Expression.Decrement 方法
定義
重要
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創造一個 UnaryExpression ,代表表達式減1的結果。
多載
| 名稱 | Description |
|---|---|
| Decrement(Expression) |
創造一個 UnaryExpression ,代表表達式減1的結果。 |
| Decrement(Expression, MethodInfo) |
創造一個 UnaryExpression ,代表表達式減1的結果。 |
Decrement(Expression)
創造一個 UnaryExpression ,代表表達式減1的結果。
public:
static System::Linq::Expressions::UnaryExpression ^ Decrement(System::Linq::Expressions::Expression ^ expression);
public static System.Linq.Expressions.UnaryExpression Decrement(System.Linq.Expressions.Expression expression);
static member Decrement : System.Linq.Expressions.Expression -> System.Linq.Expressions.UnaryExpression
Public Shared Function Decrement (expression As Expression) As UnaryExpression
參數
- expression
- Expression
然後 Expression 減少。
傳回
A UnaryExpression 代表遞減後的表達式。
範例
以下程式碼範例展示了如何建立一個從給定值中減去 1 的表達式。
// Add the following directive to your file:
// using System.Linq.Expressions;
double num = 5.5;
// This expression represents a decrement operation
// that subtracts 1 from a value.
Expression decrementExpr = Expression.Decrement(
Expression.Constant(num)
);
// Print expression.
Console.WriteLine(decrementExpr.ToString());
// The following statement first creates an expression tree,
// then compiles it, and then executes it.
Console.WriteLine(
Expression.Lambda<Func<double>>(decrementExpr).Compile()());
// The value of the variable did not change,
// because the expression is functional.
Console.WriteLine("object: " + num);
// This code example produces the following output:
//
// Decrement(5.5)
// 4.5
// object: 5.5
' Add the following directive to your file:
' Imports System.Linq.Expressions
Dim num As Double = 5.5
' This expression represents a decrement operation
' that subtracts 1 from a value.
Dim decrementExpr As Expression = Expression.Decrement(
Expression.Constant(num)
)
' Print the expression.
Console.WriteLine(decrementExpr.ToString())
' The following statement first creates an expression tree,
' then compiles it, and then executes it.
Console.WriteLine(
Expression.Lambda(Of Func(Of Double))(decrementExpr).Compile()())
' The value of the variable did not change,
' because the expression is functional.
Console.WriteLine("object: " & num)
' This code example produces the following output:
'
' Decrement(5.5)
' 4.5
' object: 5.5
備註
此表達式是函數式,不會改變傳遞給它的物件值。
適用於
Decrement(Expression, MethodInfo)
創造一個 UnaryExpression ,代表表達式減1的結果。
public:
static System::Linq::Expressions::UnaryExpression ^ Decrement(System::Linq::Expressions::Expression ^ expression, System::Reflection::MethodInfo ^ method);
public static System.Linq.Expressions.UnaryExpression Decrement(System.Linq.Expressions.Expression expression, System.Reflection.MethodInfo method);
public static System.Linq.Expressions.UnaryExpression Decrement(System.Linq.Expressions.Expression expression, System.Reflection.MethodInfo? method);
static member Decrement : System.Linq.Expressions.Expression * System.Reflection.MethodInfo -> System.Linq.Expressions.UnaryExpression
Public Shared Function Decrement (expression As Expression, method As MethodInfo) As UnaryExpression
參數
- expression
- Expression
然後 Expression 減少。
- method
- MethodInfo
代表實作方法的 A MethodInfo 。
傳回
A UnaryExpression 代表遞減後的表達式。
備註
此表達式是函數式,不會改變傳遞給它的物件值。