );
Console::WriteLine( "\nSource ---\n{0}", ex->Source );
Console::WriteLine( "\nStackTrace ---\n{0}", ex->StackTrace );
Console::WriteLine( "\nTargetSite ---\n{0}", ex->TargetSite->ToString() );
}
}
}
int main()
{
Console::WriteLine( "This example of \n Exception::Message, \n"
" Exception::HelpLink, \n Exception::Source, \n"
" Exception::StackTrace, and \n Exception::"
"TargetSite \ngenerates the following output." );
NDP_UE_CPP::ForceOverflow();
}
/*
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 ---
https://learn.microsoft.com
Source ---
Exception_Class_Samples
StackTrace ---
at NDP_UE_CPP.LogTable.AddRecord(String newRecord)
at NDP_UE_CPP.ForceOverflow()
TargetSite ---
Int32 AddRecord(System.String)
*/
// Example for the Exception.HelpLink, Exception.Source,
// Exception.StackTrace, and Exception.TargetSite properties.
using System;
namespace NDP_UE_CS
{
// Derive an exception; the constructor sets the HelpLink and
// Source properties.
class LogTableOverflowException : Exception
{
const string overflowMessage = "The log table has overflowed.";
public LogTableOverflowException(
string auxMessage, Exception inner ) :
base( String.Format( "{0} - {1}",
overflowMessage, auxMessage ), inner )
{
this.HelpLink = "https://learn.microsoft.com";
this.Source = "Exception_Class_Samples";
}
}
class LogTable
{
public LogTable( int numElements )
{
logArea = new string[ numElements ];
elemInUse = 0;
}
protected string[ ] logArea;
protected int elemInUse;
// The AddRecord method throws a derived exception if
// the array bounds exception is caught.
public int AddRecord( string newRecord )
{
try
{
logArea[ elemInUse ] = newRecord;
return elemInUse++;
}
catch( Exception e )
{
throw new LogTableOverflowException(
String.Format( "Record \"{0}\" was not logged.",
newRecord ), e );
}
}
}
class OverflowDemo
{
// Create a log table and force an overflow.
public static void Main()
{
LogTable log = new LogTable( 4 );
Console.WriteLine(
"This example of \n Exception.Message, \n" +
" Exception.HelpLink, \n Exception.Source, \n" +
" Exception.StackTrace, and \n Exception." +
"TargetSite \ngenerates the following output." );
try
{
for( int count = 1; ; count++ )
{
log.AddRecord(
String.Format(
"Log record number {0}", count ) );
}
}
catch( Exception ex )
{
Console.WriteLine( "\nMessage ---\n{0}", ex.Message );
Console.WriteLine(
"\nHelpLink ---\n{0}", ex.HelpLink );
Console.WriteLine( "\nSource ---\n{0}", ex.Source );
Console.WriteLine(
"\nStackTrace ---\n{0}", ex.StackTrace );
Console.WriteLine(
"\nTargetSite ---\n{0}", ex.TargetSite );
}
}
}
}
/*
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 ---
https://learn.microsoft.com
Source ---
Exception_Class_Samples
StackTrace ---
at NDP_UE_CS.LogTable.AddRecord(String newRecord)
at NDP_UE_CS.OverflowDemo.Main()
TargetSite ---
Int32 AddRecord(System.String)
*/
// Example for the Exception.HelpLink, Exception.Source,
// Exception.StackTrace, and Exception.TargetSite properties.
open System
let overflowMessage = "The log table has overflowed."
// Derive an exception; the constructor sets the HelpLink and
// Source properties.
type LogTableOverflowException(auxMessage, inner) as this =
inherit Exception($"%s{overflowMessage} - %s{auxMessage}", inner)
do
this.HelpLink <- "https://learn.microsoft.com"
this.Source <- "Exception_Class_Samples"
type LogTable(numElements) =
let logArea = Array.zeroCreate<string> numElements
let mutable elemInUse = 0
// The AddRecord method throws a derived exception if
// the array bounds exception is caught.
member this.AddRecord(newRecord) =
try
logArea[elemInUse] <- newRecord
elemInUse <- elemInUse + 1
elemInUse - 1
with e ->
raise (LogTableOverflowException($"Record \"{newRecord}\" was not logged.", e) )
// Create a log table and force an overflow.
let log = LogTable 4
printfn
"""This example of
Exception.Message,
Exception.HelpLink,
Exception.Source,
Exception.StackTrace, and
Exception.TargetSite
generates the following output."""
try
for count = 1 to 1000000 do
log.AddRecord $"Log record number {count}"
|> ignore
with ex ->
printfn $"\nMessage ---\n{ex.Message}"
printfn $"\nHelpLink ---\n{ex.HelpLink}"
printfn $"\nSource ---\n{ex.Source}"
printfn $"\nStackTrace ---\n{ex.StackTrace}"
printfn $"\nTargetSite ---\n{ex.TargetSite}"
// This example of
// Exception.Message,
// Exception.HelpLink,
// Exception.Source,
// Exception.StackTrace, and
// Exception.TargetSite
// generates the following output.
// Message ---
// The log table has overflowed. - Record "Log record number 5" was not logged.
// HelpLink ---
// https://learn.microsoft.com
// Source ---
// Exception_Class_Samples
// StackTrace ---
// at NDP_UE_FS.LogTable.AddRecord(String newRecord)
// at <StartupCode$fs>.$NDP_UE_FS.main@()
// TargetSite ---
// Int32 AddRecord(System.String)
' Example for the Exception.HelpLink, Exception.Source,
' Exception.StackTrace, and Exception.TargetSite properties.
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 = "https://learn.microsoft.com"
Me.Source = "Exception_Class_Samples"
End Sub
End Class
Class LogTable
Public Sub New(numElements As Integer)
logArea = New String(numElements) {}
elemInUse = 0
End Sub
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
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
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 ---
' https://learn.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)
Hinweise
Fehlermeldungen richten sich an den Entwickler, der die Ausnahme behandelt. Der Text der Message -Eigenschaft sollte den Fehler vollständig beschreiben und, wenn möglich, auch erklären, wie der Fehler korrigiert wird. Ausnahmehandler der obersten Ebene können die Nachricht für Endbenutzer anzeigen. Daher sollten Sie sicherstellen, dass sie grammatikalisch korrekt ist und jeder Satz der Nachricht mit einem Punkt endet. Verwenden Sie keine Fragezeichen oder Ausrufezeichen. Wenn Ihre Anwendung lokalisierte Ausnahmemeldungen verwendet, sollten Sie sicherstellen, dass sie korrekt übersetzt werden.
Wichtig
Geben Sie keine vertraulichen Informationen in Ausnahmemeldungen offen, ohne die entsprechenden Berechtigungen zu überprüfen.
Der Wert der Message -Eigenschaft ist in den von ToStringzurückgegebenen Informationen enthalten. Die Message -Eigenschaft wird nur beim Erstellen eines Exceptionfestgelegt. Wenn keine Nachricht für den Konstruktor für den aktuellen instance bereitgestellt wurde, stellt das System eine Standardnachricht bereit, die mit der aktuellen Systemkultur formatiert ist.
Hinweise für Vererber
Die Message -Eigenschaft wird in Klassen überschrieben, die die Kontrolle über den Nachrichteninhalt oder das Format erfordern. Der Anwendungscode greift in der Regel auf diese Eigenschaft zu, wenn Er Informationen zu einer ausnahme anzeigen muss, die abgefangen wurde.
Die Fehlermeldung sollte lokalisiert werden.