InvocationExpression Class

Definition

Represents an expression that applies a delegate or lambda expression to a list of argument expressions.

public ref class InvocationExpression sealed : System::Linq::Expressions::Expression, System::Linq::Expressions::IArgumentProvider
public sealed class InvocationExpression : System.Linq.Expressions.Expression, System.Linq.Expressions.IArgumentProvider
type InvocationExpression = class
    inherit Expression
    interface IArgumentProvider
Public NotInheritable Class InvocationExpression
Inherits Expression
Implements IArgumentProvider
Inheritance
InvocationExpression
Implements

Examples

The following example creates an InvocationExpression that represents invoking a lambda expression with specified arguments.

System.Linq.Expressions.Expression<Func<int, int, bool>> largeSumTest =
    (num1, num2) => (num1 + num2) > 1000;

// Create an InvocationExpression that represents applying
// the arguments '539' and '281' to the lambda expression 'largeSumTest'.
System.Linq.Expressions.InvocationExpression invocationExpression =
    System.Linq.Expressions.Expression.Invoke(
        largeSumTest,
        System.Linq.Expressions.Expression.Constant(539),
        System.Linq.Expressions.Expression.Constant(281));

Console.WriteLine(invocationExpression.ToString());

// This code produces the following output:
//
// Invoke((num1, num2) => ((num1 + num2) > 1000),539,281)
Dim largeSumTest As System.Linq.Expressions.Expression(Of System.Func(Of Integer, Integer, Boolean)) = _
    Function(num1, num2) (num1 + num2) > 1000

' Create an InvocationExpression that represents applying
' the arguments '539' and '281' to the lambda expression 'largeSumTest'.
Dim invocationExpression As System.Linq.Expressions.InvocationExpression = _
    System.Linq.Expressions.Expression.Invoke( _
        largeSumTest, _
        System.Linq.Expressions.Expression.Constant(539), _
        System.Linq.Expressions.Expression.Constant(281))

Console.WriteLine(invocationExpression.ToString())

' This code produces the following output:
'
' Invoke((num1, num2) => ((num1 + num2) > 1000),539,281)

Remarks

Use the Invoke factory methods to create an InvocationExpression.

The NodeType of an InvocationExpression is Invoke.

Properties

Arguments

Gets the arguments that the delegate or lambda expression is applied to.

CanReduce

Indicates that the node can be reduced to a simpler node. If this returns true, Reduce() can be called to produce the reduced form.

(Inherited from Expression)
Expression

Gets the delegate or lambda expression to be applied.

NodeType

Returns the node type of this expression. Extension nodes should return Extension when overriding this method.

Type

Gets the static type of the expression that this Expression represents.

Methods

Accept(ExpressionVisitor)

Dispatches to the specific visit method for this node type. For example, MethodCallExpression calls the VisitMethodCall(MethodCallExpression).

(Inherited from Expression)
Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
Reduce()

Reduces this node to a simpler expression. If CanReduce returns true, this should return a valid expression. This method can return another node which itself must be reduced.

(Inherited from Expression)
ReduceAndCheck()

Reduces this node to a simpler expression. If CanReduce returns true, this should return a valid expression. This method can return another node which itself must be reduced.

(Inherited from Expression)
ReduceExtensions()

Reduces the expression to a known node type (that is not an Extension node) or just returns the expression if it is already a known type.

(Inherited from Expression)
ToString()

Returns a textual representation of the Expression.

(Inherited from Expression)
Update(Expression, IEnumerable<Expression>)

Creates a new expression that is like this one, but using the supplied children. If all of the children are the same, it will return this expression.

VisitChildren(ExpressionVisitor)

Reduces the node and then calls the visitor delegate on the reduced expression. The method throws an exception if the node is not reducible.

(Inherited from Expression)

Explicit Interface Implementations

IArgumentProvider.ArgumentCount

Returns the number of arguments to the expression tree node. You should not use this member. It is only public due to assembly refactoring, and it is used internally for performance optimizations.

IArgumentProvider.GetArgument(Int32)

Returns the argument at index, throwing if index is out of bounds. You should not use this member. It is only public due to assembly refactoring, and it is used internally for performance optimizations.

Applies to