Expression.Assign(Expression, Expression) Expression.Assign(Expression, Expression) Expression.Assign(Expression, Expression) Expression.Assign(Expression, Expression) Method

定義

代入演算を表す BinaryExpression を作成します。Creates a BinaryExpression that represents an assignment operation.

public:
 static System::Linq::Expressions::BinaryExpression ^ Assign(System::Linq::Expressions::Expression ^ left, System::Linq::Expressions::Expression ^ right);
public static System.Linq.Expressions.BinaryExpression Assign (System.Linq.Expressions.Expression left, System.Linq.Expressions.Expression right);
static member Assign : System.Linq.Expressions.Expression * System.Linq.Expressions.Expression -> System.Linq.Expressions.BinaryExpression
Public Shared Function Assign (left As Expression, right As Expression) As BinaryExpression

パラメーター

left
Expression Expression Expression Expression

Expression プロパティを等しく設定する LeftAn Expression to set the Left property equal to.

right
Expression Expression Expression Expression

Expression プロパティを等しく設定する RightAn Expression to set the Right property equal to.

戻り値

BinaryExpression と等しい NodeType プロパティと、指定した値に設定された Assign プロパティおよび Left プロパティを含む RightA BinaryExpression that has the NodeType property equal to Assign and the Left and Right properties set to the specified values.

次のコード例では、代入演算を表す式を作成する方法を示します。The following code example shows how to create an expression that represents an assignment operation.

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

// To demonstrate the assignment operation, we create a variable.
ParameterExpression variableExpr = Expression.Variable(typeof(String), "sampleVar");

// This expression represents the assignment of a value
// to a variable expression.
// It copies a value for value types, and
// copies a reference for reference types.
Expression assignExpr = Expression.Assign(
    variableExpr,
    Expression.Constant("Hello World!")
    );

// The block expression allows for executing several expressions sequentually.
// In this block, we pass the variable expression as a parameter,
// and then assign this parameter a value in the assign expression.
Expression blockExpr = Expression.Block(
    new ParameterExpression[] { variableExpr },
    assignExpr
    );

// Print out the assign expression.
Console.WriteLine(assignExpr.ToString());

// The following statement first creates an expression tree,
// then compiles it, and then executes it.  
Console.WriteLine(Expression.Lambda<Func<String>>(blockExpr).Compile()());

// This code example produces the following output:
//
// (sampleVar = "Hello World!")
// Hello World!

' Add the following directive to your file:
' Imports System.Linq.Expressions 

' To demonstrate the assignment operation, create a variable.
Dim variableExpr As ParameterExpression = Expression.Variable(GetType(String), "sampleVar")

' This expression represents the assignment of a value
' to a variable expression.
' It copies a value for value types, and it
' copies a reference for reference types.
Dim assignExpr As Expression = Expression.Assign(
    variableExpr,
    Expression.Constant("Hello World!")
    )

' The block expression allows for executing several expressions sequentually.
' In this block, you pass the variable expression as a parameter,
' and then assign this parameter a value in the assign expression.
Dim blockExpr As Expression = Expression.Block(
      New ParameterExpression() {variableExpr}, assignExpr
      )

' Print the assign expression.
Console.WriteLine(assignExpr.ToString())

' The following statement first creates an expression tree,
' then compiles it, and then executes it. 
Console.WriteLine(Expression.Lambda(Of Func(Of String))(blockExpr).Compile()())

' This code example produces the following output:
'
' (sampleVar = "Hello World!")
' Hello World!

注釈

Assign式は、値の型の値をコピーし、参照型への参照をコピーします。The Assign expression copies a value for value types, and it copies a reference for reference types.

適用対象