Expression.NewArrayInit Method (Type, array<Expression[])
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Creates a NewArrayExpression that represents creating a one-dimensional array and initializing it from a list of elements.
Namespace: System.Linq.Expressions
Assembly: System.Core (in System.Core.dll)
Syntax
'Declaration
Public Shared Function NewArrayInit ( _
type As Type, _
ParamArray initializers As Expression() _
) As NewArrayExpression
public static NewArrayExpression NewArrayInit(
Type type,
params Expression[] initializers
)
Parameters
- type
Type: System.Type
A Type that represents the element type of the array.
- initializers
Type: array<System.Linq.Expressions.Expression[]
An array of Expression objects to use to populate the Expressions collection.
Return Value
Type: System.Linq.Expressions.NewArrayExpression
A NewArrayExpression that has the NodeType property equal to NewArrayInit and the Expressions property set to the specified value.
Exceptions
| Exception | Condition |
|---|---|
| ArgumentNullException | type or initializers is nulla null reference (Nothing in Visual Basic). -or- An element of initializers is nulla null reference (Nothing in Visual Basic). |
| InvalidOperationException | The Type property of an element of initializers represents a type that is not assignable to the type type. |
Remarks
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.
.gif "Note") 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.
Examples
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.
Dim trees As New System.Collections.Generic.List(Of System.Linq.Expressions.Expression) _
(New 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.
Dim newArrayExpression As System.Linq.Expressions.NewArrayExpression = _
System.Linq.Expressions.Expression.NewArrayInit(Type.GetType("System.String"), trees)
' Output the string representation of the Expression.
outputBlock.Text &= newArrayExpression.ToString() & vbCrLf
' This code produces the following output:
'
' new [] {"oak", "fir", "spruce", "alder"}
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"}
Version Information
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
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.