Derived Class Function Pointer Error - C / C++ / MFC Discussion Boards

S p k 5215-Jan-10 0:50

5-Jan-10 0:50

Hi Experts,

Please help me with this issue.

How to hook the baloon tooltip window (which arrived when a device is connected to the pc showing "found new hardware") so that i can change the caption of it??
I have tried the hooking of WM_CREATE , but its not the right one..

Please help me.

Regards,
spk 521

c++

surekha.btech5-Jan-10 0:15

surekha.btech

5-Jan-10 0:15

can we write a program without main block in c++ please specify another way except using static block

Re: c++

«_Superman_»5-Jan-10 0:28

«_Superman_»

5-Jan-10 0:28

What is you're requirement/problem.

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Re: c++

CPallini5-Jan-10 0:28

CPallini

5-Jan-10 0:28

An application must contain the main function.
On the other hand, you may write a static library of functions (such libraries haven't the 'main block'), however that's a completely different thing...
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Re: c++

bilal haider5-Jan-10 0:56

bilal haider

5-Jan-10 0:56

Try this link. It will surely help you.
http://www.coolinterview.com/interview/16272/[^]

Re: c++

Richard MacCutchan5-Jan-10 1:15

Richard MacCutchan

5-Jan-10 1:15

surekha.btech wrote:
can we write a program without main block in c++

Certainly, you can write anything you like, but I doubt that it will be of any use. Wink | ;)

Re: c++

Hamid_RT5-Jan-10 3:17

Hamid_RT

5-Jan-10 3:17

Answer is a word: No.

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

Derived Class Function Pointer Error

J Forde5-Jan-10 0:11

J Forde

5-Jan-10 0:11

Hi
I'm getting the following error during compilation:

error C2440: '=' : cannot convert from 'void (__thiscall CCBEMFGUILayer::*)(const char *)' to 'void (__thiscall CCBEMFLayer::*)(const char *)'

on the line: pMFPostMessage = MFPostMessage; // see below

CCBEMFGUILayer::CCBEMFGUILayer()
{
sLayerSignature = "<SourceLayer Name=\"GUI\"";
pMFPostMessage = MFPostMessage;
}

CCBEMFGUILayer::~CCBEMFGUILayer()
{

}

string CCBEMFGUILayer::GetLayerSignature()
{
return sLayerSignature;
}

void CCBEMFGUILayer::MFPostMessage( const char *cGUIMessage )
{

string sRecvMessage;

sRecvMessage = (string)cGUIMessage;

return;
}

MFGUILayer inherits from MFLayer.

class CCBEMFLayer
{
public:
CCBEMFLayer();
virtual ~CCBEMFLayer();
virtual void MFPostMessage( const char * );
virtual string GetLayerSignature();
void (CCBEMFLayer::*pMFPostMessage)( const char * );

};

class CCBEMFGUILayer : public CCBEMFLayer
{
public:
CCBEMFGUILayer();
virtual ~CCBEMFGUILayer();
string GetLayerSignature();
void MFPostMessage( const char * );

protected:
string sLayerSignature;
};

MFGUILayer implements MFPostMessage and I want to store a pointer to this function so I can add it to a subscriber class and then call the appropriate function based on a message signature.

How do I cast this correctly (if at all)?

Any help or direction appreciated.

Jim

Re: Derived Class Function Pointer Error

CPallini5-Jan-10 0:24

CPallini

5-Jan-10 0:24

Why don't you use polymorphism for that?
Smile | :)

Re: Derived Class Function Pointer Error

J Forde5-Jan-10 4:39

J Forde

5-Jan-10 4:39

I thought I was doing that, however, turns out I was doing it in reverse - against the derived class - instead of the base class.

I've resolved the problem by declaring Base references and instantiating the derived class and casting where appropriate.

Thanks

help me please!

nenfa4-Jan-10 22:23

nenfa

4-Jan-10 22:23

how to mimic the operation of refurbishing desktop like the right-context-menu way?
in other words, you right-click on the desktop, there'll be the context menu which has the fresh button, you press fresh button to force refurbishing the desktop.
how can i mimic this operation through code.

Re: help me please!

KingsGambit4-Jan-10 23:35

KingsGambit

4-Jan-10 23:35

You can write shell extension for adding additional items to context menu. For details you can refer The Complete Idiot's Guide to Writing Shell Extensions - Part I[^]

Re: help me please!

nenfa4-Jan-10 23:48

nenfa

4-Jan-10 23:48

what i want is to reach the same effect by some simple codes but without any gui codes.

Re: help me please!

David Crow5-Jan-10 3:30

David Crow

5-Jan-10 3:30

It's not as simple as that. There's not a WM_REFRESH type of message that you can send to a window and have it refresh itself. Using Spy++, you can see what messages are sent to the desktop's list control and how it responds. In order to mimic this, I suspect a shell extension would be in order.

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

_variant_t conversion

MsmVc4-Jan-10 22:10

MsmVc

4-Jan-10 22:10

Hi All

Can i convert _variant_t to binary?Please give me advice.

Re: _variant_t conversion

CPallini4-Jan-10 22:19

CPallini

4-Jan-10 22:19

Data is already in binary form, you know. What kind of conversion do you really need? Could you make an example?
Smile | :)

Re: _variant_t conversion

MsmVc4-Jan-10 22:30

MsmVc

4-Jan-10 22:30

Thanks for reply
i am useing

ADODB::_RecordsetPtr rSet;

to get values from MS Access through this code.When Ms Access datatype is adLongVarBinary.

(j is indext number)
_variant_t vtValue;
vtValue =rSet->Fields->GetItem(j)->Value;

Then i am geting values like this

vtValue laues like this.
safearray = safearray of UI1 = [27609](21 ' ',28 ' ',45 '-',0,2 ' ',0,0,0,10 '
',0,15 ' ',0,20 ' ',0,30 ' ',0,255 'ÿ',255 'ÿ',255 'ÿ',255 'ÿ',87 'W',111 'o',114 'r',107 'k',115 's',104 'h',101 'e',101 'e',116 't',0,69 'E',120 'x',99 'c',101 'e',108 'l',46 '.',83 'S',10...

So how can i get this values in redable formate.

Re: _variant_t conversion

CPallini4-Jan-10 22:54

CPallini

4-Jan-10 22:54

What do you intend with 'readable format'? What's the array is supposed to contain?
Smile | :)

Re: _variant_t conversion

Madhu Nair4-Jan-10 23:33

Madhu Nair

4-Jan-10 23:33

I think you are trying to get values from a SAFEARRAY[^]

I suggest you to read this (How To Pass Arrays Between Visual Basic and C[^]) article, to get a starting point in SAFEARRAY handling.

Re: _variant_t conversion

KingsGambit4-Jan-10 22:19

KingsGambit

4-Jan-10 22:19

What is meant by converting _variant_t to binary?

Customize EditBox

kumar sanghvi4-Jan-10 21:55

kumar sanghvi

4-Jan-10 21:55

Hi,
Please suggest me any sample which is using Subclassing of CEdit class...

Re: Customize EditBox

Nelek4-Jan-10 22:07

Nelek

4-Jan-10 22:07

Here[^] you have a lot.

Regards.
--------
M.D.V. Wink | ;)

If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpfull answers is nice, but saying thanks can be even nicer.

Global variables

Pryabu4-Jan-10 19:45

Pryabu

4-Jan-10 19:45

Hi all,

How to prevent usage of global variables from other files.

thanks,

Re: Global variables

SandipG 4-Jan-10 20:07

SandipG

4-Jan-10 20:07

Check here[^]..
I hope it helps.

Regards,
Sandip.

Re: Global variables

KingsGambit4-Jan-10 20:08

KingsGambit

4-Jan-10 20:08

I think you can declare the global variables as static so that the access is restricted to specific translation units.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.