C / C++ / MFC

Re: Environment Variables

16-Oct-08 10:27

What compiler are you using?

This line alone won't compile:

LPDWORD pKeyType = REG_SZ; <-- error C2440: 'initializing' : cannot convert from 'int' to 'LPDWORD'

There's several problems

HKEY hMyKey;
long lResult;
LPDWORD pKeyType = REG_SZ;   <code><-- wrong data type - should be a DWORD
It's also an OUT variable (if used correctly) so initializing it is pointless</code>
LPDWORD pKeySize = 0;  <code><-- wrong data type</code>
char* strKeyName = "SSSRights";
char* strKeyVal = "\0";   <code><-- You need to actually allocate space for the returned characters  
Had the query actually succeeded, it most likely would have crashed 
trying to write data to a const character array of length 1.</code>

jpyp wrote:
Why do I need the first call to RegQueryValueEx? What does it do?

It sets KeySize to the number of BYTES required to store the returned string.
I use that value to know how big the buffer needs to be, which I allocate on
the next line.

You could have just allocated an arbitrary number of bytes, but
you'd get a truncated string if the registry entry was longer than your buffer.
The function is capable of returning the necessary buffer size, so that's the
proper way to do it.

jpyp wrote:
Why does the first call fail when I provide a buffer instead of NULL?

Your incorrect use of LPDWORD pKeySize = 0; effectively reults in passing a NULL pointer as the
lpcbData parameter in the RegQueryValueEx() call. That is not allowed - the function
needs to know how big of a buffer it has to return data in and also needs to be able
to set the actual number of bytes placed in the buffer.

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

modified on Thursday, October 16, 2008 4:35 PM

jpyp16-Oct-08 10:52

jpyp

16-Oct-08 10:52

I use Studio 6.0 and you are right it does not compile. I had taken out the initialization before in my code but forgot to take it out in my first post here.

I understand now why it wasn't working initially. The size of the buffer must be the same as the value in the last field. I was providing a value of 0 for KeySize because I thought it was a output value only. So only one call is necessary but it is certainly safer to do it your way to get the actual size of the value.

As for the wrong data types, I took those directly from the MSDN library help page. Their data type are LPDWORD for the key type and key size fields.

Thanks a lot for your help!

jpyp

Re: Environment Variables

Mark Salsbery16-Oct-08 11:03

16-Oct-08 11:03

jpyp wrote:
As for the wrong data types, I took those directly from the MSDN library help page. Their data type are LPDWORD for the key type and key size fields.

Are you talking about the parameter types for the RegQueryValueEx() function?

If so, then yes, that is the type of variable that needs to be passed...
that doesn't necessarily mean your variables are supposed to be that type.

For example, a parameter with type LPDWORD - if you read the docs for
that parameter, you'll see wording like "A pointer to a variable that receives..."
or "A pointer to a variable that specifies...". That is NOT what you were passing Smile | :)

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Weird error...

Megidolaon15-Oct-08 11:08

Megidolaon

15-Oct-08 11:08

I just tried to use a map and since I don't know how to access an element yet, I thought I'd just set a breakpoint once it's filled and check the contents myself (I randomly assumed that like in VS C# you can see all members of an object at runtime if you set a breakpoint).

However, it doesn't even get there and I get a weird error instead:

Debugging Information for 'Graphics Test.exe' cannot be found or does not match. Symbols not loaded.<br />
<br />
Do you want to continue debugging?

What happened?

Thanks

led mike15-Oct-08 11:32

led mike

15-Oct-08 11:32

Megidolaon wrote:
What happened?

You reached what is sometimes referred to as "the limit of your knowledge". Wink | ;)

led mike

Megidolaon15-Oct-08 11:37

Megidolaon

15-Oct-08 11:37

Yes...which is exactly why I'm asking what happened... D'Oh! | :doh:

CPallini15-Oct-08 21:51

CPallini

15-Oct-08 21:51

5.

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]

automatically click a button in another application

David Crow15-Oct-08 17:29

David Crow

15-Oct-08 17:29

Megidolaon wrote:
What happened?

Does this help?

"Love people and use things, not love things and use people." - Unknown

"The brick walls are there for a reason...to stop the people who don't want it badly enough." - Randy Pausch

Russell^'15-Oct-08 9:34

Russell^'

15-Oct-08 9:34

I need to write a simple software to do something very repetitive...the perfect job for a program (not for humans)! Smile | :)

This software has simply to do many (many many many) times:
1) press a button on another application (no source code available, only the exe is provided) [ x and y coordinates of the point to click are known]
2) catch an area of the screen to save it as an image [the rect to catch is known]

About point 2 I found, here on codeproject, some examples on how do the catch of the screen and the file export. But I've absolutely any idea about point 1). This because it is something completely different from the usual software I develope.

Can you point me in the right direction? any suggestion?

thanks!!

Russell

Re: automatically click a button in another application

David Crow15-Oct-08 10:57

David Crow

15-Oct-08 10:57

How about sending a BM_CLICK message to that other window?

"Love people and use things, not love things and use people." - Unknown

"The brick walls are there for a reason...to stop the people who don't want it badly enough." - Randy Pausch

Re: automatically click a button in another application

Russell^'15-Oct-08 11:28

Russell^'

15-Oct-08 11:28

Nice suggestion, thanks.
Never done anything like this before, so I started with something easy...but after many test this code it is not seems to work. D'Oh! | :doh:

After that the timer is started I have some seconds to activate the notepad window...but nothing is written there...do you see any error in the way I'm using sendmessage?

void CClickAndCaptureDlg::OnTimer(UINT_PTR nIDEvent)
{
	if(nIDEvent==ID_TIMER){
		{
			TRACE("Timer arrived\n");
			// Stop the timer
			KillTimer(m_Timer);
		}

		// Get the Active Window
		CWnd* pWnd=GetForegroundWindow();
		if(!pWnd) return;

		// Send messages to the other program
		{
			TRACE("Sending messages\n");
			pWnd->SendMessage(WM_CHAR,'H',0);
			pWnd->SendMessage(WM_CHAR,'E',0);
			pWnd->SendMessage(WM_CHAR,'L',0);
			pWnd->SendMessage(WM_CHAR,'L',0);
			pWnd->SendMessage(WM_CHAR,'O',0);
			pWnd->SendMessage(WM_KEYDOWN,VK_RETURN,0);
		}
	}

	CDialog::OnTimer(nIDEvent);
}

Russell

Re: automatically click a button in another application

Russell^'15-Oct-08 11:57

Russell^'

15-Oct-08 11:57

Ok, found the way to use notepad: needed Spy++.
There was the bloblem to find the correct HWND, together to the problem to send the rigth messages.

this code to send a simple 'w'

HWND hc=::FindWindow(CString("Notepad"), NULL);
hc=::GetWindow(hc, GW_CHILD);

::SendMessage(hc,WM_KEYDOWN,0x57,0x110001);
::SendMessage(hc,WM_CHAR,0x77,0x110001);
::SendMessage(hc,WM_KEYUP,0x57,0x110001);

Thank you again Big Grin | :-D

Russell

Spin Control

WayneK10015-Oct-08 9:03

WayneK100

15-Oct-08 9:03

Is there a way to separate the buttons on a spin control? I would like to place them in a horizontal orientation and place the buttons on either side of the text block that displays the value being adjusted.

Thanks

Re: Spin Control

David Crow15-Oct-08 10:58

David Crow

15-Oct-08 10:58

You can orient the spin control either vertically or horizontally, but separating the buttons is not possible.

"Love people and use things, not love things and use people." - Unknown

"The brick walls are there for a reason...to stop the people who don't want it badly enough." - Randy Pausch

Why the activex .ocx can't find msvcr80.dll & mfc80.dll even if I install the 2005 sp1 redist.exe ?

oppstp15-Oct-08 7:11

oppstp

15-Oct-08 7:11

Hello,

I am writing an activex and the activex is about preview the vidoe. So the inside of .ocx code is basically to call the filters to build the filter graph.
But I meet a strange problem now. I use Dependency Walker to find which dll I will redistribute.
The .ocx file need msvcr80.dll and mfc80.dll. The one filter (Ex : a.ax) which is used in the filter graph needs msvcr80.dll.
And I packed all filters which I need into a .cab file and test it on virtual pc first. (The virual pc doesn't install visual studio 2005)
After I unpack the .cab file and install the vcredist.exe(2005sp1).
Then I drag .ocx file into the dependency walker, there are two yellow question mark on the msvcr80.dll and mfc80.dll. So my .ocx file can't be installed.
But if I drag a.ax into the dependecy walker, the msvcr80.dll can be found...

I don't know why it happen. I checked the module search order, two files all use "Side-by-Side components" first. But one can find the msvcr80.dll, the other can't.
Even if I copy the msvcr80.dll and mfc80.dll into the directory which .ocx file exists. Two yellow question mark disappers but I still can't register it.
The error is "This application has failed to start because the application configuration is incorrect. Reinstalling the application may fix this problem"

I also check the manifest file of .ocx (ProgramNameActiveX.ocx.intermediate.manifest), but it contains three dependency item.
The three items are(name='Microsoft.VC80.CRT', name='Microsoft.VC80.MFC', name='Microsoft.VC80.DebugCRT')
Why ? I am very sure that I use the release mode to build the .ocx. Why VC80.DebugCRT appear ? Is this may be the fail reason ?

I don't know how to solve this strange problem. I tried find some data on the internet and tried some methods, such as
put the Microsoft.VC80.CRT.manifest and Microsoft.VC80.MFC.manifest together with the .ocx file.
Or put the ProgramNameActiveX.ocx.intermediate.manifest together with the .ocx file.
But all are failed...

I also thought it might be the project setting. But I don't know how to modify the project setting.

Now the activex can be installed only on the machines which is installed visual stuido 2005.
But my goal is to let it can be installed on the machine without visual studio 2005.

Does anyone may have the suggestion to help me to solve this problem ?

My environment of development : visual studio 2005 sp1 + ms platform sdk 2003 sp1
environment of virtual pc : xp sp3

Thanks a lot.

Re: Why the activex .ocx can't find msvcr80.dll & mfc80.dll even if I install the 2005 sp1 redist.exe ?

oppstp16-Oct-08 0:07

oppstp

16-Oct-08 0:07

My problem is solved now.

It might be the reason of wrong manifest file.
I solved this problem by commenting on the lstrcpyn() function. This function is used for querying the filter name.

After this step, the ProgramNameActiveX.ocx.intermediate.manifest contains two dependency item (Microsoft.VC80.CRT and Microsoft.VC80.MFC)
And the .cab can be installed correctly.

If I don't comment on this function, there will be a warning message.
msvcrt.lib(cinitexe.obj) : warning LNK4098: defaultlib 'msvcrtd.lib' conflicts with use of other libs; use /NODEFAULTLIB:library
Then the ProgramNameActiveX.ocx.intermediate.manifest contains three dependency item. (Microsoft.VC80.CRT, Microsoft.VC80.MFC and Microsoft.VC80.DebugCRT)
Then the .cab can't be installed correctly and the.ocx can't be registered by hand.

But I still don't know why comment on this code can let the program work.
The sample "AudioCap" in platform sdk use this function too.
I also checked the project setting about Runtime Library. My project is the same as the sample "Audio Cap".
But the sample can work without adding the comment.

MFC App (Visual Studio 6) hangs when you click File, Open.

Keith (MapMan)15-Oct-08 5:37

Re: MFC App (Visual Studio 6) hangs when you click File, Open.

15-Oct-08 5:37

I have an MFC, multi-document template application, built using Visual Studio 6, which has been working for a long time now. Recently I moved to a new development machine and now my application hangs whenever I click the File menu and choose Open.

I have run it in debug mode and traced into the MFC code. The point of failure is in DlgFile.cpp(part of Microsoft's MFC source) at line 108 where it calls ::GetOpenFileName(&m_ofn). It goes in there never to return.

I spotted that the m_ofn structure points at a hook function _AfxCommDlgProc so I set a break point in that. The dialog receives the following windows messages before the application hangs: WM_SETFONT, WM_INITDLG, WM_SHOWWINDOW, WM_WINDOWPOSCHANGING, WM_NCCALCSIZE, WM_CHILDACTIVATE, WM_WINDOWPOSCHANGED then WM_SIZE. The WM_SIZE message is processed OK and AfxCommDlgProc then exits back to code for which source is unavailable. My dialog never receives another message.

As a control I then tried exactly the same experiment on another MFC application of mine - one which doesn't fail. It acts exactly the same except that the WM_SIZE message is followed (after a short but noticable delay) by a WM_SETREDRAW after which the Open File dialog box appears.

If I let the failing application hang then click on Debug, Break, the call stack is singularly uninformative:
NTDLL! 7c90eb94()
USER32! 7e4195f9()
USER32! 7e4196a8()
BROWSEUI! 75f8afc9()
BROWSEUI! 75f8b591()
SHLWAPI! 77f69588()
NTDLL! 7c927545()
NTDLL! 7c927583()
NTDLL! 7c927645()
NTDLL! 7c92761c()
KERNEL32! 7c80b683()

I am at my wits end. I am using the standard MFC file open mechanism with no undue cleverness. I can see no tangible difference between the failing application and a different application which works, apart from the file types it's looking for. Has anyone any sensible suggestions what to try next?

Keith

Mark Salsbery15-Oct-08 6:04

Re: MFC App (Visual Studio 6) hangs when you click File, Open.

15-Oct-08 6:04

Does it timeout and eventually show or hang forever?

Is it waiting for a reply from a network drive?

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Keith (MapMan)15-Oct-08 6:12

Re: MFC App (Visual Studio 6) hangs when you click File, Open.

15-Oct-08 6:12

Mark Salsbery wrote:
Does it timeout and eventually show or hang forever?

Is it waiting for a reply from a network drive?

So far as I know it hangs forever - but forever is a long time Smile | :)

I may just not have stuck around long enough.

I don't think it's a network drive issue because I have two similar applications. One always hangs and the other always works. There is clearly a tangible difference between the two but I can't figure out what it is.

Keith

Mark Salsbery15-Oct-08 6:22

Re: MFC App (Visual Studio 6) hangs when you click File, Open.

15-Oct-08 6:22

Does this code ripped right from the docs fail as well?

TCHAR szFilters[]= _T("MyType Files (*.my)|*.my|All Files (*.*)|*.*||");
CFileDialog fileDlg(TRUE, _T("my"), _T("*.my"),
   OFN_FILEMUSTEXIST | OFN_HIDEREADONLY, szFilters);
if(fileDlg.DoModal() == IDOK)
{
}

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Keith (MapMan)15-Oct-08 6:45

Re: MFC App (Visual Studio 6) hangs when you click File, Open.

15-Oct-08 6:45

Mark

I was wrong. It doesn't hang forever. I decided to leave it whilst running a stop watch. After clicking File, Open there is (on my laptop) a 1 minute and 50 seconds delay before the standard open dialog appears. This is solidly repeatable. If I cancel the open-file dialog and then click File Open again then there is another 1:50 delay until the open-file dialog reappears.

I pasted in your code snippet and that also takes nearly 2 minutes before the dialog appears so it's not the filters which are the problem. The identical code, pasted into another application, works without any delay.

Keith

Mark Salsbery15-Oct-08 6:54

Re: MFC App (Visual Studio 6) hangs when you click File, Open.

15-Oct-08 6:54

Keith (MapMan) wrote:
The identical code, pasted into another application, works without any delay.

That's not good Smile | :)

I'm thinking...

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Keith (MapMan)15-Oct-08 7:12

Re: MFC App (Visual Studio 6) hangs when you click File, Open.

15-Oct-08 7:12

>>I'm thinking...
I'm giving up for today so no rush. One more bit of information. File Save As exhibits same long delay before displaying dialog.

Keith

Keith (MapMan)15-Oct-08 22:55