StructLayoutAttribute StructLayoutAttribute StructLayoutAttribute StructLayoutAttribute Class

定義

讓您控制記憶體中類別或結構之資料欄位的實際配置。Lets you control the physical layout of the data fields of a class or structure in memory.

public ref class StructLayoutAttribute sealed : Attribute
[System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Struct, Inherited=false)]
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class StructLayoutAttribute : Attribute
type StructLayoutAttribute = class
    inherit Attribute
Public NotInheritable Class StructLayoutAttribute
Inherits Attribute
繼承
StructLayoutAttributeStructLayoutAttributeStructLayoutAttributeStructLayoutAttribute
屬性

範例

下列範例示範函式的 managed GetSystemTime宣告, 並使用LayoutKind.Explicit版面MySystemTime配置定義類別。The following example demonstrates a managed declaration of the GetSystemTime function and defines MySystemTime class with LayoutKind.Explicit layout. GetSystemTime取得系統時間並列印到主控台。GetSystemTime gets the system time and prints to the console.

using namespace System;
using namespace System::Runtime::InteropServices;


[StructLayout(LayoutKind::Explicit,Size=16,CharSet=CharSet::Ansi)]
value class MySystemTime
{
public:

   [FieldOffset(0)]
   short wYear;

   [FieldOffset(2)]
   short wMonth;

   [FieldOffset(4)]
   short wDayOfWeek;

   [FieldOffset(6)]
   short wDay;

   [FieldOffset(8)]
   short wHour;

   [FieldOffset(10)]
   short wMinute;

   [FieldOffset(12)]
   short wSecond;

   [FieldOffset(14)]
   short wMilliseconds;
};

ref class NativeMethods
{
public:

   [DllImport("kernel32.dll")]
   static void GetSystemTime( MySystemTime * st );
};

int main()
{
   try
   {
      MySystemTime sysTime;
      NativeMethods::GetSystemTime(  &sysTime );
      Console::WriteLine( "The System time is {0}/{1}/{2} {3}:{4}:{5}", sysTime.wDay, sysTime.wMonth, sysTime.wYear, sysTime.wHour, sysTime.wMinute, sysTime.wSecond );
   }
   catch ( TypeLoadException^ e ) 
   {
      Console::WriteLine( "TypeLoadException : {0}", e->Message );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "Exception : {0}", e->Message );
   }

}

using System;
using System.Runtime.InteropServices;

namespace InteropSample
{   

   [StructLayout(LayoutKind.Explicit, Size=16, CharSet=CharSet.Ansi)]
   public class MySystemTime 
   {
      [FieldOffset(0)]public ushort wYear; 
      [FieldOffset(2)]public ushort wMonth;
      [FieldOffset(4)]public ushort wDayOfWeek; 
      [FieldOffset(6)]public ushort wDay; 
      [FieldOffset(8)]public ushort wHour; 
      [FieldOffset(10)]public ushort wMinute; 
      [FieldOffset(12)]public ushort wSecond; 
      [FieldOffset(14)]public ushort wMilliseconds; 
   }

   internal static class NativeMethods
   {
      [DllImport("kernel32.dll")]
      internal static extern void GetSystemTime([MarshalAs(UnmanagedType.LPStruct)]MySystemTime st);
   };

   class TestApplication
   {      
      public static void Main()
      {
         try
         {
            MySystemTime sysTime = new MySystemTime();
            NativeMethods.GetSystemTime(sysTime);
            Console.WriteLine("The System time is {0}/{1}/{2} {3}:{4}:{5}", sysTime.wDay,
               sysTime.wMonth, sysTime.wYear, sysTime.wHour, sysTime.wMinute, sysTime.wSecond);            
         }         
         catch(TypeLoadException e)
         {
            Console.WriteLine("TypeLoadException : " + e.Message);
         }
         catch(Exception e)
         {
            Console.WriteLine("Exception : " + e.Message);
         }
      }
   }
}
Imports System.Runtime.InteropServices

Namespace InteropSample

   <StructLayout(LayoutKind.Explicit, Size:=16, CharSet:=CharSet.Ansi)> _
   Public Class MySystemTime
      <FieldOffset(0)> Public wYear As Short
      <FieldOffset(2)> Public wMonth As Short
      <FieldOffset(4)> Public wDayOfWeek As Short
      <FieldOffset(6)> Public wDay As Short
      <FieldOffset(8)> Public wHour As Short
      <FieldOffset(10)> Public wMinute As Short
      <FieldOffset(12)> Public wSecond As Short
      <FieldOffset(14)> Public wMilliseconds As Short
   End Class 'MySystemTime


   Friend Class NativeMethods

      <DllImport("kernel32.dll")> _
      Friend Shared Sub GetSystemTime(<MarshalAs(UnmanagedType.LPStruct)> ByVal st As MySystemTime)
      End Sub
   End Class 'NativeMethods

   Class TestApplication

      Public Shared Sub Main()
         Try
            Dim sysTime As New MySystemTime()
            NativeMethods.GetSystemTime(sysTime)
            Console.WriteLine("The System time is {0}/{1}/{2} {3}:{4}:{5}", sysTime.wDay, sysTime.wMonth, sysTime.wYear, sysTime.wHour, sysTime.wMinute, sysTime.wSecond)
         Catch e As TypeLoadException
            Console.WriteLine(("TypeLoadException : " + e.Message.ToString()))
         Catch e As Exception
            Console.WriteLine(("Exception : " + e.Message.ToString()))
         End Try
      End Sub 'Main
   End Class 'TestApplication
End Namespace 'InteropSample 

備註

您可以將此屬性套用至類別或結構。You can apply this attribute to classes or structures.

通用語言執行時間會控制 managed 記憶體中類別或結構之資料欄位的實體配置。The common language runtime controls the physical layout of the data fields of a class or structure in managed memory. 不過, 如果您想要將類型傳遞給非受控程式碼, 您可以StructLayoutAttribute使用屬性來控制類型的非受控版面配置。However, if you want to pass the type to unmanaged code, you can use the StructLayoutAttribute attribute to control the unmanaged layout of the type. 搭配使用屬性LayoutKind.Sequential , 強制依出現的順序來排列成員。Use the attribute with LayoutKind.Sequential to force the members to be laid out sequentially in the order they appear. 對於可型別的LayoutKind.Sequential類型, 會同時控制 managed 記憶體中的配置和非受控記憶體中的配置。For blittable types, LayoutKind.Sequential controls both the layout in managed memory and the layout in unmanaged memory. 對於非可型別的型別, 它會控制將類別或結構封送處理至非受控碼時的版面配置, 但不會控制 managed 記憶體中的配置。For non-blittable types, it controls the layout when the class or structure is marshaled to unmanaged code, but does not control the layout in managed memory. 搭配使用屬性LayoutKind.Explicit來控制每個資料成員的精確位置。Use the attribute with LayoutKind.Explicit to control the precise position of each data member. 這會同時影響可雙向和非可控制類型的受控和非管理配置。This affects both managed and unmanaged layout, for both blittable and non-blittable types. 使用LayoutKind.Explicit時, 您必須FieldOffsetAttribute使用屬性來指示類型中每個欄位的位置。Using LayoutKind.Explicit requires that you use the FieldOffsetAttribute attribute to indicate the position of each field within the type.

C#、Visual Basic 和C++編譯器預設會將Sequential版面配置值套用至結構。C#, Visual Basic, and C++ compilers apply the Sequential layout value to structures by default. 針對類別, 您必須明確地LayoutKind.Sequential套用此值。For classes, you must apply the LayoutKind.Sequential value explicitly. Tlbimp.exe (類型程式庫匯入工具)StructLayoutAttribute LayoutKind.Sequential會套用屬性, 它會在匯入類型程式庫時一律套用值。The Tlbimp.exe (Type Library Importer) also applies the StructLayoutAttribute attribute; it always applies the LayoutKind.Sequential value when it imports a type library.

建構函式

StructLayoutAttribute(Int16) StructLayoutAttribute(Int16) StructLayoutAttribute(Int16) StructLayoutAttribute(Int16)

使用指定的 StructLayoutAttribute 列舉型別 (Enumeration) 成員,初始化 LayoutKind 類別的新執行個體。Initializes a new instance of the StructLayoutAttribute class with the specified LayoutKind enumeration member.

StructLayoutAttribute(LayoutKind) StructLayoutAttribute(LayoutKind) StructLayoutAttribute(LayoutKind) StructLayoutAttribute(LayoutKind)

使用指定的 StructLayoutAttribute 列舉型別 (Enumeration) 成員,初始化 LayoutKind 類別的新執行個體。Initializes a new instance of the StructLayoutAttribute class with the specified LayoutKind enumeration member.

欄位

CharSet CharSet CharSet CharSet

表示根據預設,類別中的字串資料欄位應該封送處理為 LPWSTR,還是 LPSTRIndicates whether string data fields within the class should be marshaled as LPWSTR or LPSTR by default.

Pack Pack Pack Pack

控制記憶體中類別或結構之資料欄位的對齊。Controls the alignment of data fields of a class or structure in memory.

Size Size Size Size

指示結構或類別的絕對大小。Indicates the absolute size of the class or structure.

屬性

TypeId TypeId TypeId TypeId

在衍生類別中實作時,取得這個 Attribute 的唯一識別碼。When implemented in a derived class, gets a unique identifier for this Attribute.

(Inherited from Attribute)
Value Value Value Value

取得 LayoutKind 值,指定類別或結構的排列方式。Gets the LayoutKind value that specifies how the class or structure is arranged.

方法

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

傳回值,這個值指出此執行個體是否與指定的物件相等。Returns a value that indicates whether this instance is equal to a specified object.

(Inherited from Attribute)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

傳回這個執行個體的雜湊碼。Returns the hash code for this instance.

(Inherited from Attribute)
GetType() GetType() GetType() GetType()

取得目前執行個體的 TypeGets the Type of the current instance.

(Inherited from Object)
IsDefaultAttribute() IsDefaultAttribute() IsDefaultAttribute() IsDefaultAttribute()

在衍生類別中覆寫時,表示這個執行個體的值是衍生類別的預設值。When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.

(Inherited from Attribute)
Match(Object) Match(Object) Match(Object) Match(Object)

在衍生類別中覆寫時,會傳回值,表示這個執行個體是否等於指定物件。When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.

(Inherited from Attribute)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

建立目前 Object 的淺層複本 (Shallow Copy)。Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

傳回代表目前物件的字串。Returns a string that represents the current object.

(Inherited from Object)

明確介面實作

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr) _Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr) _Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr) _Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

將一組名稱對應至一組對應的分派識別項 (Dispatch Identifier)。Maps a set of names to a corresponding set of dispatch identifiers.

(Inherited from Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr) _Attribute.GetTypeInfo(UInt32, UInt32, IntPtr) _Attribute.GetTypeInfo(UInt32, UInt32, IntPtr) _Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

擷取物件的類型資訊,可以用來取得介面的類型資訊。Retrieves the type information for an object, which can be used to get the type information for an interface.

(Inherited from Attribute)
_Attribute.GetTypeInfoCount(UInt32) _Attribute.GetTypeInfoCount(UInt32) _Attribute.GetTypeInfoCount(UInt32) _Attribute.GetTypeInfoCount(UInt32)

擷取物件提供的類型資訊介面數目 (0 或 1)。Retrieves the number of type information interfaces that an object provides (either 0 or 1).

(Inherited from Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr) _Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr) _Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr) _Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

提供物件所公開的屬性和方法的存取權。Provides access to properties and methods exposed by an object.

(Inherited from Attribute)

適用於

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