Exception.GetBaseException Método
Definición
Importante
Parte de la información hace referencia a la versión preliminar del producto, que puede haberse modificado sustancialmente antes de lanzar la versión definitiva. Microsoft no otorga ninguna garantía, explícita o implícita, con respecto a la información proporcionada aquí.
Cuando se invalida en una clase derivada, devuelve la clase Exception que representa la causa principal de una o más excepciones posteriores.
public:
virtual Exception ^ GetBaseException();public virtual Exception GetBaseException ();abstract member GetBaseException : unit -> Exception
override this.GetBaseException : unit -> ExceptionPublic Overridable Function GetBaseException () As ExceptionDevoluciones
Primera excepción que se produce en una cadena de excepciones. Si la propiedad InnerException de la excepción actual es una referencia nula (Nothing en Visual Basic), esta propiedad devuelve la excepción actual.
Implementaciones
Ejemplos
En el ejemplo de código siguiente se definen dos clases derivadas Exception . Fuerza una excepción y, a continuación, la inicia de nuevo con cada una de las clases derivadas. El código muestra el uso del GetBaseException método para recuperar la excepción original.
// Example for the Exception::GetBaseException method.
using namespace System;
namespace NDP_UE_CPP
{
// Define two derived exceptions to demonstrate nested exceptions.
ref class SecondLevelException: public Exception
{
public:
SecondLevelException( String^ message, Exception^ inner )
: Exception( message, inner )
{}
};
ref class ThirdLevelException: public Exception
{
public:
ThirdLevelException( String^ message, Exception^ inner )
: Exception( message, inner )
{}
};
// DivideBy0 forces a division by 0 and throws a second exception.
void DivideBy0()
{
try
{
int zero = 0;
int ecks = 1 / zero;
}
catch ( Exception^ ex )
{
throw gcnew SecondLevelException( "Forced a division by 0 and threw "
"a second exception.",ex );
}
}
// This function catches the exception from the called function
// DivideBy0( ) and throws another in response.
void Rethrow()
{
try
{
DivideBy0();
}
catch ( Exception^ ex )
{
throw gcnew ThirdLevelException( "Caught the second exception and "
"threw a third in response.",ex );
}
}
}
int main()
{
Console::WriteLine( "This example of Exception.GetBaseException "
"generates the following output." );
Console::WriteLine( "\nThe program forces a division by 0, "
"then throws the exception \ntwice more, "
"using a different derived exception each time.\n" );
try
{
// This function calls another that forces a division by 0.
NDP_UE_CPP::Rethrow();
}
catch ( Exception^ e )
{
Exception^ current;
Console::WriteLine( "Unwind the nested exceptions using "
"the InnerException property:\n" );
// This code unwinds the nested exceptions using the
// InnerException property.
current = e;
while ( current != (Object^)0 )
{
Console::WriteLine( current->ToString() );
Console::WriteLine();
current = current->InnerException;
}
// Display the innermost exception.
Console::WriteLine( "Display the base exception using the \n"
"GetBaseException method:\n" );
Console::WriteLine( e->GetBaseException()->ToString() );
}
}
/*
This example of Exception.GetBaseException generates the following output.
The program forces a division by 0, then throws the exception
twice more, using a different derived exception each time.
Unwind the nested exceptions using the InnerException property:
NDP_UE_CPP.ThirdLevelException: Caught the second exception and threw a third i
n response. ---> NDP_UE_CPP.SecondLevelException: Forced a division by 0 and th
rew a second exception. ---> System.DivideByZeroException: Attempted to divide
by zero.
at NDP_UE_CPP.DivideBy0()
--- End of inner exception stack trace ---
at NDP_UE_CPP.DivideBy0()
at NDP_UE_CPP.Rethrow()
--- End of inner exception stack trace ---
at NDP_UE_CPP.Rethrow()
at main()
NDP_UE_CPP.SecondLevelException: Forced a division by 0 and threw a second exce
ption. ---> System.DivideByZeroException: Attempted to divide by zero.
at NDP_UE_CPP.DivideBy0()
--- End of inner exception stack trace ---
at NDP_UE_CPP.DivideBy0()
at NDP_UE_CPP.Rethrow()
System.DivideByZeroException: Attempted to divide by zero.
at NDP_UE_CPP.DivideBy0()
Display the base exception using the
GetBaseException method:
System.DivideByZeroException: Attempted to divide by zero.
at NDP_UE_CPP.DivideBy0()
*/
// Example for the Exception.GetBaseException method.
using System;
namespace NDP_UE_CS
{
// Define two derived exceptions to demonstrate nested exceptions.
class SecondLevelException : Exception
{
public SecondLevelException( string message, Exception inner )
: base( message, inner )
{ }
}
class ThirdLevelException : Exception
{
public ThirdLevelException( string message, Exception inner )
: base( message, inner )
{ }
}
class NestedExceptions
{
public static void Main()
{
Console.WriteLine(
"This example of Exception.GetBaseException " +
"generates the following output." );
Console.WriteLine(
"\nThe program forces a division by 0, then " +
"throws the exception \ntwice more, " +
"using a different derived exception each time.\n" );
try
{
// This function calls another that forces a
// division by 0.
Rethrow( );
}
catch( Exception ex )
{
Exception current;
Console.WriteLine(
"Unwind the nested exceptions " +
"using the InnerException property:\n" );
// This code unwinds the nested exceptions using the
// InnerException property.
current = ex;
while( current != null )
{
Console.WriteLine( current.ToString( ) );
Console.WriteLine( );
current = current.InnerException;
}
// Display the innermost exception.
Console.WriteLine(
"Display the base exception " +
"using the GetBaseException method:\n" );
Console.WriteLine(
ex.GetBaseException( ).ToString( ) );
}
}
// This function catches the exception from the called
// function DivideBy0( ) and throws another in response.
static void Rethrow()
{
try
{
DivideBy0( );
}
catch( Exception ex )
{
throw new ThirdLevelException(
"Caught the second exception and " +
"threw a third in response.", ex );
}
}
// This function forces a division by 0 and throws a second
// exception.
static void DivideBy0( )
{
try
{
int zero = 0;
int ecks = 1 / zero;
}
catch( Exception ex )
{
throw new SecondLevelException(
"Forced a division by 0 and threw " +
"a second exception.", ex );
}
}
}
}
/*
This example of Exception.GetBaseException generates the following output.
The program forces a division by 0, then throws the exception
twice more, using a different derived exception each time.
Unwind the nested exceptions using the InnerException property:
NDP_UE_CS.ThirdLevelException: Caught the second exception and threw a third in
response. ---> NDP_UE_CS.SecondLevelException: Forced a division by 0 and thre
w a second exception. ---> System.DivideByZeroException: Attempted to divide by
zero.
at NDP_UE_CS.NestedExceptions.DivideBy0()
--- End of inner exception stack trace ---
at NDP_UE_CS.NestedExceptions.DivideBy0()
at NDP_UE_CS.NestedExceptions.Rethrow()
--- End of inner exception stack trace ---
at NDP_UE_CS.NestedExceptions.Rethrow()
at NDP_UE_CS.NestedExceptions.Main()
NDP_UE_CS.SecondLevelException: Forced a division by 0 and threw a second excep
tion. ---> System.DivideByZeroException: Attempted to divide by zero.
at NDP_UE_CS.NestedExceptions.DivideBy0()
--- End of inner exception stack trace ---
at NDP_UE_CS.NestedExceptions.DivideBy0()
at NDP_UE_CS.NestedExceptions.Rethrow()
System.DivideByZeroException: Attempted to divide by zero.
at NDP_UE_CS.NestedExceptions.DivideBy0()
Display the base exception using the GetBaseException method:
System.DivideByZeroException: Attempted to divide by zero.
at NDP_UE_CS.NestedExceptions.DivideBy0()
*/
// Example for the Exception.GetBaseException method.
open System
// Define two derived exceptions to demonstrate nested exceptions.
type SecondLevelException(message, inner: Exception) =
inherit Exception(message, inner)
type ThirdLevelException(message, inner: Exception) =
inherit Exception(message, inner)
printfn
"""This example of Exception.GetBaseException generates the following output.
The program forces a division by 0, then throws the exception
twice more, using a different derived exception each time.
"""
// This function forces a division by 0 and throws a second exception.
let divideBy0 () =
try
let zero = 0
let ecks = 1 / zero
()
with ex ->
raise (SecondLevelException("Forced a division by 0 and threw a second exception.", ex) )
// This function catches the exception from the called
// function divideBy0() and throws another in response.
let rethrow () =
try
divideBy0 ()
with ex ->
raise (ThirdLevelException("Caught the second exception and threw a third in response.", ex) )
try
// This function calls another that forces a
// division by 0.
rethrow ()
with ex ->
printfn "Unwind the nested exceptions using the InnerException property:\n"
// This code unwinds the nested exceptions using the
// InnerException property.
let mutable current = ex
while current <> null do
printfn $"{current}\n"
current <- current.InnerException
// Display the innermost exception.
printfn "Display the base exception using the GetBaseException method:\n"
printfn $"{ex.GetBaseException()}"
// This example of Exception.GetBaseException generates the following output.
//
// The program forces a division by 0, then throws the exception
// twice more, using a different derived exception each time.
//
// Unwind the nested exceptions using the InnerException property:
//
// NDP_UE_FS+ThirdLevelException: Caught the second exception and threw a third in
// response. ---> NDP_UE_FS.SecondLevelException: Forced a division by 0 and thre
// w a second exception. ---> System.DivideByZeroException: Attempted to divide by
// zero.
// at NDP_UE_FS.divideBy0()
// --- End of inner exception stack trace ---
// at NDP_UE_FS.divideBy0()
// at NDP_UE_FS.rethrow()
// --- End of inner exception stack trace ---
// at NDP_UE_FS.rethrow()
// at<StartupCode$fs>.$NDP_UE_FS.main@()
//
// NDP_UE_FS.SecondLevelException: Forced a division by 0 and threw a second excep
// tion. ---> System.DivideByZeroException: Attempted to divide by zero.
// at NDP_UE_FS.divideBy0()
// --- End of inner exception stack trace ---
// at NDP_UE_FS.divideBy0()
// at NDP_UE_FS.rethrow()
//
// System.DivideByZeroException: Attempted to divide by zero.
// at NDP_UE_FS.divideBy0()
//
// Display the base exception using the GetBaseException method:
//
// System.DivideByZeroException: Attempted to divide by zero.
// at NDP_UE_FS.divideBy0()
' Example for the Exception.GetBaseException method.
Namespace NDP_UE_VB
' Define two derived exceptions to demonstrate nested exceptions.
Class SecondLevelException
Inherits Exception
Public Sub New( message As String, inner As Exception )
MyBase.New( message, inner )
End Sub
End Class
Class ThirdLevelException
Inherits Exception
Public Sub New( message As String, inner As Exception )
MyBase.New( message, inner )
End Sub
End Class
Class NestedExceptions
Public Shared Sub Main( )
Console.WriteLine( _
"This example of Exception.GetBaseException " & _
"generates the following output." )
Console.WriteLine( vbCrLf & _
"The program forces a division by 0, then throws " & _
"the exception " & vbCrLf & "twice more, using " & _
"a different derived exception each time:" & vbCrLf )
Try
' This sub calls another that forces a division by 0.
Rethrow()
Catch ex As Exception
Dim current As Exception
Console.WriteLine( _
"Unwind the nested exceptions using the " & _
"InnerException property:" & vbCrLf )
' This code unwinds the nested exceptions using the
' InnerException property.
current = ex
While Not ( current Is Nothing )
Console.WriteLine( current.ToString( ) )
Console.WriteLine( )
current = current.InnerException
End While
' Display the innermost exception.
Console.WriteLine( _
"Display the base exception using the " & _
"GetBaseException method:" & vbCrLf )
Console.WriteLine( _
ex.GetBaseException( ).ToString( ) )
End Try
End Sub
' This sub catches the exception from the called sub
' DivideBy0( ) and throws another in response.
Shared Sub Rethrow( )
Try
DivideBy0( )
Catch ex As Exception
Throw New ThirdLevelException( _
"Caught the second exception and " & _
"threw a third in response.", ex )
End Try
End Sub
' This sub forces a division by 0 and throws a second
' exception.
Shared Sub DivideBy0( )
Try
Dim zero As Integer = 0
Dim ecks As Integer = 1 \ zero
Catch ex As Exception
Throw New SecondLevelException( _
"Forced a division by 0 and threw " & _
"a second exception.", ex )
End Try
End Sub
End Class
End Namespace ' NDP_UE_VB
' This example of Exception.GetBaseException generates the following output.
'
' The program forces a division by 0, then throws the exception
' twice more, using a different derived exception each time:
'
' Unwind the nested exceptions using the InnerException property:
'
' NDP_UE_VB.ThirdLevelException: Caught the second exception and threw a third
' in response. ---> NDP_UE_VB.SecondLevelException: Forced a division by 0 and
' threw a second exception. ---> System.DivideByZeroException: Attempted to div
' ide by zero.
' at NDP_UE_VB.NestedExceptions.DivideBy0()
' --- End of inner exception stack trace ---
' at NDP_UE_VB.NestedExceptions.DivideBy0()
' at NDP_UE_VB.NestedExceptions.Rethrow()
' --- End of inner exception stack trace ---
' at NDP_UE_VB.NestedExceptions.Rethrow()
' at NDP_UE_VB.NestedExceptions.Main()
'
' NDP_UE_VB.SecondLevelException: Forced a division by 0 and threw a second exc
' eption. ---> System.DivideByZeroException: Attempted to divide by zero.
' at NDP_UE_VB.NestedExceptions.DivideBy0()
' --- End of inner exception stack trace ---
' at NDP_UE_VB.NestedExceptions.DivideBy0()
' at NDP_UE_VB.NestedExceptions.Rethrow()
'
' System.DivideByZeroException: Attempted to divide by zero.
' at NDP_UE_VB.NestedExceptions.DivideBy0()
'
' Display the base exception using the GetBaseException method:
'
' System.DivideByZeroException: Attempted to divide by zero.
' at NDP_UE_VB.NestedExceptions.DivideBy0()
Comentarios
Una cadena de excepciones consta de un conjunto de excepciones de modo que cada excepción de la cadena se produjo como resultado directo de la excepción a la que se hace referencia en su InnerException propiedad. Para una cadena determinada, puede haber exactamente una excepción que sea la causa principal de todas las demás excepciones de la cadena. Esta excepción se denomina excepción base y su InnerException propiedad siempre contiene una referencia nula.
Para todas las excepciones de una cadena de excepciones, el GetBaseException método debe devolver el mismo objeto (la excepción base).
Use el GetBaseException método cuando desee encontrar la causa principal de una excepción, pero no necesita información sobre las excepciones que pueden haberse producido entre la excepción actual y la primera excepción.
Notas a los desarrolladores de herederos
El GetBaseException método se invalida en clases que requieren control sobre el contenido o el formato de la excepción.