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Expression.Block Método

Definición

Crea una interfaz BlockExpression.

Sobrecargas

Block(Type, IEnumerable<ParameterExpression>, IEnumerable<Expression>)

Crea un objeto BlockExpression que contiene las variables y expresiones dadas.

Block(Expression, Expression, Expression)

Crea un objeto BlockExpression que contiene tres expresiones y que no tiene variables.

Block(Expression, Expression, Expression, Expression, Expression)

Crea un objeto BlockExpression que contiene cinco expresiones y que no tiene variables.

Block(Type, IEnumerable<ParameterExpression>, Expression[])

Crea un objeto BlockExpression que contiene las variables y expresiones dadas.

Block(Type, Expression[])

Crea un objeto BlockExpression que contiene las expresiones dadas, no tiene variables y tiene el tipo de resultado específico.

Block(Expression, Expression, Expression, Expression)

Crea un objeto BlockExpression que contiene cuatro expresiones y que no tiene variables.

Block(Expression, Expression)

Crea un objeto BlockExpression que contiene dos expresiones y que no tiene variables.

Block(IEnumerable<ParameterExpression>, Expression[])

Crea un objeto BlockExpression que contiene las variables y expresiones dadas.

Block(IEnumerable<ParameterExpression>, IEnumerable<Expression>)

Crea un objeto BlockExpression que contiene las variables y expresiones dadas.

Block(Expression[])

Crea un objeto BlockExpression que contiene las expresiones dadas y que no tiene variables.

Block(IEnumerable<Expression>)

Crea un objeto BlockExpression que contiene las expresiones dadas y que no tiene variables.

Block(Type, IEnumerable<Expression>)

Crea un objeto BlockExpression que contiene las expresiones dadas, no tiene variables y tiene el tipo de resultado específico.

Block(Type, IEnumerable<ParameterExpression>, IEnumerable<Expression>)

Source:
BlockExpression.cs
Source:
BlockExpression.cs
Source:
BlockExpression.cs

Crea un objeto BlockExpression que contiene las variables y expresiones dadas.

public:
 static System::Linq::Expressions::BlockExpression ^ Block(Type ^ type, System::Collections::Generic::IEnumerable<System::Linq::Expressions::ParameterExpression ^> ^ variables, System::Collections::Generic::IEnumerable<System::Linq::Expressions::Expression ^> ^ expressions);
public static System.Linq.Expressions.BlockExpression Block (Type type, System.Collections.Generic.IEnumerable<System.Linq.Expressions.ParameterExpression> variables, System.Collections.Generic.IEnumerable<System.Linq.Expressions.Expression> expressions);
public static System.Linq.Expressions.BlockExpression Block (Type type, System.Collections.Generic.IEnumerable<System.Linq.Expressions.ParameterExpression>? variables, System.Collections.Generic.IEnumerable<System.Linq.Expressions.Expression> expressions);
static member Block : Type * seq<System.Linq.Expressions.ParameterExpression> * seq<System.Linq.Expressions.Expression> -> System.Linq.Expressions.BlockExpression
Public Shared Function Block (type As Type, variables As IEnumerable(Of ParameterExpression), expressions As IEnumerable(Of Expression)) As BlockExpression

Parámetros

type
Type

Tipo de resultado del bloque.

variables
IEnumerable<ParameterExpression>

Variables del bloque.

expressions
IEnumerable<Expression>

Expresiones del bloque.

Devoluciones

Objeto BlockExpression creado.

Se aplica a

Block(Expression, Expression, Expression)

Source:
BlockExpression.cs
Source:
BlockExpression.cs
Source:
BlockExpression.cs

Crea un objeto BlockExpression que contiene tres expresiones y que no tiene variables.

public:
 static System::Linq::Expressions::BlockExpression ^ Block(System::Linq::Expressions::Expression ^ arg0, System::Linq::Expressions::Expression ^ arg1, System::Linq::Expressions::Expression ^ arg2);
public static System.Linq.Expressions.BlockExpression Block (System.Linq.Expressions.Expression arg0, System.Linq.Expressions.Expression arg1, System.Linq.Expressions.Expression arg2);
static member Block : System.Linq.Expressions.Expression * System.Linq.Expressions.Expression * System.Linq.Expressions.Expression -> System.Linq.Expressions.BlockExpression
Public Shared Function Block (arg0 As Expression, arg1 As Expression, arg2 As Expression) As BlockExpression

Parámetros

arg0
Expression

Primera expresión del bloque.

arg1
Expression

Segunda expresión del bloque.

arg2
Expression

Tercera expresión del bloque.

Devoluciones

Objeto BlockExpression creado.

Comentarios

Cuando se ejecuta la expresión de bloque, devuelve el valor de la última expresión del bloque.

Se aplica a

Block(Expression, Expression, Expression, Expression, Expression)

Source:
BlockExpression.cs
Source:
BlockExpression.cs
Source:
BlockExpression.cs

Crea un objeto BlockExpression que contiene cinco expresiones y que no tiene variables.

public:
 static System::Linq::Expressions::BlockExpression ^ Block(System::Linq::Expressions::Expression ^ arg0, System::Linq::Expressions::Expression ^ arg1, System::Linq::Expressions::Expression ^ arg2, System::Linq::Expressions::Expression ^ arg3, System::Linq::Expressions::Expression ^ arg4);
public static System.Linq.Expressions.BlockExpression Block (System.Linq.Expressions.Expression arg0, System.Linq.Expressions.Expression arg1, System.Linq.Expressions.Expression arg2, System.Linq.Expressions.Expression arg3, System.Linq.Expressions.Expression arg4);
static member Block : System.Linq.Expressions.Expression * System.Linq.Expressions.Expression * System.Linq.Expressions.Expression * System.Linq.Expressions.Expression * System.Linq.Expressions.Expression -> System.Linq.Expressions.BlockExpression
Public Shared Function Block (arg0 As Expression, arg1 As Expression, arg2 As Expression, arg3 As Expression, arg4 As Expression) As BlockExpression

Parámetros

arg0
Expression

Primera expresión del bloque.

arg1
Expression

Segunda expresión del bloque.

arg2
Expression

Tercera expresión del bloque.

arg3
Expression

Cuarta expresión del bloque.

arg4
Expression

Quinta expresión del bloque.

Devoluciones

Objeto BlockExpression creado.

Comentarios

Cuando se ejecuta la expresión de bloque, devuelve el valor de la última expresión del bloque.

Se aplica a

Block(Type, IEnumerable<ParameterExpression>, Expression[])

Source:
BlockExpression.cs
Source:
BlockExpression.cs
Source:
BlockExpression.cs

Crea un objeto BlockExpression que contiene las variables y expresiones dadas.

public:
 static System::Linq::Expressions::BlockExpression ^ Block(Type ^ type, System::Collections::Generic::IEnumerable<System::Linq::Expressions::ParameterExpression ^> ^ variables, ... cli::array <System::Linq::Expressions::Expression ^> ^ expressions);
public static System.Linq.Expressions.BlockExpression Block (Type type, System.Collections.Generic.IEnumerable<System.Linq.Expressions.ParameterExpression> variables, params System.Linq.Expressions.Expression[] expressions);
public static System.Linq.Expressions.BlockExpression Block (Type type, System.Collections.Generic.IEnumerable<System.Linq.Expressions.ParameterExpression>? variables, params System.Linq.Expressions.Expression[] expressions);
static member Block : Type * seq<System.Linq.Expressions.ParameterExpression> * System.Linq.Expressions.Expression[] -> System.Linq.Expressions.BlockExpression
Public Shared Function Block (type As Type, variables As IEnumerable(Of ParameterExpression), ParamArray expressions As Expression()) As BlockExpression

Parámetros

type
Type

Tipo de resultado del bloque.

variables
IEnumerable<ParameterExpression>

Variables del bloque.

expressions
Expression[]

Expresiones del bloque.

Devoluciones

Objeto BlockExpression creado.

Se aplica a

Block(Type, Expression[])

Source:
BlockExpression.cs
Source:
BlockExpression.cs
Source:
BlockExpression.cs

Crea un objeto BlockExpression que contiene las expresiones dadas, no tiene variables y tiene el tipo de resultado específico.

public:
 static System::Linq::Expressions::BlockExpression ^ Block(Type ^ type, ... cli::array <System::Linq::Expressions::Expression ^> ^ expressions);
public static System.Linq.Expressions.BlockExpression Block (Type type, params System.Linq.Expressions.Expression[] expressions);
static member Block : Type * System.Linq.Expressions.Expression[] -> System.Linq.Expressions.BlockExpression
Public Shared Function Block (type As Type, ParamArray expressions As Expression()) As BlockExpression

Parámetros

type
Type

Tipo de resultado del bloque.

expressions
Expression[]

Expresiones del bloque.

Devoluciones

Objeto BlockExpression creado.

Se aplica a

Block(Expression, Expression, Expression, Expression)

Source:
BlockExpression.cs
Source:
BlockExpression.cs
Source:
BlockExpression.cs

Crea un objeto BlockExpression que contiene cuatro expresiones y que no tiene variables.

public:
 static System::Linq::Expressions::BlockExpression ^ Block(System::Linq::Expressions::Expression ^ arg0, System::Linq::Expressions::Expression ^ arg1, System::Linq::Expressions::Expression ^ arg2, System::Linq::Expressions::Expression ^ arg3);
public static System.Linq.Expressions.BlockExpression Block (System.Linq.Expressions.Expression arg0, System.Linq.Expressions.Expression arg1, System.Linq.Expressions.Expression arg2, System.Linq.Expressions.Expression arg3);
static member Block : System.Linq.Expressions.Expression * System.Linq.Expressions.Expression * System.Linq.Expressions.Expression * System.Linq.Expressions.Expression -> System.Linq.Expressions.BlockExpression
Public Shared Function Block (arg0 As Expression, arg1 As Expression, arg2 As Expression, arg3 As Expression) As BlockExpression

Parámetros

arg0
Expression

Primera expresión del bloque.

arg1
Expression

Segunda expresión del bloque.

arg2
Expression

Tercera expresión del bloque.

arg3
Expression

Cuarta expresión del bloque.

Devoluciones

Objeto BlockExpression creado.

Comentarios

Cuando se ejecuta la expresión de bloque, devuelve el valor de la última expresión del bloque.

Se aplica a

Block(Expression, Expression)

Source:
BlockExpression.cs
Source:
BlockExpression.cs
Source:
BlockExpression.cs

Crea un objeto BlockExpression que contiene dos expresiones y que no tiene variables.

public:
 static System::Linq::Expressions::BlockExpression ^ Block(System::Linq::Expressions::Expression ^ arg0, System::Linq::Expressions::Expression ^ arg1);
public static System.Linq.Expressions.BlockExpression Block (System.Linq.Expressions.Expression arg0, System.Linq.Expressions.Expression arg1);
static member Block : System.Linq.Expressions.Expression * System.Linq.Expressions.Expression -> System.Linq.Expressions.BlockExpression
Public Shared Function Block (arg0 As Expression, arg1 As Expression) As BlockExpression

Parámetros

arg0
Expression

Primera expresión del bloque.

arg1
Expression

Segunda expresión del bloque.

Devoluciones

Objeto BlockExpression creado.

Comentarios

Cuando se ejecuta la expresión de bloque, devuelve el valor de la última expresión del bloque.

Se aplica a

Block(IEnumerable<ParameterExpression>, Expression[])

Source:
BlockExpression.cs
Source:
BlockExpression.cs
Source:
BlockExpression.cs

Crea un objeto BlockExpression que contiene las variables y expresiones dadas.

public:
 static System::Linq::Expressions::BlockExpression ^ Block(System::Collections::Generic::IEnumerable<System::Linq::Expressions::ParameterExpression ^> ^ variables, ... cli::array <System::Linq::Expressions::Expression ^> ^ expressions);
public static System.Linq.Expressions.BlockExpression Block (System.Collections.Generic.IEnumerable<System.Linq.Expressions.ParameterExpression> variables, params System.Linq.Expressions.Expression[] expressions);
public static System.Linq.Expressions.BlockExpression Block (System.Collections.Generic.IEnumerable<System.Linq.Expressions.ParameterExpression>? variables, params System.Linq.Expressions.Expression[] expressions);
static member Block : seq<System.Linq.Expressions.ParameterExpression> * System.Linq.Expressions.Expression[] -> System.Linq.Expressions.BlockExpression
Public Shared Function Block (variables As IEnumerable(Of ParameterExpression), ParamArray expressions As Expression()) As BlockExpression

Parámetros

variables
IEnumerable<ParameterExpression>

Variables del bloque.

expressions
Expression[]

Expresiones del bloque.

Devoluciones

Objeto BlockExpression creado.

Comentarios

Cuando se ejecuta la expresión de bloque, devuelve el valor de la última expresión del bloque.

Se aplica a

Block(IEnumerable<ParameterExpression>, IEnumerable<Expression>)

Source:
BlockExpression.cs
Source:
BlockExpression.cs
Source:
BlockExpression.cs

Crea un objeto BlockExpression que contiene las variables y expresiones dadas.

public:
 static System::Linq::Expressions::BlockExpression ^ Block(System::Collections::Generic::IEnumerable<System::Linq::Expressions::ParameterExpression ^> ^ variables, System::Collections::Generic::IEnumerable<System::Linq::Expressions::Expression ^> ^ expressions);
public static System.Linq.Expressions.BlockExpression Block (System.Collections.Generic.IEnumerable<System.Linq.Expressions.ParameterExpression> variables, System.Collections.Generic.IEnumerable<System.Linq.Expressions.Expression> expressions);
public static System.Linq.Expressions.BlockExpression Block (System.Collections.Generic.IEnumerable<System.Linq.Expressions.ParameterExpression>? variables, System.Collections.Generic.IEnumerable<System.Linq.Expressions.Expression> expressions);
static member Block : seq<System.Linq.Expressions.ParameterExpression> * seq<System.Linq.Expressions.Expression> -> System.Linq.Expressions.BlockExpression
Public Shared Function Block (variables As IEnumerable(Of ParameterExpression), expressions As IEnumerable(Of Expression)) As BlockExpression

Parámetros

variables
IEnumerable<ParameterExpression>

Variables del bloque.

expressions
IEnumerable<Expression>

Expresiones del bloque.

Devoluciones

Objeto BlockExpression creado.

Ejemplos

En el ejemplo de código siguiente se muestra cómo pasar un parámetro a una expresión de bloque y procesar este parámetro dentro de un bloque.

// Add the following directive to your file:
// using System.Linq.Expressions;

// This block has a parameter expression
// that represents a variable within the block scope.
// It assigns a value to the variable,
// and then adds a constant to the assigned value.

ParameterExpression varExpr = Expression.Variable(typeof(int), "sampleVar");
BlockExpression blockExpr = Expression.Block(
    new ParameterExpression[] { varExpr },
    Expression.Assign(varExpr, Expression.Constant(1)),
    Expression.Add(varExpr, Expression.Constant(5))
);

// Print out the expressions from the block expression.
Console.WriteLine("The expressions from the block expression:");
foreach (var expr in blockExpr.Expressions)
    Console.WriteLine(expr.ToString());

Console.WriteLine("The result of executing the expression tree:");
// The following statement first creates an expression tree,
// then compiles it, and then executes it.
Console.WriteLine(
    Expression.Lambda<Func<int>>(blockExpr).Compile()());

// This code example produces the following output:
// The expressions from the block expression:
// (sampleVar = 1)
// (sampleVar + 5)
// The result of executing the expression tree:
// 6
' Add the following directive to your file:
' Imports System.Linq.Expressions  


' This block has a parameter expression
' that represents a variable within the block scope.
' It assigns a value to the variable,
' and then adds a constant to the assigned value. 

Dim varExpr As ParameterExpression = Expression.Variable(GetType(Integer), "sampleVar")
Dim blockExpr As BlockExpression = Expression.Block(
    New ParameterExpression() {varExpr},
    Expression.Assign(varExpr, Expression.Constant(1)),
    Expression.Add(varExpr, Expression.Constant(5))
)

' Print the expressions from the block expression.

Console.WriteLine("The expressions from the block expression:")
For Each expr In blockExpr.Expressions
    Console.WriteLine(expr.ToString())
Next

Console.WriteLine("The result of executing the expression tree:")

' The following statement first creates an expression tree,
' then compiles it, and then executes it.
Console.WriteLine(
    Expression.Lambda(Of Func(Of Integer))(blockExpr).Compile()())

' This code example produces the following output:
'
' The expressions from the block expression:
' (sampleVar = 1)
' (sampleVar + 5)
' The result of executing the expression tree:
' 6

Comentarios

Cuando se ejecuta la expresión de bloque, devuelve el valor de la última expresión del bloque.

Se aplica a

Block(Expression[])

Source:
BlockExpression.cs
Source:
BlockExpression.cs
Source:
BlockExpression.cs

Crea un objeto BlockExpression que contiene las expresiones dadas y que no tiene variables.

public:
 static System::Linq::Expressions::BlockExpression ^ Block(... cli::array <System::Linq::Expressions::Expression ^> ^ expressions);
public static System.Linq.Expressions.BlockExpression Block (params System.Linq.Expressions.Expression[] expressions);
static member Block : System.Linq.Expressions.Expression[] -> System.Linq.Expressions.BlockExpression
Public Shared Function Block (ParamArray expressions As Expression()) As BlockExpression

Parámetros

expressions
Expression[]

Expresiones del bloque.

Devoluciones

Objeto BlockExpression creado.

Ejemplos

En el ejemplo de código siguiente se muestra cómo crear una expresión de bloque. La expresión de bloque consta de dos MethodCallExpression objetos y un ConstantExpression objeto .

// Add the following directive to your file:
// using System.Linq.Expressions;

// The block expression allows for executing several expressions sequentually.
// When the block expression is executed,
// it returns the value of the last expression in the sequence.
BlockExpression blockExpr = Expression.Block(
    Expression.Call(
        null,
        typeof(Console).GetMethod("Write", new Type[] { typeof(String) }),
        Expression.Constant("Hello ")
       ),
    Expression.Call(
        null,
        typeof(Console).GetMethod("WriteLine", new Type[] { typeof(String) }),
        Expression.Constant("World!")
        ),
    Expression.Constant(42)
);

Console.WriteLine("The result of executing the expression tree:");
// The following statement first creates an expression tree,
// then compiles it, and then executes it.
var result = Expression.Lambda<Func<int>>(blockExpr).Compile()();

// Print out the expressions from the block expression.
Console.WriteLine("The expressions from the block expression:");
foreach (var expr in blockExpr.Expressions)
    Console.WriteLine(expr.ToString());

// Print out the result of the tree execution.
Console.WriteLine("The return value of the block expression:");
Console.WriteLine(result);

// This code example produces the following output:
//
// The result of executing the expression tree:
// Hello World!

// The expressions from the block expression:
// Write("Hello ")
// WriteLine("World!")
// 42

// The return value of the block expression:
// 42
' Add the following directive to your file:
' Imports System.Linq.Expressions

' The block expression enables you to execute several expressions sequentually.
' When the block expression is executed,
' it returns the value of the last expression in the sequence.
Dim blockExpr As BlockExpression = Expression.Block(
    Expression.Call(
        Nothing,
        GetType(Console).GetMethod("Write", New Type() {GetType(String)}),
        Expression.Constant("Hello ")
       ),
    Expression.Call(
        Nothing,
        GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}),
        Expression.Constant("World!")
        ),
    Expression.Constant(42)
)

Console.WriteLine("The result of executing the expression tree:")
' The following statement first creates an expression tree,
' then compiles it, and then executes it.           
Dim result = Expression.Lambda(Of Func(Of Integer))(blockExpr).Compile()()

' Print the expressions from the block expression.
Console.WriteLine("The expressions from the block expression:")
For Each expr In blockExpr.Expressions
    Console.WriteLine(expr.ToString())
Next

' Print the result of the tree execution.
Console.WriteLine("The return value of the block expression:")
Console.WriteLine(result)

' This code example produces the following output:
'
' The result of executing the expression tree:
' Hello World!

' The expressions from the block expression:
' Write("Hello ")
' WriteLine("World!")
' 42

' The return value of the block expression:
' 42

Comentarios

Cuando se ejecuta la expresión de bloque, devuelve el valor de la última expresión del bloque.

Se aplica a

Block(IEnumerable<Expression>)

Source:
BlockExpression.cs
Source:
BlockExpression.cs
Source:
BlockExpression.cs

Crea un objeto BlockExpression que contiene las expresiones dadas y que no tiene variables.

public:
 static System::Linq::Expressions::BlockExpression ^ Block(System::Collections::Generic::IEnumerable<System::Linq::Expressions::Expression ^> ^ expressions);
public static System.Linq.Expressions.BlockExpression Block (System.Collections.Generic.IEnumerable<System.Linq.Expressions.Expression> expressions);
static member Block : seq<System.Linq.Expressions.Expression> -> System.Linq.Expressions.BlockExpression
Public Shared Function Block (expressions As IEnumerable(Of Expression)) As BlockExpression

Parámetros

expressions
IEnumerable<Expression>

Expresiones del bloque.

Devoluciones

Objeto BlockExpression creado.

Comentarios

Cuando se ejecuta la expresión de bloque, devuelve el valor de la última expresión del bloque.

Se aplica a

Block(Type, IEnumerable<Expression>)

Source:
BlockExpression.cs
Source:
BlockExpression.cs
Source:
BlockExpression.cs

Crea un objeto BlockExpression que contiene las expresiones dadas, no tiene variables y tiene el tipo de resultado específico.

public:
 static System::Linq::Expressions::BlockExpression ^ Block(Type ^ type, System::Collections::Generic::IEnumerable<System::Linq::Expressions::Expression ^> ^ expressions);
public static System.Linq.Expressions.BlockExpression Block (Type type, System.Collections.Generic.IEnumerable<System.Linq.Expressions.Expression> expressions);
static member Block : Type * seq<System.Linq.Expressions.Expression> -> System.Linq.Expressions.BlockExpression
Public Shared Function Block (type As Type, expressions As IEnumerable(Of Expression)) As BlockExpression

Parámetros

type
Type

Tipo de resultado del bloque.

expressions
IEnumerable<Expression>

Expresiones del bloque.

Devoluciones

Objeto BlockExpression creado.

Se aplica a