Expression.TypeAs Method
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Creates a UnaryExpression that represents an explicit reference or boxing conversion where null is supplied if the conversion fails.
Assembly: System.Core (in System.Core.dll)
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.UnaryExpressionA UnaryExpression that has the NodeType property equal to TypeAs and the Operand and Type properties set to the specified values.
| Exception | Condition |
|---|---|
| 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)