在Delphi中使用dispInterface没有classid

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问题描述

我已经导入一个类型库到Delphi XE2有很多dispinterfaces。大多数都有一个自动生成的coclass和相应的delphi T接口自动创建。

然而，我需要处理的一些dispinterfaces没有classid;我试过了我可以在网上找到的每个例子，以利用所讨论的dispinterface。接口如下：

  DIID_ITableListener：TGUID ='{83D42EA5-2C18-46EB- 823B-262D62DF8CF1}'; 
 ... 
 ITableListener = dispinterface; 
 ... 
 // ************************************* ******************************** // 
 // DispIntf：ITableListener 
 //标记：（4096）Dispatchable 
 // GUID：{83D42EA5-2C18-46EB-823B-262D62DF8CF1} 
 // ******************** ************************************************* / / 
 ITableListener = dispinterface 
 ['{83D42EA5-2C18-46EB-823B-262D62DF8CF1}'] 
程序添加（const rowID：WideString; const rowDataObj：IRow）; dispid 1610743809; 
 procedure Changed（const rowID：WideString; const rowDataObj：IRow）; dispid 1610743810; 
 procedure Deleted（const rowID：WideString; const rowDataObj：IRow）; dispid 1610743811; 
 procedure StatusChanged（status：TableStatus）; dispid 1610743812; 
 end;

以下是使用此dispinterinterface的类型库封装器中另一个接口的示例：

 过程subscribeUpdate（updateType：TableUpdateType; const listenerObj：ITableListener）;

下面是一个VB.NET示例，解释了如何使用dispinterface： / p>

 '如果要使用ITableListener接口的方法，必须创建
 'class +实现接口。例如，
 
 public class TableListener implements ITableListener {} 
 
'在您的应用程序中，您必须创建一个实现
'接口的类的实例。例如，
 
 TableListener tableListener = new TableListener（）;

没有ClassID如何在Delphi中实现？如何做实例化？我认为这将涉及到实现一个IDispatch接口后代，但是没有一个ClassID我找不到一种方法使这项工作。

 
 
 帮助！ / p> 
 
 
感谢。
解决方案
 a href =http://delphi-kb.blogspot.com/2010/12/what-is-dispinterface.html =nofollow>链接，并将您的界面替换为链接，并得出这样：
  ITableListener = dispinterface 
 ['{83D42EA5-2C18-46EB-823B- 262D62DF8CF1}'] 
程序添加（const rowID：WideString; const rowDataObj：IRow）; dispid 1610743809; 
 procedure Changed（const rowID：WideString; const rowDataObj：IRow）; dispid 1610743810; 
 procedure Deleted（const rowID：WideString; const rowDataObj：IRow）; dispid 1610743811; 
 procedure StatusChanged（status：TableStatus）; dispid 1610743812; 
 end; 
 
 IMyTableListener = interface（IDispatch）
 ['{INSERT ARBITRARY GUID HERE}'] 
程序添加（const rowID：WideString; const rowDataObj：IRow）; 
 procedure Changed（const rowID：WideString; const rowDataObj：IRow）; 
 procedure Deleted（const rowID：WideString; const rowDataObj：IRow）; 
 procedure StatusChanged（status：TableStatus）; 
 end; 
 
 
 TMyTableListener = class（TAutoObject，IMyTableListener）
 public 
程序添加（const rowID：WideString; const rowDataObj：IRow）; 
 procedure Changed（const rowID：WideString; const rowDataObj：IRow）; 
 procedure Deleted（const rowID：WideString; const rowDataObj：IRow）; 
 procedure StatusChanged（status：TableStatus）; 
 end; 
 
 {...} 
 var 
 Disp：IDispatch; 
 Dispint：ITableListener; 
 {...} 
 //这可能需要注册TMyTableListener ... 
 Disp：= CreateComObject（TMyTableListener）as IDispatch; 
 //或者，尝试这个（不确定语法）：
 Disp：= new TMyTableListener as IDispatch; 
 Disp.AddRef（）; //在C ++中，至少通过new（）创建类会导致一个0引用，所以你需要AddRef（），以便释放对象正确地销毁对象... 
 Dispint：= ITableListener ）; 
 subscribeUpdate（updateType，Dispint）; 
 {...} 
  
 
I've imported a type library into Delphi XE2 that has many dispinterfaces. Most of them have had an autocreated coclass and corresponding delphi T interface automatically created.
However, some of the dispinterfaces that I need to work with have no classid; I've tried every example that I could find on the net to utilize the dispinterface(s) in question. Here's what the interface looks like:
DIID_ITableListener: TGUID = '{83D42EA5-2C18-46EB-823B-262D62DF8CF1}';
... 
ITableListener = dispinterface;
...
// *********************************************************************//
// DispIntf:  ITableListener
// Flags:     (4096) Dispatchable
// GUID:      {83D42EA5-2C18-46EB-823B-262D62DF8CF1}
// *********************************************************************//
ITableListener = dispinterface
  ['{83D42EA5-2C18-46EB-823B-262D62DF8CF1}']
  procedure Added(const rowID: WideString; const rowDataObj: IRow); dispid 1610743809;
  procedure Changed(const rowID: WideString; const rowDataObj: IRow); dispid 1610743810;
  procedure Deleted(const rowID: WideString; const rowDataObj: IRow); dispid 1610743811;
  procedure StatusChanged(status: TableStatus); dispid 1610743812;
end;
Here's an example from another interface in the type library wrapper that uses this dispinterface:
procedure subscribeUpdate(updateType: TableUpdateType; const listenerObj: ITableListener);
Here's a VB.NET example that is provided that explains how the dispinterface is supposed to be used:
' If you want to use methods of the ITableListener interface, you must create a 
' class that+ implements the interface. For example,

public class TableListener implements ITableListener { }

' In your application you must create an instance of the class that implements  
' the interface. For example,

TableListener tableListener = new TableListener();
With no ClassID how do I implement this in Delphi? How do I do an instantiation? I thought it would have something to do with implementing an IDispatch interface descendant, but again without a ClassID I couldn't find a way to make this work.
Help!
Thanks.
 解决方案 
So I went through the sample provided in the link, and substituted your interfaces for the interfaces in the link, and came up with this:
ITableListener = dispinterface
  ['{83D42EA5-2C18-46EB-823B-262D62DF8CF1}']
  procedure Added(const rowID: WideString; const rowDataObj: IRow); dispid 1610743809;
  procedure Changed(const rowID: WideString; const rowDataObj: IRow); dispid 1610743810;
  procedure Deleted(const rowID: WideString; const rowDataObj: IRow); dispid 1610743811;
  procedure StatusChanged(status: TableStatus); dispid 1610743812;
end;

IMyTableListener = interface(IDispatch)
  ['{INSERT ARBITRARY GUID HERE}']
  procedure Added(const rowID: WideString; const rowDataObj: IRow); 
  procedure Changed(const rowID: WideString; const rowDataObj: IRow); 
  procedure Deleted(const rowID: WideString; const rowDataObj: IRow);
  procedure StatusChanged(status: TableStatus);
end;


TMyTableListener = class (TAutoObject, IMyTableListener)
public
  procedure Added(const rowID: WideString; const rowDataObj: IRow); 
  procedure Changed(const rowID: WideString; const rowDataObj: IRow); 
  procedure Deleted(const rowID: WideString; const rowDataObj: IRow);
  procedure StatusChanged(status: TableStatus);
end;

{ ... }
var
Disp: IDispatch;
Dispint: ITableListener;
{ ... }
// this may require that TMyTableListener is registered...
Disp := CreateComObject(TMyTableListener) as IDispatch;
// alternatively, try this (not sure about syntax):
Disp := new TMyTableListener as IDispatch;
Disp.AddRef();   // in C++, at least, creating the class via new() results in a 0 refcount, so you need to AddRef() so that releasing the object destroys the object appropriately...
Dispint := ITableListener(Disp);
subscribeUpdate(updateType, Dispint);
{ ... }
                        
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