Re: Singleton MFC Extension DLL
On Jan 7, 1:05 pm, MFDonadeli <mfdonad...@gmail.com> wrote:
On 7 jan, 16:01, Ajay Kalra <ajayka...@yahoo.com> wrote:
On Jan 7, 12:54 pm, MFDonadeli <mfdonad...@gmail.com> wrote:
Hi.
I declare a singleton on a MFC extension DLL, like this:
<pre>
//header file: SingleTon.h
class AFX_EXT_CLASS CMySingleton
{
public:
static CMySingleton* Instance()
{
if(!singleton)
singleton = new CMySingleton();
return singleton;
}
int a;
// Other non-static member functions
private:
CMySingleton() {}; =
// Private
constructor
CMySingleton(const CMySingleton&); =
// Prevent copy-
construction
CMySingleton& operator=(const CMySingleton&); // Pre=
vent
assignment
virtual ~CMySingleton() {};
static CMySingleton* singleton;
};
And in a cpp file I code the following line:
CMySingleton* CMySingleton::singleton = NULL;
</pre>
Code 2:
<pre>
CMySingleton *a;
a = CMySingleton::Instance();
</pre>
The problem is when I code "code 2" in a Regular Dll, all works fine,
but when I code "code 2" in another MFC extension DLL gives an error:
<pre>
unresolved external symbol "private: static class CMySingleton*
CMySingleton::singleton" (?singleton@CMySingleton@@0PAV1@A)
</pre>
Any idea?
Are you sure you are including the correct .lib file in MFC extesion
DLL where you code2 sits?
--
Ajay
Yes, via Project Dependencies on VS 2008...
As Joe already pointed out, it doesnt mean much in your case. All you
are ensuring is the build order as such. You need to somehow link to
the library you are trying to use.
How did this work for the Regular DLL for you? You would have the same
problem there as well.
--
Ajay
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