Export (0) Print
Expand All
Expand Minimize

Expression.TypeAs Method

Creates a UnaryExpression that represents an explicit reference or boxing conversion where null is supplied if the conversion fails.

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

public static UnaryExpression TypeAs(
	Expression expression,
	Type type
)

Parameters

expression
Type: System.Linq.Expressions.Expression
An Expression to set the Operand property equal to.
type
Type: System.Type
A Type to set the Type property equal to.

Return Value

Type: System.Linq.Expressions.UnaryExpression
A UnaryExpression that has the NodeType property equal to TypeAs and the Operand and Type properties set to the specified values.

ExceptionCondition
ArgumentNullException

expression or type is null.

The Method property of the resulting UnaryExpression is null. The IsLifted and IsLiftedToNull properties are both false.

The following example demonstrates how to use the TypeAs(Expression, Type) method to create a UnaryExpression that represents the reference conversion of a non-nullable integer expression to the nullable integer type.


// Create a UnaryExpression that represents a
// conversion of an int to an int?.
System.Linq.Expressions.UnaryExpression typeAsExpression =
    System.Linq.Expressions.Expression.TypeAs(
        System.Linq.Expressions.Expression.Constant(34, typeof(int)),
        typeof(int?));

outputBlock.Text += typeAsExpression.ToString() + "\n";

// This code produces the following output:
//
// (34 As Nullable`1)


Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Community Additions

ADD
Show:
© 2014 Microsoft