StructLayoutAttribute StructLayoutAttribute StructLayoutAttribute StructLayoutAttribute Class

定义

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

继承

ObjectObjectObjectObject

AttributeAttributeAttributeAttribute

StructLayoutAttributeStructLayoutAttributeStructLayoutAttributeStructLayoutAttribute

属性

AttributeUsageAttribute ComVisibleAttribute

示例

下面的示例演示了托管的声明GetSystemTime函数，并定义MySystemTime类的LayoutKind.Explicit布局。The following example demonstrates a managed declaration of the GetSystemTime function and defines MySystemTime class with LayoutKind.Explicit layout. GetSystemTime 获取系统时间，并输出到控制台。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
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 

注解

可以将此特性应用于类或结构。You can apply this attribute to classes or structures.

公共语言运行时控制类或结构在托管内存中的数据字段的物理布局。The common language runtime controls the physical layout of the data fields of a class or structure in managed memory. 但是，如果你想要将类型传递到非托管代码，则可以使用StructLayoutAttribute属性来控制非托管类型的布局。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. 使用具有特性LayoutKind.Sequential以强制其出现顺序依次布局的成员。Use the attribute with LayoutKind.Sequential to force the members to be laid out sequentially in the order they appear. 对于可直接复制类型，LayoutKind.Sequential控制的两个托管内存中的布局和非托管内存中的布局。For blittable types, LayoutKind.Sequential controls both the layout in managed memory and the layout in unmanaged memory. 对于非 blittable 类型，它控制的布局时的类或结构封送到非托管代码，但不进行控制的托管内存中的布局。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. 使用具有特性LayoutKind.Explicit来控制每个数据成员的精确位置。Use the attribute with LayoutKind.Explicit to control the precise position of each data member. 这会影响托管和非托管布局，blittable 和非 blittable 类型。This affects both managed and unmanaged layout, for both blittable and non-blittable types. 使用LayoutKind.Explicit要求你使用FieldOffsetAttribute属性以指示每个字段在类型中的位置。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 + + 编译器应用Sequential结构默认情况下对布局值。C#, Visual Basic, and C++ compilers apply the Sequential layout value to structures by default. 对于类，则必须将应用LayoutKind.Sequential显式值。For classes, you must apply the LayoutKind.Sequential value explicitly. Tlbimp.exe （类型库导入程序）也适用StructLayoutAttribute特性; 它始终应用LayoutKind.Sequential值导入类型库时。The Tlbimp.exe (Type Library Importer) also applies the StructLayoutAttribute attribute; it always applies the LayoutKind.Sequential value when it imports a type library.

构造函数

字段

属性

方法

显式界面实现

适用于

另请参阅

• Tlbimp.exe（类型库导入程序）Tlbimp.exe (Type Library Importer)