InvocationExpression Class
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Represents an expression that applies a delegate or lambda expression to a list of argument expressions.
Assembly: System.Core (in System.Core.dll)
The InvocationExpression type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | 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. (Overrides Expression.NodeType.) |
![]() | Type | Gets the static type of the expression that this Expression represents. (Overrides Expression.Type.) |
| Name | Description | |
|---|---|---|
![]() | Accept | Dispatches to the specific visit method for this node type. For example, MethodCallExpression calls the VisitMethodCall. (Inherited from Expression.) |
![]() | Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.) |
![]() | GetHashCode | Serves as a hash function for a particular type. (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 | 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 | 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.) |
The following example creates an InvocationExpression that represents invoking a lambda expression with specified arguments.
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)) outputBlock.Text &= invocationExpression.ToString() & vbCrLf ' This code produces the following output: ' ' Invoke((num1, num2) => ((num1 + num2) > 1000),539,281)
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