Expression.Parameter Methode

public:
 static System::Linq::Expressions::ParameterExpression ^ Parameter(Type ^ type, System::String ^ name);

public static System.Linq.Expressions.ParameterExpression Parameter(Type type, string name);

static member Parameter : Type * string -> System.Linq.Expressions.ParameterExpression

Public Shared Function Parameter (type As Type, name As String) As ParameterExpression

Parameter

Gibt zurück

A ParameterExpression that has the NodeType property equal to Parameter and the TypeName properties set to the specified values.

Ausnahmen

public:
 static System::Linq::Expressions::ParameterExpression ^ Parameter(Type ^ type);

public static System.Linq.Expressions.ParameterExpression Parameter(Type type);

static member Parameter : Type -> System.Linq.Expressions.ParameterExpression

Public Shared Function Parameter (type As Type) As ParameterExpression

Parameter

Gibt zurück

Ein ParameterExpression Knoten mit dem angegebenen Namen und Typ.

Beispiele

Im folgenden Beispiel wird veranschaulicht, wie ein MethodCallExpression Objekt erstellt wird, das den Wert eines ParameterExpression Objekts druckt.

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

// Creating a parameter for the expression tree.
ParameterExpression param = Expression.Parameter(typeof(int));

// Creating an expression for the method call and specifying its parameter.
MethodCallExpression methodCall = Expression.Call(
    typeof(Console).GetMethod("WriteLine", new Type[] { typeof(int) }),
    param
);

// The following statement first creates an expression tree,
// then compiles it, and then runs it.
Expression.Lambda<Action<int>>(
    methodCall,
    new ParameterExpression[] { param }
).Compile()(10);

// This code example produces the following output:
//
// 10

' 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