ExceptionHandlingClause ExceptionHandlingClause ExceptionHandlingClause ExceptionHandlingClause Class

Definición

Representa una cláusula de un bloque de control de excepciones estructurado.Represents a clause in a structured exception-handling block.

public ref class ExceptionHandlingClause
[System.Runtime.InteropServices.ComVisible(true)]
public class ExceptionHandlingClause
type ExceptionHandlingClause = class
Public Class ExceptionHandlingClause
Herencia
ExceptionHandlingClauseExceptionHandlingClauseExceptionHandlingClauseExceptionHandlingClause
Atributos

Ejemplos

En el ejemplo de código siguiente se define un MethodBodyExamplemétodo de prueba denominado y se muestra su información de variable local y las cláusulas de control de excepciones.The following code example defines a test method named MethodBodyExample, and displays its local variable information and exception-handling clauses. El MethodBase.GetMethodBody método se utiliza para obtener un MethodBody objeto para el método de prueba.The MethodBase.GetMethodBody method is used to obtain a MethodBody object for the test method. La ExceptionHandlingClauses propiedad se usa para obtener una lista de ExceptionHandlingClause objetos y mostrar sus propiedades.The ExceptionHandlingClauses property is used to obtain a list of ExceptionHandlingClause objects and display their properties.

Puede usar Ildasm. exe para examinar el MSIL del ejemplo de código compilado, para ver cómo se calculan los desplazamientos y las longitudes.You can use Ildasm.exe to examine the MSIL for the compiled code example, to see how the offsets and lengths are calculated.

Nota

No todos los idiomas del equipo ExceptionHandlingClauseOptions.Filter pueden generar cláusulas.Not all computer languages can generate ExceptionHandlingClauseOptions.Filter clauses. En el ejemplo Visual Basic se muestra una cláusula de filtro mediante When una expresión Visual Basic, que se omite en los ejemplos de otros lenguajes.The Visual Basic example shows a filter clause, using a Visual Basic When expression, which is omitted from the examples for other languages.

Este código forma parte de un ejemplo más grande que se MethodBody encuentra en el tema de la clase.This code is part of a larger example located in the MethodBody class topic.

#using <System.dll>

using namespace System;
using namespace System::Reflection;

public ref class Example
{
    // The Main method contains code to analyze this method, using
    // the properties and methods of the MethodBody class.
public:
    void MethodBodyExample(Object^ arg)
    {
        // Define some local variables. In addition to these variables,
        // the local variable list includes the variables scoped to 
        // the catch clauses.
        int var1 = 42;
        String^ var2 = "Forty-two";

        try
        {
            // Depending on the input value, throw an ArgumentException or 
            // an ArgumentNullException to test the Catch clauses.
            if (arg == nullptr)
            {
                throw gcnew ArgumentNullException("The argument cannot " +
                    "be null.");
            }
            if (arg->GetType() == String::typeid)
            {
                throw gcnew ArgumentException("The argument cannot " + 
                    "be a string.");
            }        
        }

        // There is no Filter clause in this code example. See the Visual 
        // Basic code for an example of a Filter clause.

        // This catch clause handles the ArgumentException class, and
        // any other class derived from Exception.
        catch (ArgumentException^ ex)
        {
            Console::WriteLine("Ordinary exception-handling clause caught:" +
                " {0}", ex->GetType());
        }        
        finally
        {
            var1 = 3033;
            var2 = "Another string.";
        }
    }
};

int main()
{ 
    // Get method body information.
    MethodInfo^ mi = 
        Example::typeid->GetMethod("MethodBodyExample");

    MethodBody^ mb = mi->GetMethodBody();
    Console::WriteLine("\r\nMethod: {0}", mi);

    // Display the general information included in the 
    // MethodBody object.
    Console::WriteLine("    Local variables are initialized: {0}", 
        mb->InitLocals);
    Console::WriteLine("    Maximum number of items on the operand " +
        "stack: {0}", mb->MaxStackSize);
using System;
using System.Reflection;

public class Example
{
    public static void Main()
    {
        // Get method body information.
        MethodInfo mi = typeof(Example).GetMethod("MethodBodyExample");
        MethodBody mb = mi.GetMethodBody();
        Console.WriteLine("\r\nMethod: {0}", mi);

        // Display the general information included in the 
        // MethodBody object.
        Console.WriteLine("    Local variables are initialized: {0}", 
            mb.InitLocals);
        Console.WriteLine("    Maximum number of items on the operand stack: {0}", 
            mb.MaxStackSize);
Imports System.Reflection

Public Class Example

    Public Shared Sub Main()

        ' Demonstrate the effect of the Visual Basic When keyword, which
        ' generates a Filter clause in the Try block.
        Dim e As New Example()
        Console.WriteLine()
        e.MethodBodyExample("String argument")
        e.MethodBodyExample(Nothing)

        ' Get method body information.
        Dim mi As MethodInfo = _
            GetType(Example).GetMethod("MethodBodyExample")
        Dim mb As MethodBody = mi.GetMethodBody()
        Console.WriteLine(vbCrLf & "Method: {0}", mi)

        ' Display the general information included in the 
        ' MethodBody object.
        Console.WriteLine("    Local variables are initialized: {0}", _
            mb.InitLocals)
        Console.WriteLine("    Maximum number of items on the operand stack: {0}", _
            mb.MaxStackSize)

// Display exception handling clauses.
Console::WriteLine();
for each(ExceptionHandlingClause^ exhc in mb->ExceptionHandlingClauses)
{
    Console::WriteLine(exhc->Flags.ToString());

    // The FilterOffset property is meaningful only for Filter
    // clauses. The CatchType property is not meaningful for 
    // Filter or Finally clauses. 
    switch(exhc->Flags)
    {
    case ExceptionHandlingClauseOptions::Filter:
        Console::WriteLine("        Filter Offset: {0}", 
            exhc->FilterOffset);
        break;
    case ExceptionHandlingClauseOptions::Finally:
        break;
    default:
        Console::WriteLine("    Type of exception: {0}", 
            exhc->CatchType);
        break;
    }

    Console::WriteLine("       Handler Length: {0}",
        exhc->HandlerLength);
    Console::WriteLine("       Handler Offset: {0}", 
        exhc->HandlerOffset);
    Console::WriteLine("     Try Block Length: {0}", exhc->TryLength);
    Console::WriteLine("     Try Block Offset: {0}", exhc->TryOffset);
}

// Display exception handling clauses.
Console.WriteLine();
foreach (ExceptionHandlingClause ehc in mb.ExceptionHandlingClauses)
{
    Console.WriteLine(ehc.Flags.ToString());

    // The FilterOffset property is meaningful only for Filter
    // clauses. The CatchType property is not meaningful for 
    // Filter or Finally clauses. 
    switch (ehc.Flags)
    {
        case ExceptionHandlingClauseOptions.Filter:
            Console.WriteLine("        Filter Offset: {0}", 
                ehc.FilterOffset);
            break;
        case ExceptionHandlingClauseOptions.Finally:
            break;
        default:
            Console.WriteLine("    Type of exception: {0}", 
                ehc.CatchType);
            break;
    }

    Console.WriteLine("       Handler Length: {0}", ehc.HandlerLength);
    Console.WriteLine("       Handler Offset: {0}", ehc.HandlerOffset);
    Console.WriteLine("     Try Block Length: {0}", ehc.TryLength);
    Console.WriteLine("     Try Block Offset: {0}", ehc.TryOffset);
}

' Display exception handling clauses.
Console.WriteLine()
For Each ehc As ExceptionHandlingClause In mb.ExceptionHandlingClauses
    Console.WriteLine(ehc.Flags.ToString())

    ' The FilterOffset property is meaningful only for Filter
    ' clauses. The CatchType property is not meaningful for 
    ' Filter or Finally clauses. 
    Select Case ehc.Flags
        Case ExceptionHandlingClauseOptions.Filter
            Console.WriteLine("        Filter Offset: {0}", _
                ehc.FilterOffset)
        Case ExceptionHandlingClauseOptions.Finally
        Case Else
            Console.WriteLine("    Type of exception: {0}", _
                ehc.CatchType)
    End Select

    Console.WriteLine("       Handler Length: {0}", ehc.HandlerLength)
    Console.WriteLine("       Handler Offset: {0}", ehc.HandlerOffset)
    Console.WriteLine("     Try Block Length: {0}", ehc.TryLength)
    Console.WriteLine("     Try Block Offset: {0}", ehc.TryOffset)
Next
    // The Main method contains code to analyze this method, using
    // the properties and methods of the MethodBody class.
public:
    void MethodBodyExample(Object^ arg)
    {
        // Define some local variables. In addition to these variables,
        // the local variable list includes the variables scoped to 
        // the catch clauses.
        int var1 = 42;
        String^ var2 = "Forty-two";

        try
        {
            // Depending on the input value, throw an ArgumentException or 
            // an ArgumentNullException to test the Catch clauses.
            if (arg == nullptr)
            {
                throw gcnew ArgumentNullException("The argument cannot " +
                    "be null.");
            }
            if (arg->GetType() == String::typeid)
            {
                throw gcnew ArgumentException("The argument cannot " + 
                    "be a string.");
            }        
        }

        // There is no Filter clause in this code example. See the Visual 
        // Basic code for an example of a Filter clause.

        // This catch clause handles the ArgumentException class, and
        // any other class derived from Exception.
        catch (ArgumentException^ ex)
        {
            Console::WriteLine("Ordinary exception-handling clause caught:" +
                " {0}", ex->GetType());
        }        
        finally
        {
            var1 = 3033;
            var2 = "Another string.";
        }
    }
    }

    // The Main method contains code to analyze this method, using
    // the properties and methods of the MethodBody class.
    public void MethodBodyExample(object arg)
    {
        // Define some local variables. In addition to these variables,
        // the local variable list includes the variables scoped to 
        // the catch clauses.
        int var1 = 42;
        string var2 = "Forty-two";

        try
        {
            // Depending on the input value, throw an ArgumentException or 
            // an ArgumentNullException to test the Catch clauses.
            if (arg == null)
            {
                throw new ArgumentNullException("The argument cannot be null.");
            }
            if (arg.GetType() == typeof(string))
            {
                throw new ArgumentException("The argument cannot be a string.");
            }        
        }

        // There is no Filter clause in this code example. See the Visual 
        // Basic code for an example of a Filter clause.

        // This catch clause handles the ArgumentException class, and
        // any other class derived from Exception.
        catch(Exception ex)
        {
            Console.WriteLine("Ordinary exception-handling clause caught: {0}", 
                ex.GetType());
        }        
        finally
        {
            var1 = 3033;
            var2 = "Another string.";
        }
    }
}

// This code example produces output similar to the following:
//
//Method: Void MethodBodyExample(System.Object)
//    Local variables are initialized: True
//    Maximum number of items on the operand stack: 2
    End Sub

    ' This test method is executed at the beginning of Main, to show
    ' how the Filter clause works. The Filter clause is generated by 
    ' a Visual Basic When expression. If arg is Nothing, this method
    ' throws ArgumentNullException, which is caught by the filter
    ' clause. If arg is a string, the method throws ArgumentException,
    ' which does not match the filter clause.
    '
    ' Sub Main also contains code to analyze this method, using 
    ' the properties and methods of the MethodBody class.
    Public Sub MethodBodyExample(ByVal arg As Object)

        ' Define some local variables. In addition to these variables,
        ' the local variable list includes the variables scoped to 
        ' the catch clauses.
        Dim var1 As Integer = 42
        Dim var2 As String = "Forty-two"

        Try
            ' Depending on the input value, throw an ArgumentException or 
            ' an ArgumentNullException to test the Catch clauses.
            '
            If arg Is Nothing Then
                Throw New ArgumentNullException("The argument cannot be Nothing.")
            End If
            If arg.GetType() Is GetType(String) Then
                Throw New ArgumentException("The argument cannot be a string.")
            End If
        
        ' The When expression makes this a filter clause. The expression 
        ' selects only exceptions that derive from the ArgumentException
        ' class. Other exceptions, including ArgumentException itself, 
        ' are not handled by this filter clause.
        Catch ex As ArgumentException _
            When ex.GetType().IsSubclassOf(GetType(ArgumentException))

            Console.WriteLine("Filter clause caught: {0}", ex.GetType())
        
        ' This catch clause handles the ArgumentException class, and
        ' any other class derived from Exception.
        Catch ex As Exception
            Console.WriteLine("Ordinary exception-handling clause caught: {0}", _
                ex.GetType())

        Finally
            var1 = 3033
            var2 = "Another string."
        End Try
    End Sub
End Class

' This code example produces output similar to the following:
'
'Ordinary exception-handling clause caught: System.ArgumentException
'Filter clause caught: System.ArgumentNullException
'
'Method: Void MethodBodyExample(System.Object)
'    Local variables are initialized: True
'    Maximum number of items on the operand stack: 3
//Clause
//    Type of exception: System.ArgumentException
//       Handler Length: 29
//       Handler Offset: 78
//     Try Block Length: 65
//     Try Block Offset: 13
//Finally
//       Handler Length: 13
//       Handler Offset: 113
//     Try Block Length: 100
//     Try Block Offset: 13
//
//Clause
//    Type of exception: System.Exception
//       Handler Length: 21
//       Handler Offset: 70
//     Try Block Length: 61
//     Try Block Offset: 9
//Finally
//       Handler Length: 14
//       Handler Offset: 94
//     Try Block Length: 85
//     Try Block Offset: 9
'
'Filter
'        Filter Offset: 0
'       Handler Length: 19
'       Handler Offset: 99
'     Try Block Length: 45
'     Try Block Offset: 9
'Clause
'    Type of exception: System.Exception
'       Handler Length: 25
'       Handler Offset: 118
'     Try Block Length: 45
'     Try Block Offset: 9
'Finally
'       Handler Length: 13
'       Handler Offset: 153
'     Try Block Length: 144
'     Try Block Offset: 9

Comentarios

La ExceptionHandlingClause clase proporciona información sobre las cláusulas tryde... catch...finallyThe ExceptionHandlingClause class provides information about the clauses in a trycatchfinally bloquear (Try... Catch...Finallyblock (TryCatchFinally en Visual Basic).in Visual Basic). Para obtener una lista de las cláusulas de control de excepciones en un método, MethodInfo obtenga un que represente el método.To get a list of exception-handling clauses in a method, obtain a MethodInfo that represents the method. Utilice el GetMethodBody método para obtener un MethodBody objeto y, a continuación, ExceptionHandlingClauses use la propiedad para obtener la lista de cláusulas.Use the GetMethodBody method to obtain a MethodBody object, and then use the ExceptionHandlingClauses property to get the list of clauses.

Nota

Trabajar con cláusulas de control de excepciones requiere un conocimiento exhaustivo de los metadatos y los formatos de instrucciones del lenguaje intermedio de Microsoft (MSIL).Working with exception-handling clauses requires a thorough understanding of metadata and Microsoft intermediate language (MSIL) instruction formats. Puede encontrar información en la documentación de Common Language Infrastructure (CLI), especialmente "Partition II: Metadata Definition and Semantics (Partición II: definición y semántica de los metadatos)" y "Partition III: CIL Instruction Set (Partición III: conjunto de instrucciones CIL)".Information can be found in the Common Language Infrastructure (CLI) documentation, especially "Partition II: Metadata Definition and Semantics" and "Partition III: CIL Instruction Set". La documentación está disponible en línea; vea ECMA C# and Common Language Infrastructure Standards (Estándares de ECMA C# y Common Language Infrastructure) en MSDN y Standard ECMA-335 - Common Language Infrastructure (CLI) (Estándar ECMA-335: Common Language Infrastructure [CLI]) en el sitio web de Ecma International.The documentation is available online; see ECMA C# and Common Language Infrastructure Standards on MSDN and Standard ECMA-335 - Common Language Infrastructure (CLI) on the Ecma International Web site.

Constructores

ExceptionHandlingClause() ExceptionHandlingClause() ExceptionHandlingClause() ExceptionHandlingClause()

Inicializa una nueva instancia de la clase ExceptionHandlingClause.Initializes a new instance of the ExceptionHandlingClause class.

Propiedades

CatchType CatchType CatchType CatchType

Obtiene el tipo de excepción controlado por esta cláusula.Gets the type of exception handled by this clause.

FilterOffset FilterOffset FilterOffset FilterOffset

Obtiene el desplazamiento dentro del cuerpo del método, en bytes, del código de filtro proporcionado por el usuario.Gets the offset within the method body, in bytes, of the user-supplied filter code.

Flags Flags Flags Flags

Obtiene un valor que indica si esta cláusula de control de excepciones es una cláusula finally, una cláusula filtrada por tipo o una cláusula filtrada por usuario.Gets a value indicating whether this exception-handling clause is a finally clause, a type-filtered clause, or a user-filtered clause.

HandlerLength HandlerLength HandlerLength HandlerLength

Obtiene la longitud, en bytes, del cuerpo de esta cláusula de control de excepciones.Gets the length, in bytes, of the body of this exception-handling clause.

HandlerOffset HandlerOffset HandlerOffset HandlerOffset

Obtiene el desplazamiento dentro del cuerpo del método, en bytes, de esta cláusula de control de excepciones.Gets the offset within the method body, in bytes, of this exception-handling clause.

TryLength TryLength TryLength TryLength

Longitud total, en bytes, del bloque Try que incluye esta cláusula de control de excepciones.The total length, in bytes, of the try block that includes this exception-handling clause.

TryOffset TryOffset TryOffset TryOffset

Desplazamiento dentro del método, en bytes, del bloque Try que incluye esta cláusula de control de excepciones.The offset within the method, in bytes, of the try block that includes this exception-handling clause.

Métodos

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Determina si el objeto especificado es igual al objeto actual.Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Sirve como la función hash predeterminada.Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

Obtiene el Type de la instancia actual.Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Crea una copia superficial del objeto Object actual.Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

Representación de cadena de la cláusula de control de excepciones.A string representation of the exception-handling clause.

Se aplica a

Consulte también: