C ++和Delphi之间的通信 [英] Communication between C++ and Delphi
问题描述
让我试着在这里解释一下我的问题。
我有一个DLL，它是用C ++编写的。它监视所有打印对象的传入打印作业（通过线程），然后从打印详细信息中获取一些信息。到这里可以。现在我必须将此信息发送给加载此C ++ DLL的delphi项目。
我真的很无能为力如何实现这种沟通
让c ++代码具有以下功能：
初始化或开始监控打印对象（启动线程）
如果有任何打印作业，提取asome信息
现在我必须发送将此信息提供给等待它的Delphhi代码。
让Delphi代码如下：
[DELPHI CODE]
加载DLL;
等待消息
卸载DLL
可以任何一个给我任何整体的想法。无需告诉我代码，但需要一些机制。
更新：
使用共享内存是解决方案吗？
谢谢。
Hi, Let me try to explain my problem here.
I have a DLL, it is written in C++. It monitors all print objects for incoming print jobs (Through a Thread)and then fetch some information from print details. Upto here it is OK. Now I have to send this information to delphi project who loaded this C++ DLL.
I am really clueless how can I make this communication happen
Let the c++ code has following functionality:
Initialize or start monitoring print objects (starts thread)
if any print job comes, asome information is fetched
Now I have to send back this info to that Delphhi code who is waiting for it.
Let the Delphi code is like below:
[DELPHI CODE]
Load DLL;
Wait for message
Unload DLL
Can any one give me any overall all idea. No need to tell me the code but some mechanism is needed.
update:
Is use of share memory is that solution?
Thanks.
推荐答案
如果您有两个部分的源代码，C ++和Delphi并且您使用C ++ Builder / Rad Studio构建了这两个部分，那么您可以从Delphi调用C ++代码，反之亦然。
在这种情况下，你可以通过回调做你想做的事。您将Delphi函数的地址作为函数指针参数传递给C ++。然后在C ++有要发回的消息时使用该指针调用Delphi函数。
这可能听起来很复杂，但它比共享内存简单得多。
您的C ++ Builder / Rad Studio应该有调用另一种代码的样本，在C ++函数指针中添加一些谷歌研究，你应该能够使它工作。
If you have the source to both parts, C++ and Delphi and you build both with C++ Builder/Rad Studio then you can call the C++ code from the Delphi and the other way around too.
In that case you could do what you want with a callback. You pass the address of a Delphi function into the C++ as a function pointer parameter. Then call the Delphi function using that pointer when the C++ has a message to send back.
It may sound complicated but it''s a lot simpler than shared memory.
Your C++ Builder/Rad Studio should have samples for calling one kind of code from the other, add a little google research into C++ function pointers and you should be able to make it work.
假设你使用的是Visual C ++，你可以使用COM，这是一个非常好的教程：为VS2012编写简单COM / ATL DLL的初学者教程 [ ^ ]
Delphi适用于COM，因此访问COM对象应该非常简单。
最好的问候
Espen Harlinn
Assuming you''re using Visual C++, you could use COM, here is a pretty nice tutorial: A Beginner Tutorial for Writing Simple COM/ATL DLL For VS2012[^]
Delphi works pretty well with COM, so accessing the COM object should be quite easy.
Best regards
Espen Harlinn
C++ DLL: "MyDll.dll"
/////////////////////////////////////////////////////
typedef HRESULT (CALLBACK * CALLBACKPROC)(DWORD wEvent,LONG_PTR arg,PVOID pParam);
/////////////////////////////////////////////////////
CALLBACKPROC g_pCallback = NULL;
LPVOID g_pCallbackParam = NULL;
/////////////////////////////////////////////////////
EXTERN_C VOID __declspec(dllexport) WINAPIV SetCallback(CALLBACKPROC _proc,LPVOID pParam)
{
g_pCallback = _proc;
g_pCallbackParam = pParam;
}
/////////////////////////////////////////////////////
#define SOMEDLLMETHOD_EVENT_ID 0x01
/////////////////////////////////////////////////////
EXTERN_C VOID __declspec(dllexport) WINAPIV SomeDllMethod()
{
if (g_pCallback) g_pCallback(SOMEDLLMETHOD_EVENT_ID,(LONG_PTR)"some argument",g_pCallbackParam);
}
/////////////////////////////////////////////////////
// Delphi wrapper with dynamic DLL linkage:
/////////////////////////////////////////////////////
type
TDllWrapper = class
protected
FOnDllEvent: TNotifyEvent;
m_hDll: HMODULE;
protected
function OnCallbackEvent(wEvent:DWORD;arg:Pointer):HRESULT; virtual;
public
procedure CallSomeDllMethod();
public
constructor Create;
destructor Destroy;
published
property OnDllEvent: TNotifyEvent read FOnDllEvent write FOnDllEvent;
end;
type
TCALLBACKPROC = function(wEvent:DWORD;arg:Pointer;pParam:Pointer):HRESULT stdcall;
type
TSetCallbackFunc = procedure(_proc:TCALLBACKPROC;pParam:Pointer) cdecl;
const SOMEDLLMETHOD_EVENT_ID =
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