Expression.MemberInit Method (NewExpression, IEnumerable<MemberBinding>)

Represents an expression that creates a new object and initializes a property of the object.

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

public static MemberInitExpression MemberInit(
	NewExpression newExpression,
	IEnumerable<MemberBinding> bindings


Type: System.Linq.Expressions.NewExpression

A NewExpression to set the NewExpression property equal to.

Type: System.Collections.Generic.IEnumerable<MemberBinding>

An IEnumerable<T> that contains MemberBinding objects to use to populate the Bindings collection.

Return Value

Type: System.Linq.Expressions.MemberInitExpression
A MemberInitExpression that has the NodeType property equal to MemberInit and the NewExpression and Bindings properties set to the specified values.


newExpression or bindings is null.


The Member property of an element of bindings does not represent a member of the type that newExpression.Type represents.

The Type property of the resulting MemberInitExpression is equal to the Type property of newExpression.

The following example demonstrates an expression that creates a new object and initializes a property of the object.

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

class TestMemberInitClass
    public int sample { get; set; }

static void MemberInit()
    // This expression creates a new TestMemberInitClass object 
    // and assigns 10 to its sample property.
    Expression testExpr = Expression.MemberInit(
        new List<MemberBinding>() {
            Expression.Bind(typeof(TestMemberInitClass).GetMember("sample")[0], Expression.Constant(10))

    // The following statement first creates an expression tree, 
    // then compiles it, and then runs it. 
    var test = Expression.Lambda<Func<TestMemberInitClass>>(testExpr).Compile()();

// This code example produces the following output: 
// 10

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Portable Class Library

Supported in: Portable Class Library
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