Expression.Return Method

Definition

Creates a GotoExpression representing a return statement.

Overloads

Return(LabelTarget)

Creates a GotoExpression representing a return statement.

Return(LabelTarget, Expression)

Creates a GotoExpression representing a return statement. The value passed to the label upon jumping can be specified.

Return(LabelTarget, Type)

Creates a GotoExpression representing a return statement with the specified type.

Return(LabelTarget, Expression, Type)

Creates a GotoExpression representing a return statement with the specified type. The value passed to the label upon jumping can be specified.

Return(LabelTarget)

Creates a GotoExpression representing a return statement.

public:
 static System::Linq::Expressions::GotoExpression ^ Return(System::Linq::Expressions::LabelTarget ^ target);
public static System.Linq.Expressions.GotoExpression Return (System.Linq.Expressions.LabelTarget target);
static member Return : System.Linq.Expressions.LabelTarget -> System.Linq.Expressions.GotoExpression
Public Shared Function Return (target As LabelTarget) As GotoExpression

Parameters

target
LabelTarget

The LabelTarget that the GotoExpression will jump to.

Returns

A GotoExpression with Kind equal to Return, the Target property set to target, and a null value to be passed to the target label upon jumping.

Return(LabelTarget, Expression)

Creates a GotoExpression representing a return statement. The value passed to the label upon jumping can be specified.

public:
 static System::Linq::Expressions::GotoExpression ^ Return(System::Linq::Expressions::LabelTarget ^ target, System::Linq::Expressions::Expression ^ value);
public static System.Linq.Expressions.GotoExpression Return (System.Linq.Expressions.LabelTarget target, System.Linq.Expressions.Expression value);
static member Return : System.Linq.Expressions.LabelTarget * System.Linq.Expressions.Expression -> System.Linq.Expressions.GotoExpression
Public Shared Function Return (target As LabelTarget, value As Expression) As GotoExpression

Parameters

target
LabelTarget

The LabelTarget that the GotoExpression will jump to.

value
Expression

The value that will be passed to the associated label upon jumping.

Returns

A GotoExpression with Kind equal to Continue, the Target property set to target, and value to be passed to the target label upon jumping.

Examples

The following example demonstrates how to create an expression that contains the Return method.

// Add the following directive to the file:
// using System.Linq.Expressions;  

// A label expression of the void type that is the target for Expression.Return().
LabelTarget returnTarget = Expression.Label();

// This block contains a GotoExpression that represents a return statement with no value.
// It transfers execution to a label expression that is initialized with the same LabelTarget as the GotoExpression.
// The types of the GotoExpression, label expression, and LabelTarget must match.
BlockExpression blockExpr =
    Expression.Block(
        Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("Return")),
        Expression.Return(returnTarget),
        Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("Other Work")),
        Expression.Label(returnTarget)
    );

// The following statement first creates an expression tree,
// then compiles it, and then runs it.
Expression.Lambda<Action>(blockExpr).Compile()();

// This code example produces the following output:
//
// Return

// "Other Work" is not printed because 
// the Return expression transfers execution from Expression.Return(returnTarget)
// to Expression.Label(returnTarget).
' Add the following directive to the file:
' Imports System.Linq.Expressions  

' A label expression of the void type that is the target for Expression.Return().
Dim returnTarget As LabelTarget = Expression.Label()

' This block contains a GotoExpression that represents a return statement with no value.
' It transfers execution to a label expression that is initialized with the same LabelTarget as the GotoExpression.
' The types of the GotoExpression, label expression, and LabelTarget must match.
Dim blockExpr As BlockExpression =
      Expression.Block(
          Expression.Call(GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}), Expression.Constant("Return")),
          Expression.Return(returnTarget),
          Expression.Call(GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}), Expression.Constant("Other Work")),
          Expression.Label(returnTarget)
      )

' The following statement first creates an expression tree,
' then compiles it, and then runs it.
Expression.Lambda(Of Action)(blockExpr).Compile()()

' This code example produces the following output:
'
' Return

' "Other Work" is not printed because 
' the Return expression transfers execution from Return(returnTarget)
' to Expression.Label(returnTarget).

Return(LabelTarget, Type)

Creates a GotoExpression representing a return statement with the specified type.

public:
 static System::Linq::Expressions::GotoExpression ^ Return(System::Linq::Expressions::LabelTarget ^ target, Type ^ type);
public static System.Linq.Expressions.GotoExpression Return (System.Linq.Expressions.LabelTarget target, Type type);
static member Return : System.Linq.Expressions.LabelTarget * Type -> System.Linq.Expressions.GotoExpression

Parameters

target
LabelTarget

The LabelTarget that the GotoExpression will jump to.

type
Type

An Type to set the Type property equal to.

Returns

A GotoExpression with Kind equal to Return, the Target property set to target, the Type property set to type, and a null value to be passed to the target label upon jumping.

Return(LabelTarget, Expression, Type)

Creates a GotoExpression representing a return statement with the specified type. The value passed to the label upon jumping can be specified.

public:
 static System::Linq::Expressions::GotoExpression ^ Return(System::Linq::Expressions::LabelTarget ^ target, System::Linq::Expressions::Expression ^ value, Type ^ type);
public static System.Linq.Expressions.GotoExpression Return (System.Linq.Expressions.LabelTarget target, System.Linq.Expressions.Expression value, Type type);
static member Return : System.Linq.Expressions.LabelTarget * System.Linq.Expressions.Expression * Type -> System.Linq.Expressions.GotoExpression

Parameters

target
LabelTarget

The LabelTarget that the GotoExpression will jump to.

value
Expression

The value that will be passed to the associated label upon jumping.

type
Type

An Type to set the Type property equal to.

Returns

A GotoExpression with Kind equal to Continue, the Target property set to target, the Type property set to type, and value to be passed to the target label upon jumping.

Applies to