Expression<TDelegate>.Compile 方法

public:
 TDelegate Compile();

public TDelegate Compile();

override this.Compile : unit -> 'Delegate

Public Function Compile () As TDelegate

返回

表示所Expression<TDelegate>描述的已编译 lambda 表达式的类型的TDelegate委托。

示例

下面的代码示例演示如何 Compile 执行表达式树。

// Lambda expression as data in the form of an expression tree.
System.Linq.Expressions.Expression<Func<int, bool>> expr = i => i < 5;
// Compile the expression tree into executable code.
Func<int, bool> deleg = expr.Compile();
// Invoke the method and print the output.
Console.WriteLine("deleg(4) = {0}", deleg(4));

/*  This code produces the following output:

    deleg(4) = True
*/

' Lambda expression as data in the form of an expression tree.
Dim expression As System.Linq.Expressions.Expression(Of Func(Of Integer, Boolean)) = Function(ByVal i) i < 5
' Compile the expression tree into executable code.
Dim deleg As Func(Of Integer, Boolean) = expression.Compile()
' Invoke the method and print the output.
MsgBox(String.Format("deleg(4) = {0}", deleg(4)))

' This code produces the following output:
'
' deleg(4) = True

注解

该方法 Compile 在运行时生成类型 TDelegate 委托。 执行该委托时，该委托的行为由该 Expression<TDelegate>委托的语义描述。

该方法 Compile 可用于获取任何表达式树的值。 首先，使用 Lambda 该方法创建一个 lambda 表达式，该表达式作为其主体。 然后调用 Compile 以获取委托，并执行委托以获取表达式的值。

public:
 TDelegate Compile(bool preferInterpretation);

public TDelegate Compile(bool preferInterpretation);

override this.Compile : bool -> 'Delegate

Public Function Compile (preferInterpretation As Boolean) As TDelegate

参数

返回

一个表示所描述的已编译 lambda 表达式的 Expression<TDelegate>委托。

public:
 TDelegate Compile(System::Runtime::CompilerServices::DebugInfoGenerator ^ debugInfoGenerator);

public TDelegate Compile(System.Runtime.CompilerServices.DebugInfoGenerator debugInfoGenerator);

override this.Compile : System.Runtime.CompilerServices.DebugInfoGenerator -> 'Delegate

Public Function Compile (debugInfoGenerator As DebugInfoGenerator) As TDelegate

参数

返回

包含 lambda 编译版本的委托。