FieldOffsetAttribute Class
 
System_CAPS_noteNote

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Indicates the physical position of fields within the unmanaged representation of a class or structure.

Namespace:   System.Runtime.InteropServices
Assembly:  mscorlib (in mscorlib.dll)

SystemObject
   SystemAttribute
    System.Runtime.InteropServicesFieldOffsetAttribute

[AttributeUsageAttribute(AttributeTargets.Field, Inherited = false)]
[ComVisibleAttribute(true)]
public sealed class FieldOffsetAttribute : Attribute
[AttributeUsageAttribute(AttributeTargets::Field, Inherited = false)]
[ComVisibleAttribute(true)]
public ref class FieldOffsetAttribute sealed : Attribute
[<Sealed>]
[<AttributeUsageAttribute(AttributeTargets.Field, Inherited = false)>]
[<ComVisibleAttribute(true)>]
type FieldOffsetAttribute = 
    class
        inherit Attribute
    end
<AttributeUsageAttribute(AttributeTargets.Field, Inherited := False)>
<ComVisibleAttribute(True)>
Public NotInheritable Class FieldOffsetAttribute
	Inherits Attribute
NameDescription
System_CAPS_pubmethod FieldOffsetAttribute

Initializes a new instance of the FieldOffsetAttribute class with the offset in the structure to the beginning of the field.

NameDescription
System_CAPS_pubproperty

When implemented in a derived class, gets a unique identifier for this Attribute.(Inherited from Attribute.)

System_CAPS_pubproperty

Gets the offset from the beginning of the structure to the beginning of the field.

NameDescription
System_CAPS_pubmethod Equals

This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.)

System_CAPS_pubmethod GetHashCode

Returns the hash code for this instance.(Inherited from Attribute.)

System_CAPS_pubmethod GetType

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethod IsDefaultAttribute

When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.(Inherited from Attribute.)

System_CAPS_pubmethod Match

When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.)

System_CAPS_pubmethod ToString

Returns a string that represents the current object.(Inherited from Object.)

NameDescription
System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetIDsOfNames

Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.)

System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetTypeInfo

Retrieves the type information for an object, which can be used to get the type information for an interface.(Inherited from Attribute.)

System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetTypeInfoCount

Retrieves the number of type information interfaces that an object provides (either 0 or 1).(Inherited from Attribute.)

System_CAPS_pubinterface System_CAPS_privmethod _AttributeInvoke

Provides access to properties and methods exposed by an object.(Inherited from Attribute.)

You can apply this attribute to fields.

This attribute is used when System.Runtime.InteropServicesStructLayoutAttribute, with LayoutKindExplicit passed to its constructor, is applied to a class or structure to specify the offset of each non- static or constant member within the unmanaged representation of that class or structure.

The following example demonstrates how to apply the FieldOffsetAttribute to members of a class with an explicit layout.

[StructLayout(LayoutKind.Explicit)]
public class SYSTEM_INFO
{
[FieldOffset(0)] public ulong OemId;
[FieldOffset(8)] public ulong PageSize;
[FieldOffset(16)] public ulong ActiveProcessorMask;
[FieldOffset(24)] public ulong NumberOfProcessors;
[FieldOffset(32)] public ulong ProcessorType;
}
<StructLayout(LayoutKind.Explicit)> _
Public Class SYSTEM_INFO
    <FieldOffset(0)> Private OemId As System.UInt64
    <FieldOffset(8)> Private PageSize As System.UInt64
    <FieldOffset(16)> Private ActiveProcessorMask As System.UInt64
    <FieldOffset(24)> Private NumberOfProcessors As System.UInt64
    <FieldOffset(32)> Private ProcessorType As System.UInt64
End Class

[StructLayout(LayoutKind::Explicit)]
public ref class SYSTEM_INFO
{
public:

   [FieldOffset(0)]
   UInt64 OemId;

   [FieldOffset(8)]
   UInt64 PageSize;

   [FieldOffset(24)]
   UInt64 ActiveProcessorMask;

   [FieldOffset(32)]
   UInt64 NumberOfProcessors;

   [FieldOffset(40)]
   UInt64 ProcessorType;
};

For a larger example, see the System.Runtime.InteropServicesStructLayoutAttribute class.

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1

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

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