CodeCatchClause Classe

Definição

Namespace:

System.CodeDom

Assembly:

System.CodeDom.dll

Pacote:

System.CodeDom v8.0.0

Origem:

CodeCatchClause.cs

Representa um bloco de exceção catch de uma instrução try/catch.

public ref class CodeCatchClause

public class CodeCatchClause

type CodeCatchClause = class

Public Class CodeCatchClause

Herança

Object

CodeCatchClause

Exemplos

O código de exemplo a seguir demonstra o uso CodeCatchClause de objetos para definir cláusulas de tratamento de exceção de uma tentativa... bloco catch.

// Declares a type to contain a try...catch block.
CodeTypeDeclaration^ type1 = gcnew CodeTypeDeclaration( "TryCatchTest" );

// Defines a method that throws an exception of type System.ApplicationException.
CodeMemberMethod^ method1 = gcnew CodeMemberMethod;
method1->Name = "ThrowApplicationException";
array<CodePrimitiveExpression^>^temp = {gcnew CodePrimitiveExpression( "Test Application Exception" )};
method1->Statements->Add( gcnew CodeThrowExceptionStatement( gcnew CodeObjectCreateExpression( "System.ApplicationException",temp ) ) );
type1->Members->Add( method1 );

// Defines a constructor that calls the ThrowApplicationException method from a try block.
CodeConstructor^ constructor1 = gcnew CodeConstructor;
constructor1->Attributes = MemberAttributes::Public;
type1->Members->Add( constructor1 );

// Defines a try statement that calls the ThrowApplicationException method.
CodeTryCatchFinallyStatement^ try1 = gcnew CodeTryCatchFinallyStatement;
try1->TryStatements->Add( gcnew CodeMethodInvokeExpression( gcnew CodeThisReferenceExpression,"ThrowApplicationException", nullptr ) );
constructor1->Statements->Add( try1 );

// Defines a catch clause for exceptions of type ApplicationException.
CodeCatchClause^ catch1 = gcnew CodeCatchClause( "ex",gcnew CodeTypeReference( "System.ApplicationException" ) );
catch1->Statements->Add( gcnew CodeCommentStatement( "Handle any System.ApplicationException here." ) );
try1->CatchClauses->Add( catch1 );

// Defines a catch clause for any remaining unhandled exception types.
CodeCatchClause^ catch2 = gcnew CodeCatchClause( "ex" );
catch2->Statements->Add( gcnew CodeCommentStatement( "Handle any other exception type here." ) );
try1->CatchClauses->Add( catch2 );

// Defines a finally block by adding to the FinallyStatements collection.
try1->FinallyStatements->Add( gcnew CodeCommentStatement( "Handle any finally block statements." ) );

// A C# code generator produces the following source code for the preceeding example code:
//    public class TryCatchTest 
//    {
//        
//        public TryCatchTest() 
//        {
//            try 
//            {
//                this.ThrowApplicationException();
//            }
//            catch (System.ApplicationException ex) 
//            {
//                // Handle any System.ApplicationException here.
//            }
//            catch (System.Exception ex) 
//            {
//                // Handle any other exception type here.
//            }
//          finally {
//                // Handle any finally block statements.
//            }
//        }
//        
//        private void ThrowApplicationException() 
//        {
//            throw new System.ApplicationException("Test Application Exception");
//        }
//    }

// Declares a type to contain a try...catch block.
CodeTypeDeclaration type1 = new CodeTypeDeclaration("TryCatchTest");

// Defines a method that throws an exception of type System.ApplicationException.
CodeMemberMethod method1 = new CodeMemberMethod();
method1.Name = "ThrowApplicationException";
method1.Statements.Add( new CodeThrowExceptionStatement(
    new CodeObjectCreateExpression("System.ApplicationException", new CodePrimitiveExpression("Test Application Exception")) ) );
type1.Members.Add( method1 );

// Defines a constructor that calls the ThrowApplicationException method from a try block.
CodeConstructor constructor1 = new CodeConstructor();
constructor1.Attributes = MemberAttributes.Public;
type1.Members.Add( constructor1 );

// Defines a try statement that calls the ThrowApplicationException method.
CodeTryCatchFinallyStatement try1 = new CodeTryCatchFinallyStatement();
try1.TryStatements.Add( new CodeMethodInvokeExpression( new CodeThisReferenceExpression(), "ThrowApplicationException" ) );
constructor1.Statements.Add( try1 );

// Defines a catch clause for exceptions of type ApplicationException.
CodeCatchClause catch1 = new CodeCatchClause("ex", new CodeTypeReference("System.ApplicationException"));
catch1.Statements.Add( new CodeCommentStatement("Handle any System.ApplicationException here.") );
try1.CatchClauses.Add( catch1 );

// Defines a catch clause for any remaining unhandled exception types.
CodeCatchClause catch2 = new CodeCatchClause("ex");
catch2.Statements.Add( new CodeCommentStatement("Handle any other exception type here.") );
try1.CatchClauses.Add( catch2 );

// Defines a finally block by adding to the FinallyStatements collection.
try1.FinallyStatements.Add( new CodeCommentStatement("Handle any finally block statements.") );

// A C# code generator produces the following source code for the preceeding example code:

//    public class TryCatchTest
//    {
//
//        public TryCatchTest()
//        {
//            try
//            {
//                this.ThrowApplicationException();
//            }
//            catch (System.ApplicationException ex)
//            {
//                // Handle any System.ApplicationException here.
//            }
//            catch (System.Exception ex)
//            {
//                // Handle any other exception type here.
//            }
//          finally {
//                // Handle any finally block statements.
//            }
//        }
//
//        private void ThrowApplicationException()
//        {
//            throw new System.ApplicationException("Test Application Exception");
//        }
//    }

' Declares a type to contain a try...catch block.
Dim type1 As New CodeTypeDeclaration("TryCatchTest")

' Defines a method that throws an exception of type System.ApplicationException.
Dim method1 As New CodeMemberMethod()
method1.Name = "ThrowApplicationException"
method1.Statements.Add(New CodeThrowExceptionStatement( _
    New CodeObjectCreateExpression("System.ApplicationException", New CodePrimitiveExpression("Test Application Exception"))))
type1.Members.Add(method1)

' Defines a constructor that calls the ThrowApplicationException method from a try block.
Dim constructor1 As New CodeConstructor()
constructor1.Attributes = MemberAttributes.Public
type1.Members.Add(constructor1)

' Defines a try statement that calls the ThrowApplicationException method.
Dim try1 As New CodeTryCatchFinallyStatement()
try1.TryStatements.Add(New CodeMethodInvokeExpression(New CodeThisReferenceExpression(), "ThrowApplicationException"))
constructor1.Statements.Add(try1)

' Defines a catch clause for exceptions of type ApplicationException.
Dim catch1 As New CodeCatchClause("ex", New CodeTypeReference("System.ApplicationException"))
catch1.Statements.Add(New CodeCommentStatement("Handle any System.ApplicationException here."))
try1.CatchClauses.Add(catch1)

' Defines a catch clause for any remaining unhandled exception types.
Dim catch2 As New CodeCatchClause("ex")
catch2.Statements.Add(New CodeCommentStatement("Handle any other exception type here."))
try1.CatchClauses.Add(catch2)

' Defines a finally block by adding to the FinallyStatements collection.
try1.FinallyStatements.Add(New CodeCommentStatement("Handle any finally block statements."))

' A Visual Basic code generator produces the following Visual Basic source 
' code for the preceeding example code:

'            '------------------------------------------------------------------------------
'            ' <auto-generated>
'            '     This code was generated by a tool.
'            '     Runtime Version:2.0.50727.42
'            '
'            '     Changes to this file may cause incorrect behavior and will be lost if
'            '     the code is regenerated.
'            ' </auto-generated>
'            '------------------------------------------------------------------------------

'Option Strict Off
'Option Explicit On

'            'Namespace Samples

'            Public Class TryCatchTest

'                Public Sub New()
'                    MyBase.New()
'                    Try
'                        Me.ThrowApplicationException()
'                    Catch ex As System.ApplicationException
'                        'Handle any System.ApplicationException here.
'                    Catch ex As System.Exception
'                        'Handle any other exception type here.
'                    Finally
'                        'Handle any finally block statements.
'                    End Try
'                End Sub

'                Private Sub ThrowApplicationException()
'                    Throw New System.ApplicationException("Test Application Exception")
'                End Sub
'            End Class
'        End Namespace

Comentários

CodeCatchClause pode ser usado para representar um catch bloco de exceção de uma try/catch instrução .

A CatchExceptionType propriedade especifica o tipo de exceção a ser capturada. A LocalName propriedade especifica um nome para a variável que representa a exceção que foi capturada. A Statements propriedade da coleção contém as instruções do catch bloco.

Construtores

CodeCatchClause()	Inicializa uma nova instância da classe CodeCatchClause.
CodeCatchClause(String)	Inicializa uma nova instância da classe CodeCatchClause usando o nome da variável local especificado para a exceção.
CodeCatchClause(String, CodeTypeReference)	Inicializa uma nova instância da classe CodeCatchClause usando o nome da variável local especificado para a exceção e o tipo de exceção.
CodeCatchClause(String, CodeTypeReference, CodeStatement[])	Inicializa uma nova instância da classe CodeCatchClause usando o nome da variável local especificado para a exceção, o tipo de exceção e a coleção de instruções.

Propriedades

CatchExceptionType	Obtém ou define o tipo da exceção a manipular com o bloco catch.
LocalName	Obtém ou define o nome da variável da exceção tratada pela cláusula catch.
Statements	Obtém as instruções dentro do bloco catch.

Métodos

Equals(Object)	Determina se o objeto especificado é igual ao objeto atual. (Herdado de Object)
GetHashCode()	Serve como a função de hash padrão. (Herdado de Object)
GetType()	Obtém o Type da instância atual. (Herdado de Object)
MemberwiseClone()	Cria uma cópia superficial do Object atual. (Herdado de Object)
ToString()	Retorna uma cadeia de caracteres que representa o objeto atual. (Herdado de Object)

Confira também

• CodeCatchClauseCollection
• CodeTryCatchFinallyStatement