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Hello Friends,
I have a question .
It is possible to call a second dll from the First Dll in VC++ application.
Case 1:
For example I a have dll called Sample A dll , then I have a second dll Sample B dll . It is possible to call Sample B dll from Sample A dll? All dlls are created using win32 dynamic DLL in VC++ platform.
Can any one tell me what are the merits and demerits of such a method ?
Case 2:
To avoid such a situation is it possible to include the functionality the second dll in the first dll, so that calling a second dll from the first dll can be eliminated completely.
Can any one tell me which of two Cases ie Case 1 and Case 2 is easy and more Reliable.
-- modified at 2:22 Wednesday 22nd February, 2006
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you make the dll or its already there? if you are making it , then why not include the "second" dll's functionality in the "first" ? or if you want to separate the functionalities you can still do. its always possible. just like you call the "first" dll from your application, you can do it in the same way to call the "second" dll from the "first".. get me ?
VuNic
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Hey all:
I wanted to have a basic service running on Windows XP. So, I went into Visual Studio (2005) and opened up the basic Windows Service template. I compiled, no problems, and went to the debug directory of my compile. As the template indicated, I typed myprojectname.exe /install . The install seemed to run fine, but, myprojectname did not appear as a new service. Can anyone explain this?
Thanks a lot!
Jim
Did I post well? Rate it! Did I post badly? Rate that too!
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Hell0 !
Did you check your tasklist (Taskmanager)? Is your service EXE runnig, is shown over there..?
-Malli...!
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No, the tasklist does not list the program under it. I am definitely installing the programming as a service (or trying) as it does the whole, commit phase sucessful, etc.
Other ideas?
Did I post well? Rate it! Did I post badly? Rate that too!
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The MFC appwizard handles function pointer arrays very differently than the console appwizard. There are a variety of ways to establish a function pointer array with a console program. My favorite is:
void show1();
void show2();
void show3();
void (*pfun[3])() = { show1, show2, show3 };
This works great for a console program, but an MFC program objects saying you cannot create an array of functions, and then just to be frustrating, the error explanation says you can
create an array of pointers to functions.
I was able to create a function pointer array using typedef:
typedef void FOO();
FOO* pfun[3];
The MFC compiler compiles the above without errors, but it will not allow me to initialize the array. I get compiler errors from:
FOO* pfun[3] = { show1, show2, show3 };
and:
pfun[0] = show1;
pfun[1] = show2;
pfun[2] = show3;
and even:
pfun[0] = &show1;
pfun[1] = &show2;
pfun[2] = &show3;
How do I initialize a function pointer array that ?
CastleIsle
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What compiler errors do you get, exactly?
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Console and MFC application are the same for these kind of things. This is just standard C++ and this won't change if you are doing a console app or a MFC app.
Post the exact error message and the complete definition of the different functions and maybe we can help. Maybe you are trying to use class member functions which doesn't have the same prototype.
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The following code gives me a compile error C2440
'=' : cannot convert from 'void (__cdecl MyClass::*)(void)' to 'void (__cdecl *)(void)'
Header:
class MyClass
{
MyClass();
typedef void FOO();
FOO Show;
FOO *pfun[2];
}
Source:
MyClass::MyClass()
{
pfun[0] = Show;
}
In the error message, the only difference between the two types is the scope resolution operator.
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Member function pointers are a bit tricky.
The class declaration should look like this:
class CMyClass
{
public:
void Assign()
{
m_FuncArray[0] = Fn1;
m_FuncArray[1] = Fn2;
m_FuncArray[2] = Fn3;
}
void Use()
{
(this->*(m_FuncArray[0]))();
}
protected:
typedef void (CMyClass::*MyFuncPtr_t)();
MyFuncPtr_t m_FuncArray[3];
void Fn1() { TRACE( "CMyClass::Fn1 called.\n" ); }
void Fn2() { TRACE( "CMyClass::Fn2 called.\n" ); }
void Fn3() { TRACE( "CMyClass::Fn3 called.\n" ); }
};
It's supposed to be hard, otherwise anybody could do it!
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Wow, this looks really promising. I am sorry I did not see your post until now. I have an out of town job commitment that will not permit me to try this out until Friday. Thank you, Roger. I can hardly wait to try it.
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CastleIsle wrote: void show1();
void show2();
void show3();
void (*pfun[3])() = { show1, show2, show3 };
There is nothing wrong with your declaration, but using a typedef for the function pointer type would make things more clear, e.g.
typedef (*MyFunctionPointer_t)();
MyFunctionPointer_t MyFunctionPointerArray[3] = { show1, show2, show3 };
There is no difference between a console app and an MFC app, it's still C/C++ synthax.
Hope this helps
--
Roger
It's supposed to be hard, otherwise anybody could do it!
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Thank you everyone for your suggestions. This is still unresolved.
MFC app compiler should have the same c/c++ rules as the console app compiler, but it doesn't. Here is another example:
int TestArray[] = {3,4,5}; // MFC will only accept this within
// a function. MFC rejects this
// statement in a header file.
// Console compiles the line
// in either location.
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CastleIsle wrote: MFC app compiler should have the same c/c++ rules as the console app compiler, but it doesn't.
Oh, yes it does. 
This is not dependant on whether you are building a console app or an MFC app.
Since you are DEFINING the variable in a header file you will get errors if that header file is included in more than one source file. The linker will complain about multiple definitions.
You can have as many DECLARATIONS as you want, but you can only DEFINE a variable in one place.
Probably in your console project you have only one definition since the header file is included in one source file only, but several in your MFC app since the AppWiz includes each header file in more than one source file by default.
Tip of the day: never define variables in header files.;)
If you write your statement at the top of one single source file then the variable will be defined only once. Declare it as extern in the header file to be able to access in from other source files.
If this doesn't clear things up for you, post again and describe how and where you declare your variable and why.
--
Roger
It's supposed to be hard, otherwise anybody could do it!
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All my header files have the standard
#if !defined(gobbledygook)
#define gobbledygook
// definitions here
#endif
... supplied by Visual C++ wizardry to prevent double definitions. Anyway, I have also tried defining the function pointer array in the source file and the MFC compiler still objects to initialization. I wish you were right.
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CastleIsle wrote: #if !defined(gobbledygook)
#define gobbledygook
// definitions here
#endif
When the next source file in the build process is built, the definition above is undefined. If you declare a class and plan to use it in more than one file, you have to include the header file with the class declaration in every file that uses the class in question, otherwise the class will be undefined.
Each source file is compiled separately and for each source file an object file (.obj) will be generated. The linker will link the object files together and build the executable. There is no mysterious way for the compiler to guess what was declared/defined when the last file was compiled.
(Sorry, but I consider this basic C/C++ knowledge...)
CastleIsle wrote: I have also tried defining the function pointer array in the source file and the MFC compiler still objects to initialization.
Yep, but that's because you're doing it wrong. See my previous post on your reply to Cedric about how to deal with arrays of function pointers to member functions.
CastleIsle wrote: I wish you were right.
I am right. 
![Rose | [Rose]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/rose.gif)
--
Roger
It's supposed to be hard, otherwise anybody could do it!
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i'm using this code snippet to create a temp file name :
<br />
CString CUtil::CreateTempFileName( void ) <br />
{<br />
CString cs = "";<br />
TCHAR szTempName[_MAX_PATH];<br />
TCHAR szPath[_MAX_PATH];<br />
if(GetTempPath(sizeof(szPath), szPath) != 0)<br />
{<br />
if(GetTempFileName(szPath, _T("csc"), 0, szTempName) != 0)<br />
{<br />
cs = szTempName;<br />
}<br />
}<br />
return( cs );<br />
}<br />
Its results in something like :
c:\DOKUME~1\USERKE~1\LOKALE~1\Temp\csc14.tmp
Anybody with an idea how to get the (real) long file name instead of this old 8.3 notation ?
Thank's for any hint !
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Have a look at the GetLongPathName function.
Steve
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Is working ... thank's a lot
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Dear All
I have tried to enter Arabic/Urdu strings in a Visual C++ project, in the VS IDE they look just find, but when I compile and run the application they just show up as ? marks like ????.
Any Ideas?
- A programmer's national anthem; "AAAAAHHHHH!!!!"
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You need to build your application Unicode aware for displaying such characters you told.
Regards,
Rajesh R. Subramanian
You have an apple and me too. We exchange those and We have an apple each.
You have an idea and me too. We exchange those and We have two ideas each.
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Try for UNICODE compatible functins in your project. make use of _T() like functions rather that normal ASCII Functions.
-Malli...!
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In the project settings, I have specified "Unicode Character Set".
and I only entered a menu option in Urdu, it was displaying it alright inside the IDE, but when I ran it, they were showing as ????. Do I need to used _T() for Menu Resource, if yes, where do I do that?
- A programmer's national anthem; "AAAAAHHHHH!!!!"
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See the following link and unires sample. Basically you need to save the file in Unicode and comment out the #pragma codepage directive. You will not be able to edit the file with Visual Studio's resource editor. You need to edit it with a Unicode enabled source editor.
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hello....
i have to read a file that has hex values.....i read them as string initially,i would want to know if there is already a function to convert this string(of hex) directly to int?....like we have for converting string(of int) to integer using atoi() fnction....?
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