Expression.Property Method (Expression, String)

Parameters

• expression
  Type: System.Linq.Expressions.Expression
  An Expression whose Type contains a property named propertyName. This can be nulla null reference (Nothing in Visual Basic) for static properties.

• propertyName
  Type: System.String
  The name of a property to be accessed.

Return Value

Type: System.Linq.Expressions.MemberExpression
A MemberExpression that has the NodeType property equal to MemberAccess, the Expression property set to expression, and the Member property set to the PropertyInfo that represents the property denoted by propertyName.

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

Class TestPropertyClass
    Public Property Sample As Integer
End Class

Sub TestProperty()

    Dim obj As New TestPropertyClass()
    obj.Sample = 40

    ' This expression represents accessing a property.
    ' For static properties, the first parameter must be Nothing.
    Dim propertyExpr As Expression = Expression.Property(
          Expression.Constant(obj),
          "sample"
      )

    ' The following statement first creates an expression tree,
    ' then compiles it, and then runs it.
    outputBlock.Text &= Expression.Lambda(Of Func(Of Integer))(propertyExpr).Compile()() & vbCrLf
End Sub

' This code example produces the following output:
'
' 40

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

    class TestPropertyClass
    {
       public int sample { get; set; }
    }

    static void TestProperty(System.Windows.Controls.TextBlock outputBlock)
    {
       TestPropertyClass obj = new TestPropertyClass();
       obj.sample = 40;

       // This expression represents accessing a property.
       // For static fields, the first parameter must be null.
       Expression propertyExpr = Expression.Property(
           Expression.Constant(obj),
           "sample"
       );

       // The following statement first creates an expression tree,
       // then compiles it, and then runs it.
       outputBlock.Text += Expression.Lambda<Func<int>>(propertyExpr).Compile()() + "\n";
    }

    // This code example produces the following output:
    //
    // 40