C / C++ / MFC Discussion Boards

Re: How can I Get Value of SPDRP_LEGACYBUSTYPE ?

002comp11-Jun-13 22:31

11-Jun-13 22:31

Thanks jochen for your Reply.
I tried ur way but it is not the value that I was looking For.

May be you can give more Ideas. here is what I want. When I right Click on USB Device from Device manager,it open up properties Dialog where we can select property and its value. Here, I found one property "bus relation" which I am trying to get using SetupDi calls.

Bus relation value is showing like this :
USBPRINT\CANONIP4200\6&19ACF&0&USB001

This is the device Instance Id.
But when I tried to get same using SetDiGetDeviceInstanceId,it gives me like
USB\VID_04A9&PID_10A2\C34BBD

How can I get USBPRINT\CANONIP4200\6&19ACF&0&USB001 ?

Regards
Y

Re: How can I Get Value of SPDRP_LEGACYBUSTYPE ?

Jochen Arndt11-Jun-13 23:16

Jochen Arndt

11-Jun-13 23:16

At first you may read Retrieving Device Relations[^] for some background on device relations.

Some googling found this site http://www.techtalkz.com/microsoft-device-drivers/262178-getting-bus-relations-device.html[^] which may help you.

Re: How can I Get Value of SPDRP_LEGACYBUSTYPE ?

002comp12-Jun-13 22:12

002comp

12-Jun-13 22:12

Thanks A Lot jochen
I followed your post and get succeed in getting Bus Relation value[Device Id] which gives me Printer name.

Thank you Very Much Again.

Regards
Y

Re: How can I Get Value of SPDRP_LEGACYBUSTYPE ?

Jochen Arndt13-Jun-13 0:27

Jochen Arndt

13-Jun-13 0:27

Nice to hear that you solved the problem and thank you for the feedback.

corrupt __vfptr from dynamic loaded DLL

Joerg Michels11-Jun-13 3:48

Joerg Michels

11-Jun-13 3:48

Hi,

I working on a plugin system for a MFC C++ application. So I started with a small plugin DLL with a simple function creating an object of a class with virtual functions and returning that object to the caller. The object is created on the heap and actually a pointer to the object is returned.

In the main application a function loads the plugin (LoadLibrary), searches the exported function (GetProcAddress) and executes the function. As result the created object is available, as expected. So far so good.

Btw: the class is already declared in a different DLL linked by both the main application and the plugin DLL.

Next I want to unload the plugin with FreeLibrary.

That leads to the problem of a corrupt vftable of the created object. I found out, that the __vfptr is in the memory of the plugin DLL and so unloading the DLL destroys that memory and the __vfptr is not usable anymore.

Is there any way to change that behaviour?

with kind regards,

Joerg

Re: corrupt __vfptr from dynamic loaded DLL

Richard MacCutchan11-Jun-13 4:12

Richard MacCutchan

11-Jun-13 4:12

In a word: No. If the object is created from a DLL that was dynamically loaded, then you must not unload the library until all instances of the class have been deleted.

Use the best guess

Re: corrupt __vfptr from dynamic loaded DLL

pasztorpisti11-Jun-13 10:58

pasztorpisti

11-Jun-13 10:58

If you unload the DLL then you remove all code from memory that represents the implementation of class methods including the actual vtable that points to these methods. Another important thing: the code that deletes the object should be in the DLL (same is true for object creation, normally you create an instance by calling an exported dll method)! One good solution to that is putting a Release() method into your class and Release() could simply do the "delete this;" stuff. Delete all class instances before unloading the DLL.

Re: corrupt __vfptr from dynamic loaded DLL

Freak3012-Jun-13 2:55

Freak30

12-Jun-13 2:55

You could create a static function in the dll where the class is defined. This function would create the object inside the dll with parameters from the plugin. It returns the pointer to the plugin who passes it to the application. This way the object should be defined entirely in the dll so that you can unload the plugin.

However you should consider, whether it is really necessary to use the plugin unter these circumstances i.e. when the application knows the actual type of the returned object.

IWebBrowser2::Navigate2 problem with IE8 on Win7

narasingubhanu10-Jun-13 23:39

narasingubhanu

10-Jun-13 23:39

Creating webbrowser as below

XML

hret=CoCreateInstance(clsid,NULL,CLSCTX_ALL,IID_IUnknown
        ,reinterpret_cast<void**>(&m_pUnknown));

hret=m_pUnknown->QueryInterface(IID_IWebBrowser2,(PVOID *)&m_pBrowser);
    ASSERT(SUCCEEDED(hret));

but when i say
HRESULT hret = m_pBrowser->Navigate2(varURL,&noArg,&noArg,&noArg,&noArg);
its opening new IE window on WIn7. But in Xp sys its not happening like that. I dont want to open new IE window

Any one has any idea why it is opening on new IE window on Win7

Re: IWebBrowser2::Navigate2 problem with IE8 on Win7

Richard MacCutchan11-Jun-13 2:45

Richard MacCutchan

11-Jun-13 2:45

It's quite possible (and not unknown) for later versions to contain stricter interpretation of optional parameters. The documentation[^] shows how to set the required behaviour.

Use the best guess

Re: IWebBrowser2::Navigate2 problem with IE8 on Win7

narasingubhanu18-Jun-13 22:20

narasingubhanu

18-Jun-13 22:20

I tried a lot on this but couldn't able to resolve this
Can any one help?

Re: IWebBrowser2::Navigate2 problem with IE8 on Win7

Richard MacCutchan18-Jun-13 22:51

Richard MacCutchan

18-Jun-13 22:51

narasingubhanu wrote:
I tried a lot on this but couldn't able to resolve this

Tried what, and what results did you get? Please don't expect people to be able to guess what you have done.

Use the best guess

Re: IWebBrowser2::Navigate2 problem with IE8 on Win7

narasingubhanu18-Jun-13 23:23

narasingubhanu

18-Jun-13 23:23

HRESULT hret = m_pBrowser->Navigate2(varURL,&varFlag,&vFrame,&noArg,&noArg);
I passed browser constants and frame also but still its opening in new window and if i call any browser function after that its crashing
ex:m_pBrowser->get_Busy(&bBusyFlag); //crash application

Re: IWebBrowser2::Navigate2 problem with IE8 on Win7

Richard MacCutchan18-Jun-13 23:33

Richard MacCutchan

18-Jun-13 23:33

You need to use your debugger to find out why it's crashing.

Use the best guess

Re: IWebBrowser2::Navigate2 problem with IE8 on Win7

narasingubhanu18-Jun-13 23:47

narasingubhanu

18-Jun-13 23:47

Thanks for suggession.
if you want compelte problem here it is
I am printing htnl doc from url. In xp with out opening new IE browser we will get file save dialog while printing the doc
File save dialog opens at m_pBrowser->ExecWB(OLECMDID_PRINT,OLECMDEXECOPT_DONTPROMPTUSER,&noArg,&noArg);
at this point if you press Alt+tab you can see IE icon.
but in Win 7 directly opening IE window at Navigate2 function

How to increment the slider while video is playing.?

mbatra319-Jun-13 23:48

mbatra31

9-Jun-13 23:48

Hi,

I am working on a project in which I use DirectShow to Play / Pause / Stop the video. I am using progress bar which increments along with the video. Now I want to use Slider bar instead of the progress bar which should increment along with the video. Also user should be able to control the video using slider (move forward / backward). I had used timers in which I am incrementing the progress bar.

How to use Sliders so that while video is playing, slider should increment along with the video showing the progress of the video.

Anybody have any idea or any sample code for the same.?

Regards,
Mbatra

Re: How to increment the slider while video is playing.?

David Crow10-Jun-13 5:53

David Crow

10-Jun-13 5:53

Have you looked at the CSliderCtrl members? I'm seeing SetRange() and SetPos(), both of which look like they'd be part of the solution.

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modified 10-Jun-13 14:44pm.

Re: How to increment the slider while video is playing.?

mbatra3110-Jun-13 19:52

mbatra31

10-Jun-13 19:52

Hi David,

Thanks for the reply.

These functions we can use to update the position of the slider. I
want to make the slider synchronize with the timer and the duration of the video. At any time when user drags the slider forward or backward, the playing video should also move forward or backward and timer value should also be changed.
You can say, I want the functionality similar to YouTube, playing a video and user can move forward or backward. Accordingly the video and the timer changes their values.

Do you have any sample code for the same.?

Regards,
Mbatra

Re: How to increment the slider while video is playing.?

David Crow11-Jun-13 2:50

David Crow

11-Jun-13 2:50

That article I referenced you to earlier shows how to use the IMediaSeeking::SetPositions() method. You'll call this method when handling the TRBN_THUMBPOSCHANGING message.

Re: How to increment the slider while video is playing.?

ThatsAlok11-Jun-13 3:31

ThatsAlok

11-Jun-13 3:31

mbatra31 wrote:
You can say, I want the functionality similar to YouTube, playing a video and user can move forward or backward. Accordingly the video and the timer changes their values.

you can follow this logic

- get total video length in seconds
- create slider based on resulting time
- handle sliderctrl message http://msdn.microsoft.com/en-us/library/ekx9yz55(v=vs.80).aspx[^]
- move your video time line appropriately

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Re: How to increment the slider while video is playing.?

mbatra3111-Jun-13 3:37

mbatra31

11-Jun-13 3:37

Hi,

I have followed the similar points. At point No.3, I want to forward the video in proportion to the slider value. But issue is how to get IMediaSeeking interface reference to the running video. So that I can set the position of the next seek frame.

Regards,
Mbatra

Re: How to increment the slider while video is playing.?

David Crow11-Jun-13 4:28

David Crow

11-Jun-13 4:28

mbatra31 wrote:
But issue is how to get IMediaSeeking interface reference...

In that DirectShow example I referenced you to (several times now), look at the PlayerClass::Initialise() method. It shows how to get references to three different interfaces, IMediaSeeking included.

Reagarding error with ostream

Manoj73909-Jun-13 20:24

Manoj7390

9-Jun-13 20:24

Hi.. I have implemented ECC algorithm in C++ and it is working fine with g++ compiler... I need to apply this program to network simulator - 3. Complier of NS-3 is "./waf", there it is not building and it is giving countless errors mainly regarding "ostream".

there is a line regarding ostream in my header function....---

XML

// ostream handler
               template<int T>
               friend  ostream&    operator<<(ostream& os, const FiniteFieldElement<T>& g)
               {
                   return os << g.i_;
               }

Re: Reagarding error with ostream

Richard MacCutchan9-Jun-13 21:25

Richard MacCutchan

9-Jun-13 21:25

Manoj7390 wrote:
it is giving countless errors

Without the detail of those errors no one can guess what is wrong.

Use the best guess

Re: Reagarding error with ostream

Manoj73909-Jun-13 21:40

Manoj7390

9-Jun-13 21:40

In the main program i am calling another header function called "FiniteFieldElement.h" function. In that function i have used --

XML

// ostream handler
               template<int T>
               friend  ostream&    operator<<(ostream& os, const FiniteFieldElement<T>& g)
               {
                   return os << g.i_;
               }

I am calling this function and using "ostream" in so many places in main function. I am getting the errors like..

/usr/include/c++/4.6/ostream:493:5: note: template<class _chart,="" class="" _traits=""> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const _CharT*)
/usr/include/c++/4.6/ostream:473:5: note: template<class _traits=""> std::basic_ostream<char, _traits="">& std::operator<<(std::basic_ostream<char, _traits="">&, unsigned char)
/usr/include/c++/4.6/ostream:468:5: note: template<class _traits=""> std::basic_ostream<char, _traits="">& std::operator<<(std::basic_ostream<char, _traits="">&, signed char)
/usr/include/c++/4.6/ostream:462:5: note: template<class _traits=""> std::basic_ostream<char, _traits="">& std::operator<<(std::basic_ostream<char, _traits="">&, char)
/usr/include/c++/4.6/ostream:456:5: note: template<class _chart,="" class="" _traits=""> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, char)
/usr/include/c++/4.6/ostream:451:5: note: template<class _chart,="" class="" _traits=""> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, _CharT)

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