Expression.Constant Method (Object, Type)

Parameters

• value
  Type: System.Object
  An Object to set the Value property equal to.

• type
  Type: System.Type
  A Type to set the Type property equal to.

Return Value

Type: System.Linq.Expressions.ConstantExpression
A ConstantExpression that has the NodeType property equal to Constant and the Value and Type properties set to the specified values.

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

' This expression represents a constant value, 
' for which you can explicitly specify the type. 
' This can be used, for example, for defining constants of a nullable type.
Dim constantExpr As Expression = Expression.Constant(
                            Nothing,
                            GetType(Double?)
                        )

' Print the expression.
outputBlock.Text &= constantExpr.ToString() & vbCrLf

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

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

       // This expression represents a constant value, 
       // for which you can explicitly specify the type. 
       // This can be used, for example, for defining constants of a nullable type.
       Expression constantExpr = Expression.Constant(
                                   null,
                                   typeof(double?)
                               );

       // Print out the expression.
       outputBlock.Text += constantExpr.ToString() + "\n";

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