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Expression.NotEqual Method (Expression, Expression, Boolean, MethodInfo)

Creates a BinaryExpression that represents an inequality comparison.

Namespace:  System.Linq.Expressions
Assembly:  System.Core (in System.Core.dll)

'Declaration
Public Shared Function NotEqual ( _
	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.BinaryExpression
A BinaryExpression that has the NodeType property equal to NotEqual and the Left, Right, IsLiftedToNull, and Method properties set to the specified values.

ExceptionCondition
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 inequality 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 inequality operator, the MethodInfo that represents that method is the implementing method.

  • Otherwise, 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:

  • If left.Type and right.Type are both non-nullable, the node is not lifted. The type of the node is Boolean.

  • If left.Type and right.Type are both nullable, the node is lifted. The type of the node is nullable Boolean if liftToNull is true or Boolean if liftToNull is false.

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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