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Expression.Subtract Method (Expression, Expression, MethodInfo)

Creates a BinaryExpression that represents an arithmetic subtraction operation that does not have overflow checking.

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

'Declaration
Public Shared Function Subtract ( _
	left As Expression, _
	right As Expression, _
	method As MethodInfo _
) As BinaryExpression

Parameters

left
Type: System.Linq.Expressions.Expression
A Expression to set the Left property equal to.
right
Type: System.Linq.Expressions.Expression
A Expression to set the Right property equal to.
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 Subtract and the Left, Right, 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 subtraction 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 and IsLiftedToNull properties are both true. Otherwise, they are 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 for the node.

  • Otherwise, if the Type property of either left or right represents a user-defined type that overloads the subtraction 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 and the type of the node is the nullable type that corresponds to the return type of the implementing method:

    • 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 a non-nullable value type.

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 the result type of the predefined subtraction operator.

  • If left.Type and right.Type are both nullable, the node is lifted. The type of the node is the nullable type that corresponds to the result type of the predefined subtraction operator.

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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