将C＃中的对象数组返回给COM中的C

Question

我正在使用COM在C++和C＃之间进行通信。

我在C＃中的以下类

1. 电子邮件地址

   /// <summary> 
   /// Email Address 
   /// </summary> 
   public class EmailAddress 
   { 
       /// <summary> 
       /// SMTP Address 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)]   
       public string Address; 
   
       /// <summary> 
       /// Name 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string Name; 
   } 
   

2. 邮箱

   /// <summary> 
   /// MailBox Entity 
   /// </summary> 
   public struct MailBoxEntity 
   { 
       /// <summary> 
       /// SMTP Address 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string SMTPAddress; 
   
       /// <summary> 
       /// Mailbox Display Name 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string Name; 
   
       /// <summary> 
       /// Mailbox Server Name 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string sServerName; 
   } 
   

3. EmailEntity（尚未落实IEmailEntity将包含每个字段属性）

   /// <summary> 
   /// Class for Email Entity 
   /// </summary> 
   public class EmailEntity : IEmailEntity 
   { 
       /// <summary> 
       /// BccRecipients 
       /// </summary> 
       [MarshalAs(UnmanagedType.ByValArray)] 
       public EmailAddress[] BccRecipients; 
   
       /// <summary> 
       /// Body 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string Body; 
   
       /// <summary> 
       /// CcRecipients 
       /// </summary> 
       [MarshalAs(UnmanagedType.ByValArray)] 
       public EmailAddress[] CcRecipients; 
   
       /// <summary> 
       /// Culture 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string Culture; 
   
       /// <summary> 
       /// DateTimeCreated 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string DateTimeCreated; 
   
       /// <summary> 
       /// DateTimeReceived 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string DateTimeReceived; 
   
       /// <summary> 
       /// DateTimeSent 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string DateTimeSent; 
   
       /// <summary> 
       /// FromAddress 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string FromAddress; 
   
       /// <summary> 
       /// FromName 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string FromName; 
   
   
       /// <summary> 
       /// HasAttachments 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string HasAttachments; 
   
       /// <summary> 
       /// Id 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string Id; 
   
       /// <summary> 
       /// Importance 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string Importance; 
   
       /// <summary> 
       /// LastModifiedName 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string LastModifiedName; 
   
       /// <summary> 
       /// LastModifiedTime 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string LastModifiedTime; 
   
       /// <summary> 
       /// MimeContent 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string MimeContent; 
   
       /// <summary> 
       /// ParentFolderId 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string ParentFolderId; 
   
       /// <summary> 
       /// Original Mailbox 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public MailBoxEntity OriginalMailBox; 
   
   
       /// <summary> 
       /// ParentFolderName 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string ParentFolderName; 
   
       /// <summary> 
       /// ReceivedByAddress 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string ReceivedByAddress; 
   
       /// <summary> 
       /// ReceivedByName 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string ReceivedByName; 
   
       /// <summary> 
       /// Size 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string Size; 
   
       /// <summary> 
       /// Subject 
       /// </summary> 
       [MarshalAs(UnmanagedType.BStr)] 
       public string Subject; 
   
       /// <summary> 
       /// ToRecipients 
       /// </summary> 
       [MarshalAs(UnmanagedType.ByValArray)] 
       public EmailAddress[] ToRecipients; 
   
   } 
   

如何访问访问阵列EmailEnity的对象（在C++）从C＃ 函数返回并读取EmailEntity类的字段。请注意，EmailEntity类包含 EmailAddress []这样的成员，它本身就是一个对象数组。 我打算实现包含属性的接口IEmailEntity，以访问EmailEntity 的字段并使用它来访问C++中的字段。这是正确的方式吗？

如何在C++中访问诸如EmailAddress（EmailAddress [] ToRecipients）数组的复杂字段成员。

请建议。

感谢

Answer 1

你可以简化.NET这样的代码（删除应自动完成所有的MarshalAs）：

[ComVisible(true)] 
public class MyRootClass : IMyRootClass // some class to start with 
{ 
    public IEmailEntity[] GetEntities() 
    { 
     List<IEmailEntity> list = new List<IEmailEntity>(); 
     for(int i = 0; i < 10; i++) 
     { 
      EmailEntity entity = new EmailEntity(); 
      List<IEmailAddress> addresses = new List<IEmailAddress>(); 
      addresses.Add(new EmailAddress { Name = "Joe" + i }); 
      entity.BccRecipients = addresses.ToArray(); 
      entity.Body = "hello world " + i; 
      list.Add(entity); 
     } 
     return list.ToArray(); 
    } 
} 

[ComVisible(true)] 
public interface IMyRootClass 
{ 
    IEmailEntity[] GetEntities(); 
} 

public class EmailEntity : IEmailEntity 
{ 
    public IEmailAddress[] BccRecipients { get; set; } 
    public string Body { get; set; } 
} 

public class EmailAddress : IEmailAddress 
{ 
    public string Address { get; set; } 
    public string Name { get; set; } 
} 

[ComVisible(true)] 
public interface IEmailAddress 
{ 
    string Address { get; set; } 
    string Name { get; set; } 
} 

[ComVisible(true)] 
public interface IEmailEntity 
{ 
    IEmailAddress[] BccRecipients { get; set; } 
    string Body { get; set; } 
    // to be continued... 
} 

用C++使用它，你需要注册的DLL和构建一个.TLB（类型库文件）作为一个类似的答案了说明：Implement a C# DLL COM File In Unmanaged C++ Program

然后，您可以在C访问这些类++，就像这样：

#include "stdafx.h" 
#import "c:\MyPathToTheTlb\YourAssembly.tlb" // import the COM TLB 

using namespace YourAssembly; 

int _tmain(int argc, _TCHAR* argv[]) 
{ 
    CoInitialize(NULL); 
    IMyRootClassPtr ptr(__uuidof(MyRootClass)); 
    CComSafeArray<IUnknown*> entities = ptr->GetEntities(); // CComSafeArray needs atlsafe.h in the PCH 
    for(int i = entities.GetLowerBound(0); i <= entities.GetUpperBound(0); i++) 
    { 
    IEmailEntityPtr entity; 
    entities.GetAt(i).QueryInterface(&entity); 
    _bstr_t body = entity->Body; 
    printf("%S\n", body.GetBSTR()); 

    CComSafeArray<IUnknown*> recipients = entity->BccRecipients; 
    for(int j = recipients.GetLowerBound(0); j <= recipients.GetUpperBound(0); j++) 
    { 
     IEmailAddressPtr address; 
     recipients.GetAt(j).QueryInterface(&address); 
     _bstr_t name = address->Name; 
     printf(" %S\n", name.GetBSTR()); 
    } 
    } 
    CoUninitialize(); 
}