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Hi!
There are two classes in my ATL dll. One called Apple, another called Banana.
Banana has a method to create and return an Apple.
In IDL it will be like
GetApple([out, retval] IApple** ret)
But i don't know how to write this method in the cpp of bananna.
I wrote:
{
CApple* p = new CApple();
*ret = p;
}
But the comiler said CApple is an abstract class and can't be created.
Do you have any experience in this thing?
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In fact, in my test project, Apple can be a class without any method or property.
I just don't know how to create a simple object with COM interface in another object's method inside COM DLL.
the idl of apple is
interface IApple : IDispatch{
};
and idl of banana is
interface IBanana : IDispatch{
[id(1), helpstring("GetApple")] HRESULT GetApple([out,retval] IApple** apple);
};
And i try to implement the GetApple as
#include "stdafx.h"
#include "Banana.h"
#include "Apple.h"
// CBanana
STDMETHODIMP CBanana::GetApple(IApple** apple)
{
*apple = new CApple();
return S_OK;
}
VC7 said the CApple is abstract class, so can't be created.
Any idea?
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Ah, I see now. See Q181265[^]
Basically, your CApple doesn't implement any of the IUnknown methods, that's why you can't create instances of it. You instead create instances of CComObject, which does implement IUnknown.
--Mike--
Ericahist | Homepage | RightClick-Encrypt | 1ClickPicGrabber
Latest art~!@#2rDFA#@(#*%$Rfa39f3fqwf--=
NO CARRIER
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Thanks! I wanna ask for a little more.
In Apple i try to hide a struct. It is not on the interface to the client. But the other class in the COM know it is there, and can access it.
in apple.h
struct Image
{
int num;
};
// CApple
class ATL_NO_VTABLE CApple :
public CComObjectRootEx<ccomsinglethreadmodel>,
public CComCoClass<capple, &clsid_apple="">,
public IDispatchImpl<iapple, &iid_iapple,="" &libid_fruitlib,="" *wmajor="*/" 1,="" *wminor="*/" 0="">
{
public:
Image img;
CApple()
{
}
The banana add a method
interface IBanana : IDispatch{
[id(1), helpstring("GetApple")] HRESULT GetApple([out,retval] IApple** apple);
[id(2), helpstring("QueryApple")] HRESULT QueryApple([in] IApple* apple, [out,retval] int * ret);
};
And in banana.cpp i try
STDMETHODIMP CBanana::GetApple(IApple** apple)
{
CApple* p = new CComObject<capple>();
p->img.num = 100;
*apple = p;
return S_OK;
}
STDMETHODIMP CBanana::QueryApple(IApple* apple, int* ret)
{
CApple* p = dynamic_cast<capple*>(apple);
*ret = p->img.num;
return S_OK;
}
But when i use this dll in c#, it always get a System.ExecutionEngineException.
the script is
FruitLib.Banana banana = new FruitLib.BananaClass();
FruitLib.Apple apple = banana.GetApple();
int n = banana.QueryApple(apple);
Any idea then?
Thanks!
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I've created a CRichEditCtrl dynamically ( run time ) in both Dialog based application and in Document based application.
In Dialog based application we could copy pase the text using Ctrl+C and Ctrl +V ..... it was success.... but in Document based ( SDI ) application its not possilbe copy paste the text.... anybody have any idea ? its urgent...!!
__________________
mrithulaghadaka saankethika vidhagdhan...!!
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Hello, Sir:
Now i have a problem. I am doing a project, and i used a temporary file in many objects. Because my project declare many object, and the objects uesed the temporay file .I want to delete in WM_CLOSE, but i am not sucessful. Can you help me? Thanks a lot.
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to continue:
I debug result is "The file was using in other process. I want to delete file after the program is end.
And i do that in OnClose()
CMyAppDlg::OnClose()
{
......;
::TerminateProcess(GetCurrentProcess(), 0);
DeleteFile(mytemporayfile);
}
Is it right?
Wish to get your replay! Thans a lot.
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Are you joking or what?:
So, you do:
....
::TerminateProcess(GetCurrentProcess(), 0);
DeleteFile(mytemporayfile);
...
Let me ask you: How you expect DeleteFile(mytemporayfile) directive to be executed if you just ::TerminateProcess(GetCurrentProcess(), 0) one line above???...
"...Ability to type is not enough to become a Programmer. Unless you type in VB. But then again you have to type really fast..."
Me
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Did u close the file handles properly ? otherwise u cant delete it.... pls get the last error valuse using GetLasError()...and pls check in error list ... if the sharing violation is the reason...u should close the hadles.........
tamaaaaaaaar...!! slathak..!!!
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How are you creating your temporary files? If you use tmpfile() to create the file, then it will be automatically deleted when it is closed, your program exits, or you call the _rmtmp() function.
Sonork 100.11743 Chicken Little
"You're obviously a superstar." - Christian Graus about me - 12 Feb '03
Within you lies the power for good - Use it!
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Hello, all:
Thanks your reply. I used CreateFile() to create my temporary file. Naybe because i don't shut up temporary file handle. I will continue to check it.
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Hello, Sir:
I have a matter about dll, static lib and dynamic lib for a long time. And i don't know what are they different. I want to master the knowledge. Can you help me? I wish to get your reply. Maybe you can give me some article or resource? Thanks,
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One difference between static and dynamic DLL binding is when the program gains access to the DLL. The concept is similar to compile-time processing using template and run-time processing using polymorphism.
Kuphryn
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Hello, sir:
Thanks you replay. Maybe i know it a little from you now. Can you tell me some article or resource about them. I want to master it entirety.
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There are many articles on DLL. Do a search at Google. Here is one tutorial.
http://www.flipcode.com/tutorials/tut_dll01.shtml
Kuphryn
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Thanks your reply. You are welcome.
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Hi,
I have a Console application were it parses the VBS file and Create objects for controls like Button,TextBox etc using COM.I want to implement Events for these objects using COM IConnectionPoint.Is it possible to invoke events for console app.?Pls help
I am really struggling.
Thynks in advance
Valar
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The events belong to the COM object itself, in that it fires them when if whats the client to know that the applicaple event has occured. You cannot force a client to just fire an event at will.
From VB to pick up events, you need to Dim with object using the WithEvents keyword, and then create a New instance somewhere else on the object. Then implements the call back event sub routines.
Giles
"Je pense, donc je mange." - Rene Descartes 1689 - Just before his mother put his tea on the table.
Shameless Plug - Distributed Database Transactions in .NET using COM+
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Actually what i want to know is,I create controls dynamically using COM in C++ console app by parsing the VBScript file.I want to fire events for these controls,Say when user clicks a Button the coressponding objects event has to be fired.Is this possible for console app using IConnectionPoint in COM..or any other way.
Thnks
Valar
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Hi,
I have a problem with WaitForSingleObject. my code are as follows
int RunExternalProES(LPTSTR ExecProc, int option)
{
STARTUPINFO si;
PROCESS_INFORMATION pi;
DWORD pProcessID;
ZeroMemory( &si, sizeof(si) );
si.cb = sizeof(si);
ZeroMemory( &pi, sizeof(pi) );
// Start the child process.
if( !CreateProcess(NULL, // No module name (use command line).
ExecProc, // Command line.
NULL, // Process handle not inheritable.
NULL, // Thread handle not inheritable.
TRUE, // Set handle inheritance to FALSE.
0, // No creation flags.
NULL, // Use parent's environment block.
NULL, // Use parent's starting directory.
&si, // Pointer to STARTUPINFO structure.
&pi ) // Pointer to PROCESS_INFORMATION structure.
)
{
return FALSE;
//( "CreateProcess failed." );
}
if (option == 1) {
WaitForSingleObject(pi.hProcess, INFINITE);
}
}
i found that sometime waitforsingleobject function will hang for some process.. is there any reson why this happens?
Thanks
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The process that spawns the new process has limited knowledge of what goes on afterward. If WaitForSingleObject() does not return for a long time then I suspect that the spawned process is not exiting.
Kuphryn
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kuphryn wrote:
I suspect that the spawned process is not exiting.
Yes, that would be my assumption as well
Ryan "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"
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HI.
Can someone tell what vectors are usauly used for and
what can be stored in them\Console app and WinApp.
I am a beginer can someone help me with this.
create vector of size 1000.
containing values 0.1,1.1.1.2,1.3,....,1.999;
display values in vector using the vector it self.
resize vector size 5.
empty out vector.
To pro's like you oaks this must be easy!
I did do but would like to see how someone else doe's it
just to make sure im wright.
maybe silly, but help me out pls.
lance
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use the template class std::vector<t>, you can store anything by choosing the right T. It behaves pretty much like a C array . In your case, code could look like
#include <vector>
typedef std::vector< float > vector_f;
vector_f v(1000);
for (size_t i = 0;i<v.size();++i)
v[i] = ???
v.resize(5);
v.clear();
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