如何将.NET COM对象的实例从Delphi传递到另一个.NET COM对象?

在Delphi中,对象可能实现接口,但它们本身并不是接口对象。 要理解这种区别,您必须查看接口的原始实现 必须理解的是.NET的工作方式不同,所以 对象的.NET接口与所显示的ComVisible方面相同。

TYPE
  TMyObject = class(TInterfacedObject, IMyObject, IMyNewInterface)
  end;

您使用Delphi COM对象向导创建了一个新的COM对象。 这将实现该接口。 IMyNewInterface是在其他地方定义的辅助接口,您已经指出 对象实现。

 var
   I1: IMyObject;
   I2: IMyNewInterface;
   T: TMyObject;
 begin
   I1:=TMyObject.Create;
   I2:=TMyObject.Create;
   T:=TMyObject.Create;
 end;

您可以执行这些操作,因为TMyObject实现了这些接口。也, 因为这些是引用计数,所以当 因为使用的是对象引用而不是接口引用,所以必须释放

给定你发布的代码,如果你仔细观察,你会发现同样的情况。 在您的例子中,您的对象完全在.NET中实现,因此
您注意到在包装器上,没有第二个方法来传递实例 ,这是因为这个对象没有实现接口,

您可以通过执行以下操作来完成该任务:

如果您已经完成了一个tusermainance.Create(nil)调用并拥有该对象的一个实例,

 var
   UMDelphiWrapper: TUserMaintenance;
   UIDelphiWrapper: TUserInfo;
   UI: IUserInfo;
   UM: IUserMaintenance;


 begin
   //this part creates a Delphi OBJECT reference to the Implementation class -
   //this is NOT Reference counted, because it doesn't implement an interface.
   UIDelphiWrapper:=TUserInfo.Create(nil);
   try
     //this is the part where you acquire the interface of the object that actually
     //implementes this interface - e.g. your .NET class
     //not that this is the INTERFACE reference - which WILL be reference counted
     UI:=UIDelphiWrapper.DefaultInterface as IUserInfo;

     //UI.<Set some properties of your IUserInfo object>

     try
       //this part creates a Delphi OBJECT reference to the Implementation class -
       //this is NOT Reference counted, because it doesn't implement an interface.
       UMDelhpiWrapper:=TUserMaintenance.Create(nil);
       try
         //this is the part where you acquire the interface of the object that actually
         //implementes this interface - e.g. your .NET class
         //not that this is the INTERFACE reference - which WILL be reference counted
         UM:=UMdelphiWrapper.DefaultInterface as IUserMaintenance;
         try
           //Here, you have an interface type implemented by your .NET class that you are
           //sending to the implementation of your management object (Also a .NET class)
           UM.SendUser(UI);

           //do whatever else you need to do with your interface and user/management .NET object(s)
         finally
           //this IS a reference counted COM object - no "free" necessary 
           //this would naturally happen when the reference goes out of scope in the method
           //but for clairity sake is set to NIL to explicitly release your reference
           UM:=nil;
         end;

       finally
         //This is a delphi object that is NOT reference counted and must be released
        FreeAndNil(UMDelphiWrapper);     
       end;

     finally
       //this IS a reference counted COM object - no "free" necessary 
       //this would naturally happen when the reference goes out of scope in the method
       //but for clairity sake is set to NIL to explicitly release your reference
       UI:=nil; 
     end;
   Finally
     //This is a delphi object that is NOT reference counted and must be released
     FreeAndNIl(UIDelphiWrapper);
   end;

除了实际使用Delphi提供的包装器之外,只要知道正确的信息,就可以直接创建对.NET对象的引用。

var
  UI: IUserInfo;
  UM: IUserManager;

begin
  UI:=CreateOleObject('YourAssembly.YourImplementationClass') as IUserInfo;
  UI.SomeProperty:=SomeValue;
  UM:=CreateOleObject('YourAssembly.YourImplementationClass') as IUserManger;
  UM.SomeMetohd(UI);
end;

这段代码要干净得多——但是,您必须仍然拥有IUserInfo和IUserMaintenance的准确定义,并且知道对象的类友好名称,因为它们已经在COM中注册了。

您可以通过键入代码来完成此操作—这是当您从程序集导入COM公开的DLL时,类型导入函数应该为您完成的操作。我没有在您提供的代码中看到实际的实现,但是您仍然应该在头文件中找到这个信息。--如果没有,则说明没有导入正确的程序集,或者Delphi 7导入没有正常工作,或者需要刷新(例如,向.NET实现添加了新方法,但没有重新注册(使用COM)并重新导入新的程序集类型信息)。

type
  IUserInfo = interface
  ['22222222-2222-2222-2222-AAAAAAAAAAAA']
  //define your methods
  end;

希望我能正确理解你的问题。如果你想摆脱类型库中混乱的(和不必要的)用户信息,你不应该导出你的CoClass,只导出接口。

[ComVisible(true)]
[InterfaceType(ComInterfaceType.InterfaceIsDual)]
[Guid("22222222-2222-2222-2222-AAAAAAAAAAAA")]
public interface IUserInfo
{
}

[ClassInterface(ClassInterfaceType.None)]
[ComVisible(true)]
[Guid("22222222-2222-2222-2222-BBBBBBBBBBBB")]
public class UserInfo: IUserInfo
{
}

注意CoClass的第一个属性设置为 ClassInterfaceType.无 ,这样DotNet就不会向类型库显示CoClass本身。不过,您可以像往常一样在Delphi中实例化对象:

var
  pUserInfo: IUserInfo;
begin
  pUserInfo := CoUserInfo.Create;