Expression.TryCatchFinally Method

Creates a TryExpression representing a try block with any number of catch statements and a finally block.

Namespace:  System.Linq.Expressions
Assembly:  System.Core (in System.Core.dll)

'Declaration
Public Shared Function TryCatchFinally ( _
	body As Expression, _
	finally As Expression, _
	ParamArray handlers As CatchBlock() _
) As TryExpression

Parameters

body
Type: System.Linq.Expressions.Expression
The body of the try block.
finally
Type: System.Linq.Expressions.Expression
The body of the finally block.
handlers
Type: System.Linq.Expressions.CatchBlock()
The array of zero or more CatchBlock expressions representing the catch statements to be associated with the try block.

The following example demonstrates how to create a TryExpression object that contains a catch statement and a finally statement.


        ' Add the following directive to the file:
        ' Imports System.Linq.Expressions 

        ' A TryExpression object that has a catch statement and a finally statement.
        ' The return types of the try block and all catch blocks must be the same.
        Dim tryCatchExpr As TryExpression =
            Expression.TryCatchFinally(
                Expression.Block(
                    Expression.Throw(Expression.Constant(New DivideByZeroException())),
                    Expression.Constant("Try block")
                 ),
            Expression.Call(
                GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}),
                Expression.Constant("Finally block")
            ),
            Expression.Catch(
                GetType(DivideByZeroException),
                Expression.Constant("Catch block")
            )
        )

        ' The following statement first creates an expression tree,
        ' then compiles it, and then runs it.
        ' If the exception is caught, 
        ' the result of the TryExpression is the last statement 
        ' of the corresponding catch statement.
        outputBlock.Text &= Expression.Lambda(Of Func(Of String))(tryCatchExpr).Compile()() & vbCrLf

        ' This code example produces the following output:
        '
        ' Finally block
        ' Catch block



Silverlight

Supported in: 5, 4

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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