Expression<TDelegate>.Compile Method
Microsoft Silverlight will reach end of support after October 2021. Learn more.
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)
Syntax
'Declaration
Public Function Compile As TDelegate
public TDelegate Compile()
Return Value
Type: TDelegate
A delegate of type TDelegate that represents the compiled lambda expression described by the Expression<TDelegate>.
Remarks
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<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.
Platform Notes
.png "Silverlight for Windows Phone"){kind=icon}
Silverlight for Windows Phone
The Compile method is not supported in Silverlight for Windows Phone.
Examples
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
// 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.
outputBlock.Text += String.Format("deleg(4) = {0}", deleg(4)) + "\n";
/* This code produces the following output:
deleg(4) = True
*/
Version Information
Silverlight
Supported in: 5, 4, 3
Silverlight for Windows Phone
Supported in: Windows Phone OS 7.1
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.