CodeCatchClause Classe

Definizione

Spazio dei nomi:

System.CodeDom

Assembly:

System.CodeDom.dll

Pacchetto:

System.CodeDom v8.0.0

Source:

CodeCatchClause.cs

Rappresenta un blocco di eccezioni catch di un'istruzione try/catch.

public ref class CodeCatchClause

public class CodeCatchClause

type CodeCatchClause = class

Public Class CodeCatchClause

Ereditarietà

Object

CodeCatchClause

Esempio

Il codice di esempio seguente illustra l'uso di CodeCatchClause oggetti per definire le clausole di gestione delle eccezioni di un tentativo... blocco 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

Commenti

CodeCatchClause può essere usato per rappresentare un catch blocco di eccezioni di un'istruzione try/catch .

La CatchExceptionType proprietà specifica il tipo di eccezione da rilevare. La LocalName proprietà specifica un nome per la variabile che rappresenta l'eccezione rilevata. La Statements proprietà collection contiene le istruzioni per il catch blocco.

Costruttori

CodeCatchClause()	Inizializza una nuova istanza della classe CodeCatchClause.
CodeCatchClause(String)	Consente di inizializzare una nuova istanza della classe CodeCatchClause utilizzando il nome della variabile locale specificato per l'eccezione.
CodeCatchClause(String, CodeTypeReference)	Consente di inizializzare una nuova istanza della classe CodeCatchClause utilizzando il nome della variabile locale per l'eccezione e il tipo di eccezione specificati.
CodeCatchClause(String, CodeTypeReference, CodeStatement[])	Consente di inizializzare una nuova istanza della classe CodeCatchClause utilizzando il nome della variabile locale per l'eccezione, il tipo di eccezione e l'insieme di istruzioni specificati.

Proprietà

CatchExceptionType	Ottiene o imposta il tipo di eccezione da gestire con il blocco catch.
LocalName	Ottiene o imposta il nome della variabile dell'eccezione gestita dalla clausola catch.
Statements	Ottiene le istruzioni all'interno del blocco catch.

Metodi

Equals(Object)	Determina se l'oggetto specificato è uguale all'oggetto corrente. (Ereditato da Object)
GetHashCode()	Funge da funzione hash predefinita. (Ereditato da Object)
GetType()	Ottiene l'oggetto Type dell'istanza corrente. (Ereditato da Object)
MemberwiseClone()	Crea una copia superficiale dell'oggetto Object corrente. (Ereditato da Object)
ToString()	Restituisce una stringa che rappresenta l'oggetto corrente. (Ereditato da Object)

Vedi anche

• CodeCatchClauseCollection
• CodeTryCatchFinallyStatement