Expression.Assign Method (Expression, Expression)
.NET Framework (current version)
Creates a BinaryExpression that represents an assignment operation.
Assembly: System.Core (in System.Core.dll)
Public Shared Function Assign ( left As Expression, right As Expression ) As BinaryExpression
Parameters
- left
-
Type:
System.Linq.Expressions.Expression
An Expression to set the Left property equal to.
- right
-
Type:
System.Linq.Expressions.Expression
An Expression to set the Right property equal to.
Return Value
Type: System.Linq.Expressions.BinaryExpressionA BinaryExpression that has the NodeType property equal to Assign and the Left and Right properties set to the specified values.
The Assign expression copies a value for value types, and it copies a reference for reference types.
The following code example shows how to create an expression that represents an assignment operation.
' 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!
Universal Windows Platform
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 4.0
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 4.0
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
Show: