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SwitchExpression Class

.NET Framework (current version)
 

Represents a control expression that handles multiple selections by passing control to SwitchCase.

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

System.Object
  System.Linq.Expressions.Expression
    System.Linq.Expressions.SwitchExpression

public sealed class SwitchExpression : Expression

NameDescription
System_CAPS_pubpropertyCanReduce

Indicates that the node can be reduced to a simpler node. If this returns true, Reduce() can be called to produce the reduced form.(Inherited from Expression.)

System_CAPS_pubpropertyCases

Gets the collection of SwitchCase objects for the switch.

System_CAPS_pubpropertyComparison

Gets the equality comparison method, if any.

System_CAPS_pubpropertyDefaultBody

Gets the test for the switch.

System_CAPS_pubpropertyNodeType

Returns the node type of this Expression. Extension nodes should return Extension when overriding this method.(Overrides Expression.NodeType.)

System_CAPS_pubpropertySwitchValue

Gets the test for the switch.

System_CAPS_pubpropertyType

Gets the static type of the expression that this Expression represents.(Overrides Expression.Type.)

NameDescription
System_CAPS_protmethodAccept(ExpressionVisitor)

Dispatches to the specific visit method for this node type. For example, MethodCallExpression calls theVisitMethodCall.(Inherited from Expression.)

System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodReduce()

Reduces this node to a simpler expression. If CanReduce returns true, this should return a valid expression. This method can return another node which itself must be reduced.(Inherited from Expression.)

System_CAPS_pubmethodReduceAndCheck()

Reduces this node to a simpler expression. If CanReduce returns true, this should return a valid expression. This method can return another node which itself must be reduced.(Inherited from Expression.)

System_CAPS_pubmethodReduceExtensions()

Reduces the expression to a known node type (that is not an Extension node) or just returns the expression if it is already a known type.(Inherited from Expression.)

System_CAPS_pubmethodToString()

Returns a textual representation of the Expression.(Inherited from Expression.)

System_CAPS_pubmethodUpdate(Expression, IEnumerable<SwitchCase>, Expression)

Creates a new expression that is like this one, but using the supplied children. If all of the children are the same, it will return this expression.

System_CAPS_protmethodVisitChildren(ExpressionVisitor)

Reduces the node and then calls the visitor delegate on the reduced expression. The method throws an exception if the node is not reducible.(Inherited from Expression.)

The following example demonstrates how to create an expression that represents a switch statement that has a default case by using the Switch method.

// 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

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 4.0
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1

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

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