Compile Method
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Expression(Of TDelegate).Compile Method

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Compiles the lambda expression described by the expression tree into executable code and produces a delegate that represents the lambda expression.

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

'Declaration
Public Function Compile As TDelegate

Return Value

Type: TDelegate
A delegate of type TDelegate that represents the compiled lambda expression described by the Expression(Of TDelegate).

The Compile method produces a delegate of type TDelegate at runtime. When that delegate is executed, it has the behavior described by the semantics of the Expression(Of TDelegate).

The Compile method can be used to obtain the value of any expression tree. First, create a lambda expression that has the expression as its body by using the Lambda method. Then call Compile to obtain a delegate, and execute the delegate to obtain the value of the expression.

Version Notes

Windows Phone

 The Compile method is not supported in Windows Phone.

The following code example demonstrates how Compile is used to execute an expression tree.



      ' Lambda expression as data in the form of an expression tree.
      Dim expression As System.Linq.Expressions.Expression(Of Func(Of Integer, Boolean)) = Function(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.
      outputBlock.Text &= String.Format("deleg(4) = {0}", deleg(4)) & vbCrLf

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



Windows Phone OS

Supported in: 8.1, 8.0, 7.1

Windows Phone

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