C / C++ / MFC Discussion Boards

Re: How to access remote database server from windows service

zhaopi11-Jul-05 15:12

11-Jul-05 15:12

Sorry,what does this mean? Does that means i need to impersonate an account to have the permission to access the database before connection?

Pass structure to C#

Member 12566510-Jul-05 23:44

Member 125665

10-Jul-05 23:44

I want to create a DLL in C++/VC++.
This dll will be called from C#.

How i will create it and how i will pass C++ structure as a parameter to my function.

Re: Pass structure to C#

Andy Moore12-Jul-05 7:21

Andy Moore

12-Jul-05 7:21

--Your C++ code would look like the following

typedef struct St
{
     int a;
     int b;
}

__declspec(dllexport) void SetMyStruct( St* s );

--Now, in your c# code you would do the following:

[System.Runtime.InteropServices.LayoutKind(LayoutKindSequential)]
public struct St
{
    public int a;
    public int b;
}

public class MyClass
{
    [DllImport("mydll.dll")]
     public static extern void SetMyStruct( ref St s );
}

I hope this helps.

Human beings were not meant to sit in little cubicles staring at computer screens all day, filling out useless forms and listening to eight different bosses drone on about about mission statements. -- Peter Gibbons

WSASocket problem in XP Pro

Anonymous10-Jul-05 23:32

Anonymous

10-Jul-05 23:32

Hoping someone can direct me to a solution on this. I have developed a pretty basic Client/Server system using Winsock2 using TCP (aka SOCK_STREAM)and when the client application of our system is installed and run on XP Pro, the application fails to open the socket when calling WSASocket. This has happened on two different machines. This problem does not occur on XP Home nor on Win2K Pro. Both of the problem machines have been upgraded to SP2.

Here is the code:

Socket = WSASocket (AF_INET,
SOCK_STREAM,
IPPROTO_TCP,
NULL, // LPWSAPROTOCOL_INFO lpProtocolInfo
0, // GROUP (reserved)
0); // DWORD dwFlags

This call in XP Pro returns INVALID_SOCKET and a subsequent call to WSAGetLastError() returns 0 which means it was successful. Hogwash. Need help on this.

Thanks,

Mike

How to print to virtual printer from Window Service (in not login state)

Anonymous10-Jul-05 23:29

Anonymous

10-Jul-05 23:29

Hi,
RepliGo is a utility that allow you to convert Office file to RepliGo file for reading them in Palm.
RepliGo provide a virtual printer for us to do that work.
I'm using RepliGo's virtual printer to convert (.DOC, .XLS, .PPT) file to .RGO file.

I used DDE command to do that work. For example, with .DOC file, I have DDE command :
-------------------------------------------------------------------------
[REM _DDE_Minimize][FileOpen("%1")][t=IsDocumentDirty()][FilePrint 0][SetDocumentDirty t][DocClose]
-------------------------------------------------------------------------
(Can find it in Window Registry)

And I used classExec utitlity to run that DDE command.

My application is built as the server/client model. Server run as windows service.

My problem is:

+ When I login Window with specified user, from client, I can convert all files summarised before to .RGO.

+ But when I restart, not yet login window (at login form), from client, I can't convert them.
(May be I have not logged in Window yet, so I don't have DESKTOP for RepliGo's virtual printer to run)

Please tell me what to do with this problem.

Thanks a lot.

Button activation

antoine_david10-Jul-05 22:07

antoine_david

10-Jul-05 22:07

I would like to activate a button only when my boolean "bActive" is true(he is false at initialisation).
How can i do that?

Thanks in advance Smile | :)

Re: Button activation

Cedric Moonen10-Jul-05 22:17

Cedric Moonen

10-Jul-05 22:17

In your dialog class:

GetDlgItem(IDC_YOURBUTTON)->EnableWindow(bActive);

Hope this helps

Re: Button activation

antoine_david10-Jul-05 22:22

antoine_david

10-Jul-05 22:22

thanks you Big Grin | :-D

Rectangle Selection

javi_jmc10-Jul-05 21:33

javi_jmc

10-Jul-05 21:33

Hi everybody,

I would need your help...I have to create a rectangle on clicking LEFT-Button of the mouse and tracking it over the screen. I mean, the typical one that appears when you select, for instance, several icons on the desktop. I want to do this to get the coordenaes of the rectangle made by the user. How can I do it?

In this site :

http://www.codeguru.com/Cpp/G-M/gdi/article.php/c139/

It explains how to do it, the problem is that if you execute the application you will see that when you move the mouse to create the rectangle, the program doesn't erase the previous rectangle before tracking the mouse. How can I do to delete the previous rectangles? Or could you give a link to search for it?

Thanks,

Javi

Re: Rectangle Selection

Jose Lamas Rios11-Jul-05 2:40

Jose Lamas Rios

11-Jul-05 2:40

This is usually done calling DrawFocusRect. Before drawing a rectangle with it, you first call it with the previous rectangle coordinates, which erases the last drawing.

--
jlr
http://jlamas.blogspot.com/[^]

Re: Rectangle Selection

Blake Miller11-Jul-05 4:57

Blake Miller

11-Jul-05 4:57

Study Jospeh Newcomer's 'better zommin' for some really good ideas on how to select a rectangle.
http://www.codeproject.com/tools/betterzoomin.asp[^]

MFC Calling .NET

quesansii10-Jul-05 20:31

quesansii

10-Jul-05 20:31

Hi All,

Can anyone help me how to make a VSC++(6.0) ActiveX Dll that will be calling VB.Net ActiveX Dll? Example I want to pass 2 parameter Strings to a C++ class/function with a value of "2" and "1". Inside the c++ dll, it will call the vb.net activeX dll that will sum the 2 nos. and will return 3 of float data type to the c++ dll.

your answer will be very much appreciated.

Thanks

Making a dialog over everything - even games

awah10-Jul-05 20:30

awah

10-Jul-05 20:30

how do you guys make a dialog window overlap everything? even games?

i understand the command

CDialog::SetWindowPos&wndTopMost,0,100,0,0,SWP_NOACTIVATE|SWP_NOSIZE);

but it does not overlap games

i have seen advertisers like netzero advertisements managed to overlap everything even games in full screen mode

SetWindowPos is insufficient in this case
what's is the easiest way to do this overlapping feat?

please advise Smile | :)

Re: Making a dialog over everything - even games

David Crow11-Jul-05 3:11

David Crow

11-Jul-05 3:11

Will a system-modal dialog work?

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

Re: Making a dialog over everything - even games

awah12-Jul-05 17:20

awah

12-Jul-05 17:20

nope it doesnt
it's the same as the windowsetpos command above

a paradox in mfc head file?

wrb30210-Jul-05 20:29

wrb302

10-Jul-05 20:29

problem code:

pMetaFileDC->SelectObject(newPen);

when debug, it causes an assertion. the source is:

{ ASSERT(m_hDC == m_hAttribDC); // ASSERT a simple CDC object
return (hObject != NULL) ? ::SelectObject(m_hDC, hObject) : NULL; }

ok, then i write this:

pDoc->pMetaFileDC->SetAttribDC(pDoc->pMetaFileDC->GetSafeHdc());

but this fuciton do not work as supposed. and the assertion remains.

look into the source code:

void CMetaFileDC::SetAttribDC(HDC hDC) // Set the Attribute DC
{
if (hDC != m_hDC)
CDC::SetAttribDC(hDC);
if (m_hDC == m_hAttribDC) // if we somehow got to this, correct it
ReleaseAttribDC();
}

i am really confused! what am i supposed to do?

in addition, if i do nothing but use the release vision, i find it works quite well without any problem.

reference this:http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vsdebug/html/_core_the_trace_macro.asp[^]

Re: a paradox in mfc head file?

David Crow11-Jul-05 3:44

David Crow

11-Jul-05 3:44

wrb302 wrote:
in addition, if i do nothing but use the release vision, i find it works quite well without any problem.

Wrong. The problem still exists. The reason you do not see it is because the ASSERT() macro has been removed by the preprocessor in Release mode.

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

Question about displaying a property page

PrashantJ10-Jul-05 20:14

PrashantJ

10-Jul-05 20:14

Hi,

In my application I draw a property page, and hit a button on this property page to open a new dialog(which will close the property page). Now I want to show the property page on a button click from this new dialog. For which I have code in OnButtonBlickInThisNewDialog as

propSheetPtr->DoModal();

But the prop sheet is not showing up, instead seems like its being displayed for a fraction of a second and goes off. I checked the value of this propSheetPtr it is not deleted, i.e. prop sheet pointer still has the same values as it had when displayed earlier

Also tried
propSheetPtr->ShowWindow(SW_SHOW)
but the property sheet does not stay (displayed!)

Can anybody help me out for this issue?

Thanks.

About building a Windows service

zhaopi10-Jul-05 20:04

zhaopi

10-Jul-05 20:04

I am about to implement a windows background service.
I have succeeded to build the basic functions such as creating, stopping and deleting the service.

The service is actually built basing on an infinite while loop (while(1)),
if i put some simply operation like file processing in the while loop, it works fine~
when i put this line "doc. getdocumentlist(doclist, 9);" in, the program just stops there and cannot proceed to the codes below( this can be seen from the log file content).

Can anybody explain this to me...

void cService::EndlessLoop()<br />
{<br />
Output("EndlessLoop Start\n");<br />
SYSTEMTIME Clock;<br />
CString Out;<br />
Cdocumentdb doc;<br />
// This endlessloop is killed by Windows when the service is stopped or shutdown<br />
while (1)<br />
{<br />
if (hTimer != 0)<br />
{<br />
LARGE_INTEGER Elapse;<br />
Elapse.QuadPart = -10000000; // 5 Seconds in 100 Nanoseconds resolution (negative=relative)<br />
BOOL Res = ::SetWaitableTimer(hTimer, &Elapse, 0, 0, 0, TRUE);<br />
<br />
if (Res)<br />
{<br />
DWORD Event = WaitForSingleObject(hTimer, 30000); // 30 seconds timeout<br />
// Event = (258=WAIT_TIMEOUT) (128=WAIT_ABANDONED) (0=WAIT_OBJECT_0) (0xFFFFFFFF=WAIT_FAILED)<br />
}<br />
}<br />
CArray<CString, CString>  doclist;<br />
		<br />
doc. getdocumentlist(doclist, 9);<br />
<br />
::GetLocalTime(&Clock);<br />
Out.Format("Timer %02d:%02d:%02d:%03d", Clock.wHour, Clock.wMinute, Clock.wSecond, Clock.wMilliseconds);<br />
Output(Out);<br />
};<br />
}

Re: About building a Windows service

zhaopi10-Jul-05 20:07

zhaopi

10-Jul-05 20:07

sorry, forgot to say,
what the "doc. getdocumentlist(doclist, 9);" is to retrieve some information from a database table...

Re: About building a Windows service

Blake Miller11-Jul-05 5:02

Blake Miller

11-Jul-05 5:02

Does your code work when it is NOT placed into a service?
If that is true, then it could be a permissions issue.
You might need to make sure the service runs under an account that has the proper privileges and security to access the database.

16bit & 32bit Portability issues

Anonymous10-Jul-05 19:25

Anonymous

10-Jul-05 19:25

Hi,

I have the following code written for a target compiler (Keil compiler) which uses 16 bits:

-----------------------
signed short int a, b, c;

a = (b + c) / 2;
-------------------------

With the inputs for b = 30720, c = 30720,

i) when VC++ compiler is used, the value of a is evaluated as 30720.

ii) However, when using the Keil compiler, the value of a is evaluated as -2048. This is due to the fact that the calculated value of (b + c) is 61440 and as this value lies above the valid range of signed short int, it gets wrapped to -4096 before division by 2. This value after division becomes -2048.

Now my concern is that if there exists any settings in VC++ compiler environment so that I get the same value for the variable 'a' as that of Keil environment. An early response would be appreciated.

Re: 16bit & 32bit Portability issues

David Crow11-Jul-05 3:51

David Crow

11-Jul-05 3:51

A signed short int is the same as a __int16 type in VC++. The range is –32,768 to 32,767. For the VC++ compiler to produce the correct result, it looks like it is promoting (b + c) to a signed int first so that it does not overflow.

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

Notification on CPU frequency change in SpeedStep

Vitaly Kashkarov10-Jul-05 19:09

Vitaly Kashkarov

10-Jul-05 19:09

Hi,
Does anyone know if it is possible to get notification from Windows in the
event of change of CPU frequency driven by Enhanced SpeedStep technology?
It would be nice to hook a callback function to the event so that I would
know at any time what CPU frequency my laptop is running at.

Vitaly Kashkarov

DirectSound Question

Mark Keeling10-Jul-05 17:58

Mark Keeling

10-Jul-05 17:58

I am having problems getting SetVolume to change the volume of my sound buffers.

When my program starts it scrolls though a database that holds the filename, pan, and volume settings for each sound, loads these sounds in secondary buffers, and then sets the pan and volume for each individual sound. Several sounds will be loaded at once.

Once the sounds are loaded the pan and volume can be changed with slider controls and drop lists. Both of which work correctly. My problem is on program init.

When the program starts, the position of the slider control for the volume gets set to the correct position (0-100% volume), but the volume is always played at 100%. The pan on the other hand always works correctly and the sound is played on the correct left or right speaker.

I think that SetVolume is working however, because if I change the pan without changing the volume slider, the volume changes to what it should have been.

Any ideas?

Mark Keeling

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