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Expression.Negate Method (Expression)

Creates a UnaryExpression that represents an arithmetic negation operation.

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

static member Negate : 
        expression:Expression -> UnaryExpression

Parameters

expression
Type: System.Linq.Expressions.Expression

An Expression to set the Operand property equal to.

Return Value

Type: System.Linq.Expressions.UnaryExpression
A UnaryExpression that has the NodeType property equal to Negate and the Operand property set to the specified value.

ExceptionCondition
ArgumentNullException

expression is a null reference (Nothing in Visual Basic).

InvalidOperationException

The unary minus operator is not defined for expression.Type.

The Method property of the resulting UnaryExpression is set to the implementing method. The Type property is set to the type of the node. If the node is lifted, the IsLifted and IsLiftedToNull properties are both true. Otherwise, they are false.

The following rules determine the implementing method for the operation:

  • If expression.Type is a user-defined type that defines the unary minus operator, the MethodInfo that represents that operator is the implementing method.

  • Otherwise, if expression.Type is a numeric type, the implementing method is a null reference (Nothing in Visual Basic).

If the implementing method is not a null reference (Nothing in Visual Basic):

  • If expression.Type is assignable to the argument type 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 and the type of the node is the nullable type that corresponds to the return type of the implementing method:

    • expression.Type is a nullable value type and the corresponding non-nullable value type is equal to the argument type of the implementing method.

    • The return type of the implementing method is a non-nullable value type.

If the implementing method is a null reference (Nothing in Visual Basic), the type of the node is expression.Type. If expression.Type is non-nullable, the node is not lifted. Otherwise, the node is lifted.

The following example demonstrates how to create an expression that represents an arithmetic negation operation.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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