This documentation is archived and is not being maintained.

VBFixedArrayAttribute Class

Indicates that an array in a structure or non-local variable should be treated as a fixed-length array.

Namespace:  Microsoft.VisualBasic
Assembly:  Microsoft.VisualBasic (in Microsoft.VisualBasic.dll)

[AttributeUsageAttribute(AttributeTargets.Field, Inherited = false, AllowMultiple = false)]
public sealed class VBFixedArrayAttribute : Attribute

For more detailed information, see the Visual Basic topic VBFixedArrayAttribute Class.

Visual Basic arrays are of variable length by default. This attribute is useful when using Visual Basic file input and output functions, such as FileGet and FilePut, and API calls that require fixed-length arrays.

Structure Book
    <VBFixedArray(4)> Public Chapter() As Integer 
End Structure 

Sub WriteData()
    Dim FileNum As Integer = FreeFile()
    Dim MyBook As Book
    ReDim MyBook.Chapter(4)
    ' Add code to populate the array.
    MyBook.Chapter(0) = 1
    MyBook.Chapter(1) = 2
    MyBook.Chapter(2) = 3
    MyBook.Chapter(3) = 4
    MyBook.Chapter(4) = 5
    ' Write the array to a file.
    FileOpen(FileNum, "C:\testfile", OpenMode.Binary, _
             OpenAccess.Write, OpenShare.Default)
    FilePut(FileNum, MyBook) ' Write data.
End Sub

The VBFixedArrayAttribute is informational and does not allocate any storage. The purpose of this attribute is to modify how arrays in structures and non-local variables are used by methods or API calls that recognize the VBFixedArrayAttribute. Keep in mind that this attribute does not convert a variable length array to a fixed array and that you must still allocate array storage using Dim or ReDim statements.


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0