Expression.Switch Expression.Switch Expression.Switch Expression.Switch Method

Definition

Creates a SwitchExpression that represents a switch statement.

Overloads

Switch(Type, Expression, Expression, MethodInfo, SwitchCase[]) Switch(Type, Expression, Expression, MethodInfo, SwitchCase[]) Switch(Type, Expression, Expression, MethodInfo, SwitchCase[])

Creates a SwitchExpression that represents a switch statement that has a default case.

Switch(Expression, SwitchCase[]) Switch(Expression, SwitchCase[]) Switch(Expression, SwitchCase[]) Switch(Expression, SwitchCase[])

Creates a SwitchExpression that represents a switch statement without a default case.

Switch(Expression, Expression, SwitchCase[]) Switch(Expression, Expression, SwitchCase[]) Switch(Expression, Expression, SwitchCase[]) Switch(Expression, Expression, SwitchCase[])

Creates a SwitchExpression that represents a switch statement that has a default case.

Switch(Expression, Expression, MethodInfo, IEnumerable<SwitchCase>) Switch(Expression, Expression, MethodInfo, IEnumerable<SwitchCase>) Switch(Expression, Expression, MethodInfo, IEnumerable<SwitchCase>) Switch(Expression, Expression, MethodInfo, IEnumerable<SwitchCase>)

Creates a SwitchExpression that represents a switch statement that has a default case.

Switch(Expression, Expression, MethodInfo, SwitchCase[]) Switch(Expression, Expression, MethodInfo, SwitchCase[]) Switch(Expression, Expression, MethodInfo, SwitchCase[]) Switch(Expression, Expression, MethodInfo, SwitchCase[])

Creates a SwitchExpression that represents a switch statement that has a default case.

Switch(Type, Expression, Expression, MethodInfo, IEnumerable<SwitchCase>) Switch(Type, Expression, Expression, MethodInfo, IEnumerable<SwitchCase>) Switch(Type, Expression, Expression, MethodInfo, IEnumerable<SwitchCase>)

Creates a SwitchExpression that represents a switch statement that has a default case.

Switch(Type, Expression, Expression, MethodInfo, SwitchCase[]) Switch(Type, Expression, Expression, MethodInfo, SwitchCase[]) Switch(Type, Expression, Expression, MethodInfo, SwitchCase[])

Creates a SwitchExpression that represents a switch statement that has a default case.

public:
 static System::Linq::Expressions::SwitchExpression ^ Switch(Type ^ type, System::Linq::Expressions::Expression ^ switchValue, System::Linq::Expressions::Expression ^ defaultBody, System::Reflection::MethodInfo ^ comparison, ... cli::array <System::Linq::Expressions::SwitchCase ^> ^ cases);
public static System.Linq.Expressions.SwitchExpression Switch (Type type, System.Linq.Expressions.Expression switchValue, System.Linq.Expressions.Expression defaultBody, System.Reflection.MethodInfo comparison, params System.Linq.Expressions.SwitchCase[] cases);
static member Switch : Type * System.Linq.Expressions.Expression * System.Linq.Expressions.Expression * System.Reflection.MethodInfo * System.Linq.Expressions.SwitchCase[] -> System.Linq.Expressions.SwitchExpression

Parameters

type
Type Type Type Type

The result type of the switch.

switchValue
Expression Expression Expression Expression

The value to be tested against each case.

defaultBody
Expression Expression Expression Expression

The result of the switch if switchValue does not match any of the cases.

comparison
MethodInfo MethodInfo MethodInfo MethodInfo

The equality comparison method to use.

cases
SwitchCase[]

The set of cases for this switch expression.

Returns

Switch(Expression, SwitchCase[]) Switch(Expression, SwitchCase[]) Switch(Expression, SwitchCase[]) Switch(Expression, SwitchCase[])

Creates a SwitchExpression that represents a switch statement without a default case.

public:
 static System::Linq::Expressions::SwitchExpression ^ Switch(System::Linq::Expressions::Expression ^ switchValue, ... cli::array <System::Linq::Expressions::SwitchCase ^> ^ cases);
public static System.Linq.Expressions.SwitchExpression Switch (System.Linq.Expressions.Expression switchValue, params System.Linq.Expressions.SwitchCase[] cases);
static member Switch : System.Linq.Expressions.Expression * System.Linq.Expressions.SwitchCase[] -> System.Linq.Expressions.SwitchExpression
Public Shared Function Switch (switchValue As Expression, ParamArray cases As SwitchCase()) As SwitchExpression

Parameters

switchValue
Expression Expression Expression Expression

The value to be tested against each case.

cases
SwitchCase[]

The set of cases for this switch expression.

Returns

Examples

The following example demonstrates how to create an expression that represents a switch statement without a default case.

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

// An expression that represents the switch value.
ConstantExpression switchValue = Expression.Constant(2);

// This expression represents a switch statement 
// without a default case.
SwitchExpression switchExpr =
    Expression.Switch(
        switchValue,
        new SwitchCase[] {
            Expression.SwitchCase(
                Expression.Call(
                    null,
                    typeof(Console).GetMethod("WriteLine", new Type[] { typeof(String) }),
                    Expression.Constant("First")
                ),
                Expression.Constant(1)
            ),
            Expression.SwitchCase(
                Expression.Call(
                    null,
                    typeof(Console).GetMethod("WriteLine", new Type[] { typeof(String) }),
                    Expression.Constant("Second")
                ),
                Expression.Constant(2)
            )
        }
    );

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

// This code example produces the following output:
//
// Second
' Add the following directive to the file:
' Imports System.Linq.Expressions

' An expression that represents the switch value.
Dim switchValue As ConstantExpression = Expression.Constant(2)

' This expression represents a switch statement 
' without a default case.
Dim switchExpr As SwitchExpression =
Expression.Switch(
    switchValue,
    New SwitchCase() {
        Expression.SwitchCase(
            Expression.Call(
                Nothing,
                GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}),
                Expression.Constant("First")
            ),
            Expression.Constant(1)
        ),
        Expression.SwitchCase(
            Expression.Call(
                Nothing,
                GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}),
                Expression.Constant("Second")
            ),
            Expression.Constant(2)
        )
    }
)

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

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

Remarks

All SwitchCase objects in a SwitchExpression object must have the same type, unless the SwitchExpression has the type void.

Each SwitchCase object has an implicit break statement, which means that there is no implicit fall through from one case label to another.

If switchValue does not match any of the cases, no exception is thrown.

Switch(Expression, Expression, SwitchCase[]) Switch(Expression, Expression, SwitchCase[]) Switch(Expression, Expression, SwitchCase[]) Switch(Expression, Expression, SwitchCase[])

Creates a SwitchExpression that represents a switch statement that has a default case.

public:
 static System::Linq::Expressions::SwitchExpression ^ Switch(System::Linq::Expressions::Expression ^ switchValue, System::Linq::Expressions::Expression ^ defaultBody, ... cli::array <System::Linq::Expressions::SwitchCase ^> ^ cases);
public static System.Linq.Expressions.SwitchExpression Switch (System.Linq.Expressions.Expression switchValue, System.Linq.Expressions.Expression defaultBody, params System.Linq.Expressions.SwitchCase[] cases);
static member Switch : System.Linq.Expressions.Expression * System.Linq.Expressions.Expression * System.Linq.Expressions.SwitchCase[] -> System.Linq.Expressions.SwitchExpression
Public Shared Function Switch (switchValue As Expression, defaultBody As Expression, ParamArray cases As SwitchCase()) As SwitchExpression

Parameters

switchValue
Expression Expression Expression Expression

The value to be tested against each case.

defaultBody
Expression Expression Expression Expression

The result of the switch if switchValue does not match any of the cases.

cases
SwitchCase[]

The set of cases for this switch expression.

Returns

Examples

The following example demonstrates how to create an expression that represents a switch statement that has a default case.

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

// An expression that represents the switch value.
ConstantExpression switchValue = Expression.Constant(3);

// This expression represents a switch statement 
// that has a default case.
SwitchExpression switchExpr =
    Expression.Switch(
        switchValue,
        Expression.Call(
                    null,
                    typeof(Console).GetMethod("WriteLine", new Type[] { typeof(String) }),
                    Expression.Constant("Default")
                ),
        new SwitchCase[] {
            Expression.SwitchCase(
                Expression.Call(
                    null,
                    typeof(Console).GetMethod("WriteLine", new Type[] { typeof(String) }),
                    Expression.Constant("First")
                ),
                Expression.Constant(1)
            ),
            Expression.SwitchCase(
                Expression.Call(
                    null,
                    typeof(Console).GetMethod("WriteLine", new Type[] { typeof(String) }),
                    Expression.Constant("Second")
                ),
                Expression.Constant(2)
            )
        }
    );

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

// This code example produces the following output:
//
// Default
' Add the following directive to the file:
' Imports System.Linq.Expressions

' An expression that represents the switch value.
Dim switchValue As ConstantExpression = Expression.Constant(3)

' This expression represents a switch statement 
' that has a default case.
Dim switchExpr As SwitchExpression =
Expression.Switch(
    switchValue,
    Expression.Call(
                Nothing,
                GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}),
                Expression.Constant("Default")
            ),
    New SwitchCase() {
        Expression.SwitchCase(
            Expression.Call(
                Nothing,
                GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}),
                Expression.Constant("First")
            ),
            Expression.Constant(1)
        ),
        Expression.SwitchCase(
            Expression.Call(
                Nothing,
                GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}),
                Expression.Constant("Second")
            ),
            Expression.Constant(2)
        )
    }
)

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

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

Remarks

All SwitchCase objects in a SwitchExpression object must have the same type, unless the SwitchExpression has the type void.

Each SwitchCase object has an implicit break statement, which means that there is no implicit fall through from one case label to another.

If switchValue does not match any of the cases, the default case represented by defaultBody is run.

Switch(Expression, Expression, MethodInfo, IEnumerable<SwitchCase>) Switch(Expression, Expression, MethodInfo, IEnumerable<SwitchCase>) Switch(Expression, Expression, MethodInfo, IEnumerable<SwitchCase>) Switch(Expression, Expression, MethodInfo, IEnumerable<SwitchCase>)

Creates a SwitchExpression that represents a switch statement that has a default case.

public:
 static System::Linq::Expressions::SwitchExpression ^ Switch(System::Linq::Expressions::Expression ^ switchValue, System::Linq::Expressions::Expression ^ defaultBody, System::Reflection::MethodInfo ^ comparison, System::Collections::Generic::IEnumerable<System::Linq::Expressions::SwitchCase ^> ^ cases);
public static System.Linq.Expressions.SwitchExpression Switch (System.Linq.Expressions.Expression switchValue, System.Linq.Expressions.Expression defaultBody, System.Reflection.MethodInfo comparison, System.Collections.Generic.IEnumerable<System.Linq.Expressions.SwitchCase> cases);
static member Switch : System.Linq.Expressions.Expression * System.Linq.Expressions.Expression * System.Reflection.MethodInfo * seq<System.Linq.Expressions.SwitchCase> -> System.Linq.Expressions.SwitchExpression
Public Shared Function Switch (switchValue As Expression, defaultBody As Expression, comparison As MethodInfo, cases As IEnumerable(Of SwitchCase)) As SwitchExpression

Parameters

switchValue
Expression Expression Expression Expression

The value to be tested against each case.

defaultBody
Expression Expression Expression Expression

The result of the switch if switchValue does not match any of the cases.

comparison
MethodInfo MethodInfo MethodInfo MethodInfo

The equality comparison method to use.

cases
IEnumerable<SwitchCase>

The set of cases for this switch expression.

Returns

Switch(Expression, Expression, MethodInfo, SwitchCase[]) Switch(Expression, Expression, MethodInfo, SwitchCase[]) Switch(Expression, Expression, MethodInfo, SwitchCase[]) Switch(Expression, Expression, MethodInfo, SwitchCase[])

Creates a SwitchExpression that represents a switch statement that has a default case.

public:
 static System::Linq::Expressions::SwitchExpression ^ Switch(System::Linq::Expressions::Expression ^ switchValue, System::Linq::Expressions::Expression ^ defaultBody, System::Reflection::MethodInfo ^ comparison, ... cli::array <System::Linq::Expressions::SwitchCase ^> ^ cases);
public static System.Linq.Expressions.SwitchExpression Switch (System.Linq.Expressions.Expression switchValue, System.Linq.Expressions.Expression defaultBody, System.Reflection.MethodInfo comparison, params System.Linq.Expressions.SwitchCase[] cases);
static member Switch : System.Linq.Expressions.Expression * System.Linq.Expressions.Expression * System.Reflection.MethodInfo * System.Linq.Expressions.SwitchCase[] -> System.Linq.Expressions.SwitchExpression
Public Shared Function Switch (switchValue As Expression, defaultBody As Expression, comparison As MethodInfo, ParamArray cases As SwitchCase()) As SwitchExpression

Parameters

switchValue
Expression Expression Expression Expression

The value to be tested against each case.

defaultBody
Expression Expression Expression Expression

The result of the switch if switchValue does not match any of the cases.

comparison
MethodInfo MethodInfo MethodInfo MethodInfo

The equality comparison method to use.

cases
SwitchCase[]

The set of cases for this switch expression.

Returns

Switch(Type, Expression, Expression, MethodInfo, IEnumerable<SwitchCase>) Switch(Type, Expression, Expression, MethodInfo, IEnumerable<SwitchCase>) Switch(Type, Expression, Expression, MethodInfo, IEnumerable<SwitchCase>)

Creates a SwitchExpression that represents a switch statement that has a default case.

public:
 static System::Linq::Expressions::SwitchExpression ^ Switch(Type ^ type, System::Linq::Expressions::Expression ^ switchValue, System::Linq::Expressions::Expression ^ defaultBody, System::Reflection::MethodInfo ^ comparison, System::Collections::Generic::IEnumerable<System::Linq::Expressions::SwitchCase ^> ^ cases);
public static System.Linq.Expressions.SwitchExpression Switch (Type type, System.Linq.Expressions.Expression switchValue, System.Linq.Expressions.Expression defaultBody, System.Reflection.MethodInfo comparison, System.Collections.Generic.IEnumerable<System.Linq.Expressions.SwitchCase> cases);
static member Switch : Type * System.Linq.Expressions.Expression * System.Linq.Expressions.Expression * System.Reflection.MethodInfo * seq<System.Linq.Expressions.SwitchCase> -> System.Linq.Expressions.SwitchExpression

Parameters

type
Type Type Type Type

The result type of the switch.

switchValue
Expression Expression Expression Expression

The value to be tested against each case.

defaultBody
Expression Expression Expression Expression

The result of the switch if switchValue does not match any of the cases.

comparison
MethodInfo MethodInfo MethodInfo MethodInfo

The equality comparison method to use.

cases
IEnumerable<SwitchCase>

The set of cases for this switch expression.

Returns

Applies to