Expression.NewArrayInit Method (Type, IEnumerable<Expression>)
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Creates a NewArrayExpression that represents creating a one-dimensional array and initializing it from a list of elements.
Assembly: System.Core (in System.Core.dll)
public static NewArrayExpression NewArrayInit( Type type, IEnumerable<Expression> initializers )
Parameters
- type
- Type: System.Type
A Type that represents the element type of the array.
- initializers
- Type: System.Collections.Generic.IEnumerable<Expression>
An IEnumerable<T> that contains Expression objects to use to populate the Expressions collection.
Return Value
Type: System.Linq.Expressions.NewArrayExpressionA NewArrayExpression that has the NodeType property equal to NewArrayInit and the Expressions property set to the specified value.
| Exception | Condition |
|---|---|
| ArgumentNullException | type or initializers is null. -or- An element of initializers is null. |
| InvalidOperationException | The Type property of an element of initializers represents a type that is not assignable to the type that type represents. |
The Type property of each element of initializers must represent a type that is assignable to the type represented by type, possibly after it is quoted.
Note: |
|---|
An element will be quoted only if type is Expression. Quoting means the element is wrapped in a Quote node. The resulting node is a UnaryExpression whose Operand property is the element of initializers. |
The Type property of the resulting NewArrayExpression represents an array type whose rank is 1 and whose element type is type.
The following example demonstrates how to use the NewArrayInit method to create an expression tree that represents creating a one-dimensional string array that is initialized with a list of string expressions.
List<System.Linq.Expressions.Expression> trees =
new List<System.Linq.Expressions.Expression>()
{ System.Linq.Expressions.Expression.Constant("oak"),
System.Linq.Expressions.Expression.Constant("fir"),
System.Linq.Expressions.Expression.Constant("spruce"),
System.Linq.Expressions.Expression.Constant("alder") };
// Create an expression tree that represents creating and
// initializing a one-dimensional array of type string.
System.Linq.Expressions.NewArrayExpression newArrayExpression =
System.Linq.Expressions.Expression.NewArrayInit(typeof(string), trees);
// Output the string representation of the Expression.
outputBlock.Text += newArrayExpression.ToString() + "\n";
// This code produces the following output:
//
// new [] {"oak", "fir", "spruce", "alder"}
Note: