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MemberInitExpression Class

Represents calling a constructor and initializing one or more members of the new object.


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

public sealed class MemberInitExpression : Expression

The MemberInitExpression type exposes the following members.

Public propertySupported by Portable Class LibraryBindingsGets the bindings that describe how to initialize the members of the newly created object.
Public propertyCanReduceGets a value that indicates whether the expression tree node can be reduced. (Overrides Expression.CanReduce.)
Public propertySupported by Portable Class LibraryNewExpressionGets the expression that represents the constructor call.
Public propertyNodeTypeReturns the node type of this Expression. Extension nodes should return Extension when overriding this method. (Overrides Expression.NodeType.)
Public propertyTypeGets the static type of the expression that this Expression represents. (Overrides Expression.Type.)

Protected methodAcceptDispatches to the specific visit method for this node type. For example, MethodCallExpression calls the VisitMethodCall. (Inherited from Expression.)
Public methodSupported by Portable Class LibraryEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodSupported by Portable Class LibraryFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodSupported by Portable Class LibraryGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodSupported by Portable Class LibraryGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodSupported by Portable Class LibraryMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodReduceReduces the MemberInitExpression to a simpler expression. (Overrides Expression.Reduce().)
Public methodReduceAndCheckReduces 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.)
Public methodReduceExtensionsReduces 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.)
Public methodSupported by Portable Class LibraryToStringReturns a textual representation of the Expression. (Inherited from Expression.)
Public methodUpdateCreates 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.
Protected methodVisitChildrenReduces 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.)

Use the MemberInit factory methods to create a MemberInitExpression.

The value of the NodeType property of a MemberInitExpression is MemberInit.

The following example creates a MemberInitExpression that represents the initialization of two members of a new object.

class Animal
    public string Species {get; set;}
    public int Age {get; set;}

public static void CreateMemberInitExpression()
    System.Linq.Expressions.NewExpression newAnimal =

    System.Reflection.MemberInfo speciesMember =
    System.Reflection.MemberInfo ageMember =

    // Create a MemberBinding object for each member
    // that you want to initialize.
    System.Linq.Expressions.MemberBinding speciesMemberBinding =
    System.Linq.Expressions.MemberBinding ageMemberBinding =

    // Create a MemberInitExpression that represents initializing
    // two members of the 'Animal' class.
    System.Linq.Expressions.MemberInitExpression memberInitExpression =


    // This code produces the following output:
    // new Animal() {Species = "horse", Age = 12}

.NET Framework

Supported in: 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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