Expression.GreaterThan Method (Expression, Expression, Boolean, MethodInfo)
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Creates a BinaryExpression that represents a "greater than" numeric comparison. The implementing method can be specified.
Assembly: System.Core (in System.Core.dll)
'Declaration Public Shared Function GreaterThan ( _ left As Expression, _ right As Expression, _ liftToNull As Boolean, _ method As MethodInfo _ ) 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.
- liftToNull
- Type: System.Boolean
true to set IsLiftedToNull to true; false to set IsLiftedToNull to false.
- method
- Type: System.Reflection.MethodInfo
A MethodInfo to set the Method property equal to.
Return Value
Type: System.Linq.Expressions.BinaryExpressionA BinaryExpression that has the NodeType property equal to GreaterThan and the Left, Right, IsLiftedToNull, and Method properties set to the specified values.
| Exception | Condition |
|---|---|
| ArgumentNullException | left or right is Nothing. |
| ArgumentException | method is not Nothing and the method it represents returns void, is not static (Shared in Visual Basic), or does not take exactly two arguments. |
| InvalidOperationException | method is Nothing and the "greater than" operator is not defined for left.Type and right.Type. |
The resulting BinaryExpression has the Method property set to the implementing method. The Type property is set to the type of the node. If the node is lifted, the IsLifted property is true and the IsLiftedToNull property is equal to liftToNull. Otherwise, they are both false. The Conversion property is Nothing.
The following information describes the implementing method, the node type, and whether a node is lifted.
Implementing Method
The following rules determine the implementing method for the operation :
If method is not Nothing and it represents a non-void, static (Shared in Visual Basic) method that takes two arguments, it is the implementing method.
Otherwise, if the Type property of either left or right represents a user-defined type that overloads the "greater than" operator, the MethodInfo that represents that method is the implementing method.
Otherwise, if left.Type and right.Type are numeric types, the implementing method is Nothing.
Node Type and Lifted versus Non-Lifted
If the implementing method is not Nothing:
If left.Type and right.Type are assignable to the corresponding argument types of the implementing method, the node is not lifted. The type of the node is the return type of the implementing method.
If the following two conditions are satisfied, the node is lifted; also, the type of the node is nullable Boolean if liftToNull is true or Boolean if liftToNull is false:
left.Type and right.Type are both value types of which at least one is nullable and the corresponding non-nullable types are equal to the corresponding argument types of the implementing method.
The return type of the implementing method is Boolean.
If the implementing method is Nothing: