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CodeCatchClause Class

Represents a catch exception block of a try/catch statement.

For a list of all members of this type, see CodeCatchClause Members.

System.Object
   System.CodeDom.CodeCatchClause

[Visual Basic]
<Serializable>
<ClassInterface(ClassInterfaceType.AutoDispatch)>
<ComVisible(True)>
Public Class CodeCatchClause
[C#]
[Serializable]
[ClassInterface(ClassInterfaceType.AutoDispatch)]
[ComVisible(true)]
public class CodeCatchClause
[C++]
[Serializable]
[ClassInterface(ClassInterfaceType::AutoDispatch)]
[ComVisible(true)]
public __gc class CodeCatchClause
[JScript]
public
   Serializable
 ClassInterface(ClassInterfaceType.AutoDispatch)
 ComVisible(true)
class CodeCatchClause

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Remarks

CodeCatchClause can be used to represent a catch exception block of a try/catch statement.

The CatchExceptionType property specifies the type of exception to catch. The LocalName property specifies a name for the variable representing the exception that has been caught. The Statements collection property contains the statements for the catch block.

Example

[Visual Basic, C#, C++] The following example code demonstrates using CodeCatchClause objects to define exception handling clauses of a try...catch block.

[Visual Basic] 
' 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 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");
'        }
'    }

[C#] 
// 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");
//        }
//    }


[C++] 
// Declares a type to contain a try...catch block.
CodeTypeDeclaration* type1 = new CodeTypeDeclaration(S"TryCatchTest");

// Defines a method that throws an exception of type System.ApplicationException.
CodeMemberMethod* method1 = new CodeMemberMethod();
method1->Name = S"ThrowApplicationException";
CodePrimitiveExpression* temp[] = {new CodePrimitiveExpression(S"Test Application Exception")};
method1->Statements->Add( new CodeThrowExceptionStatement( 
    new CodeObjectCreateExpression(S"System.ApplicationException", temp) ) );
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(), S"ThrowApplicationException", 0 ) );
constructor1->Statements->Add( try1 );                    

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

// Defines a catch clause for any remaining unhandled exception types.
CodeCatchClause* catch2 = new CodeCatchClause(S"ex");
catch2->Statements->Add( new CodeCommentStatement(S"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(S"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");
//        }
//    }

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Namespace: System.CodeDom

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

Assembly: System (in System.dll)

See Also

CodeCatchClause Members | System.CodeDom Namespace | CodeCatchClauseCollection | CodeTryCatchFinallyStatement

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