CodeCatchClause Klas

Definitie

public ref class CodeCatchClause

[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.AutoDispatch)]
[System.Runtime.InteropServices.ComVisible(true)]
[System.Serializable]
public class CodeCatchClause

[<System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.AutoDispatch)>]
[<System.Runtime.InteropServices.ComVisible(true)>]
[<System.Serializable>]
type CodeCatchClause = class

Public Class CodeCatchClause

Overname

Object

CodeCatchClause

Kenmerken

ClassInterfaceAttribute ComVisibleAttribute SerializableAttribute

Voorbeelden

De volgende voorbeeldcode laat zien hoe u CodeCatchClause objecten gebruikt om component voor uitzonderingsafhandeling van een poging te definiëren... catch block.

// 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

Opmerkingen

CodeCatchClause kan worden gebruikt om een catch uitzonderingsblok van een try/catch instructie weer te geven.

De CatchExceptionType eigenschap geeft het type uitzondering op dat moet worden onderschept. De LocalName eigenschap geeft een naam op voor de variabele die de uitzondering vertegenwoordigt die is gevangen. De Statements verzamelingseigenschap bevat de instructies voor het catch blok.

Zie ook

• CodeCatchClauseCollection
• CodeTryCatchFinallyStatement