Επεξεργασία

Κοινή χρήση μέσω


Expression.NegateChecked Method

Definition

Creates a UnaryExpression that represents an arithmetic negation operation that has overflow checking.

Overloads

NegateChecked(Expression)

Creates a UnaryExpression that represents an arithmetic negation operation that has overflow checking.

NegateChecked(Expression, MethodInfo)

Creates a UnaryExpression that represents an arithmetic negation operation that has overflow checking. The implementing method can be specified.

NegateChecked(Expression)

Source:
UnaryExpression.cs
Source:
UnaryExpression.cs
Source:
UnaryExpression.cs

Creates a UnaryExpression that represents an arithmetic negation operation that has overflow checking.

public:
 static System::Linq::Expressions::UnaryExpression ^ NegateChecked(System::Linq::Expressions::Expression ^ expression);
public static System.Linq.Expressions.UnaryExpression NegateChecked (System.Linq.Expressions.Expression expression);
static member NegateChecked : System.Linq.Expressions.Expression -> System.Linq.Expressions.UnaryExpression
Public Shared Function NegateChecked (expression As Expression) As UnaryExpression

Parameters

expression
Expression

An Expression to set the Operand property equal to.

Returns

A UnaryExpression that has the NodeType property equal to NegateChecked and the Operand property set to the specified value.

Exceptions

expression is null.

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

Remarks

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.

Implementing Method

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 null.

Node Type and Lifted versus Non-Lifted

If the implementing method is not null:

  • 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 null, the type of the node is expression.Type. If expression.Type is non-nullable, the node is not lifted. Otherwise, the node is lifted.

Applies to

NegateChecked(Expression, MethodInfo)

Source:
UnaryExpression.cs
Source:
UnaryExpression.cs
Source:
UnaryExpression.cs

Creates a UnaryExpression that represents an arithmetic negation operation that has overflow checking. The implementing method can be specified.

public:
 static System::Linq::Expressions::UnaryExpression ^ NegateChecked(System::Linq::Expressions::Expression ^ expression, System::Reflection::MethodInfo ^ method);
public static System.Linq.Expressions.UnaryExpression NegateChecked (System.Linq.Expressions.Expression expression, System.Reflection.MethodInfo method);
public static System.Linq.Expressions.UnaryExpression NegateChecked (System.Linq.Expressions.Expression expression, System.Reflection.MethodInfo? method);
static member NegateChecked : System.Linq.Expressions.Expression * System.Reflection.MethodInfo -> System.Linq.Expressions.UnaryExpression
Public Shared Function NegateChecked (expression As Expression, method As MethodInfo) As UnaryExpression

Parameters

expression
Expression

An Expression to set the Operand property equal to.

method
MethodInfo

A MethodInfo to set the Method property equal to.

Returns

A UnaryExpression that has the NodeType property equal to NegateChecked and the Operand and Method properties set to the specified values.

Exceptions

expression is null.

method is not null and the method it represents returns void, is not static (Shared in Visual Basic), or does not take exactly one argument.

method is null and the unary minus operator is not defined for expression.Type.

-or-

expression.Type (or its corresponding non-nullable type if it is a nullable value type) is not assignable to the argument type of the method represented by method.

Remarks

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.

Implementing Method

The following rules determine the implementing method for the operation:

  • If method is not null and it represents a non-void, static (Shared in Visual Basic) method that takes one argument, it is the implementing method for the node.

  • 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 null.

Node Type and Lifted versus Non-Lifted

If the implementing method is not null:

  • 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 null, the type of the node is expression.Type. If expression.Type is non-nullable, the node is not lifted. Otherwise, the node is lifted.

Applies to