Expression.Parameter Method (Type)
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Creates a ParameterExpression node that can be used to identify a parameter or a variable in an expression tree.
Assembly: System.Core (in System.Core.dll)
Parameters
- type
- Type: System.Type
The type of the parameter or variable.
Return Value
Type: System.Linq.Expressions.ParameterExpressionA ParameterExpression node with the specified name and type.
The following example demonstrates how to create a MethodCallExpression object that prints the value of a ParameterExpression object.
' Add the following directive to the file: ' Imports System.Linq.Expressions ' Creating a parameter for the expression tree. Dim param As ParameterExpression = Expression.Parameter(GetType(Integer)) ' Creating an expression for the method call and specifying its parameter. Dim methodCall As MethodCallExpression = Expression.Call( GetType(Console).GetMethod("WriteLine", New Type() {GetType(Integer)}), param ) ' Compiling and invoking the methodCall expression. Expression.Lambda(Of Action(Of Integer))( methodCall, New ParameterExpression() {param} ).Compile()(10) ' This code example produces the following output: ' ' 10
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