Enable C++ Exceptions - C / C++ / MFC Discussion Boards

Re: How to replace a CDC of another CWnd

Hamid_RT2-Aug-07 5:09

2-Aug-07 5:09

Well you can use of hwnd on the GetDC that retrieves a handle to dc of current window did you try with it HDC hdc=::GetDC(hWnd);.

WhiteSky

Re: How to replace a CDC of another CWnd

Iain Clarke, Warrior Programmer1-Aug-07 23:23

Iain Clarke, Warrior Programmer

1-Aug-07 23:23

hDC = ::GetDC (hWnd);
// do your thing!
::ReleaseDC (hWnd, hDC);

Sometimes its simpler that you think!

You should also have a peek at WM_PRINT, as it asks the other window to draw itself nicely in a DC you provide.

Iain.

Re: How to replace a CDC of another CWnd

FlyingBear2-Aug-07 0:25

FlyingBear

2-Aug-07 0:25

Thanks, i tried the WM_PRINT way, code like this:

<br />
CDC dc;<br />
dc.CreateCompatibleDC(NULL);<br />
CBitmap bmp;<br />
CRect rc;<br />
pWnd->GetClientRect(rc);<br />
bmp.CreateBitmap(rc.Width(), rc.Height(), 1, 24, NULL);<br />
HBITMAP hbmp = (HBITMAP)dc.SelectObject(bmp.GetSafeHandle());<br />
pWnd->SendMessage(WM_PRINT, WPARAM(dc.GetSafeHdc()), PRF_CHILDREN);<br />
CxImage imgSnapshot;<br />
imgSnapshot.CreateFromHBITMAP(bmp);<br />

But the resulted image seems invalid, does that require the target window to write code for processing WM_PRINT message, otherwise it doesn't work?

Re: How to replace a CDC of another CWnd

Mark Salsbery2-Aug-07 9:27

Mark Salsbery

2-Aug-07 9:27

Shouldn't you use the window rect instead of the client rect?

What's wrong with the resulting bitmap?

Did you un-select the bitmap from the DC?

This works for me:

CWindowDC WindowDC(this);
CDC MemoryDC;
MemoryDC.CreateCompatibleDC(&WindowDC);
CBitmap WindowBitmap;
CRect WindowRect;
GetWindowRect(&WindowRect);
WindowBitmap.CreateCompatibleBitmap(&WindowDC, WindowRect.Width(), WindowRect.Height());
CBitmap *pOldBitmap = MemoryDC.SelectObject(&WindowBitmap);
SendMessage(WM_PRINT, (WPARAM)(HDC)MemoryDC, PRF_ERASEBKGND | PRF_CHILDREN | PRF_CLIENT | PRF_NONCLIENT);

//**test**
BitBlt(WindowDC,100,100,WindowRect.Width(), WindowRect.Height(), MemoryDC, 0, 0, SRCCOPY);
//**end test**

MemoryDC.SelectObject(pOldBitmap);

Mark

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

Re: How to replace a CDC of another CWnd

Michael Dunn2-Aug-07 8:18

Michael Dunn

2-Aug-07 8:18

Check out PrintWindow()

--Mike--
Visual C++ MVP Cool | :cool:

LINKS~! Ericahist | PimpFish | CP SearchBar v3.0 | C++ Forum FAQ

Hungarian notation FTW

Re: How to replace a CDC of another CWnd

FlyingBear2-Aug-07 8:53

FlyingBear

2-Aug-07 8:53

Thanks, this does not work for all the applications, I guess it uses SendMessage(WM_PRINT) internally.

Re: How to replace a CDC of another CWnd

FlyingBear2-Aug-07 19:21

FlyingBear

2-Aug-07 19:21

Problem solved, thanks for all your help Smile | :)

Enable C++ Exceptions

Tal S.1-Aug-07 22:37

Tal S.

1-Aug-07 22:37

Hello,

I have old VC6 compiled at VS2005.

I would like to keep 'Enable C++ Exceptions' = Yes (/EHsc) option at the project properties.

One of the functions: __event - is not compiled.

Do you know if I can use another function? Should I do any changes?

Thanks!

Re: Enable C++ Exceptions

Russell^'2-Aug-07 2:35

Russell^'

2-Aug-07 2:35

Are you not using the statement try-catch?
like:

try{
...
}catch(CMemoryException +pErr){
...
}

Russell

Running 10 threads at a time

neha.agarwal271-Aug-07 22:22

neha.agarwal27

1-Aug-07 22:22

Hi all,

I have made a for loop which has to execute 200 times. In that loop i have a started a worker thread. Now what i want is after 10 times that loop should wait for 1 of the thread to finish and then start next thread i.e only 10 thread can execute at a time.How to do it??

Thanks in advance

Re: Running 10 threads at a time

Iain Clarke, Warrior Programmer1-Aug-07 22:48

Iain Clarke, Warrior Programmer

1-Aug-07 22:48

I;d question your design decision as desiribed, but I'll assume your simplifying your actual problem.

Thread handles also act as signalling handles.

So:

....
    HANDLE hThread [MAX] = { NULL, NULL, ... NULL };
    DWORD dwID [MAX];

    for (nTest = 0; nTest < 10; nTest++)
    {
        hThread [nTest] = CreateThread (......., &(dwID [nTest], lParam);
        if (!hThread [nTest])
        {
            Handle error somehow
        }
    }

    for (nTest = 10; nTest < XXXXX; nTest++)
    {
        dwWait = WaitForMultipleObjects (hThread, 10, INFINITE);
        if (dwWait >= WAIT_OBJECT_0 && dwWait < WAIT_OBJECT_0+10)
        {
           nThread = dwWait - WAIT_OBJECT_0;
           hThread [dwThread] = CreateThread (......., &(dwID [nThread], lParam);
           if (!hThread [nTest])
           {
               Handle error somehow
           }
        }
    }

/pre>

Tada!

Iain.
<div class="CPhogPost"></div> 

<div class="ForumSig"></div>

Re: Running 10 threads at a time

Iain Clarke, Warrior Programmer1-Aug-07 22:52

Iain Clarke, Warrior Programmer

1-Aug-07 22:52

I would also point out that I have answered your question very literally. My answer would block your initial thread, is very fragile, etc.

Much better would be to look into thread pools (which I have no experience of), of have your thread posting a "I'm done!" message to a UI main thread, which would then fire off another thread. You could then give the user a more interactive experience, without thinking the process has hung. It would also allow you to handle failure more gracefully.

Iain.

Re: Running 10 threads at a time

Russell^'1-Aug-07 22:57

Russell^'

1-Aug-07 22:57

You can use a variable to count the threads

Global declaration:

<code>volatile </code>UINT RunningThread;   //Create the counter

The main function:

foo(){
RunningThread=0;   //Reset the counter
for(i=0;i<200;i++){
   if(RunningThread<10){
      //Create Thread
      RunningThread++;   //Incremente the counter
   }else{
      wait(100);
      i--;
      continue;
   }
}
}

The thread:

Thread(...){
//Work process
RunningThread--;  // Before it ends decrement the counter
}

Russell

Re: Running 10 threads at a time

neha.agarwal272-Aug-07 2:09

neha.agarwal27

2-Aug-07 2:09

i tried Russell's procedure but its hanging my application and not solving my problem completely....in my thread i m finding out a particular website's html code so, because of so many threads trying to do it, many times it gives page cannot be displayed....how to solve it

Re: Running 10 threads at a time

Russell^'2-Aug-07 2:27

Russell^'

2-Aug-07 2:27

Probally you have to use a semaphore to use the connection in a more efficient way, limiting the simultaneus request to the web.
You can use for example a boolean variable (like BOOL ConnectionIsBusy). If a thread find it TRUE then it waits that it becomes FALSE, then it lock itself the flag to TRUE, talk with the web, and at the end restore the flag value to FALSE.

A similar way is to limit the number of simultaneus connections using a variable like UINT ConnectionsNumber, that you could use to check that the connection opened are less of a particular value (i.e. 2 or 4).

But the problem depends also on the speed of your connection and/or the amount of traffic that you need to exchange with the web. You have to do some tests.

Russell

Re: Running 10 threads at a time

Mark Salsbery2-Aug-07 8:31

Mark Salsbery

2-Aug-07 8:31

Another way to implement Russell's suggestion is to use an I/O Completion Port[^]

This essentially combines a thread pool with a semaphore. With an I/O Completion Port you could
easily create a pool of 10 threads and queue up 200 operations to be executed by the threads as
they become available.

Mark

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

WM_INITDIALOG in VS 2005

vipin_nvk1-Aug-07 22:20

vipin_nvk

1-Aug-07 22:20

Hello

I am VS 2005 for the first time. I have selected a Dialog based application which uses MFC and I want to add a WM_INITDIALOG message handler. We use "Ctrl + W" for VC 6 to invoke class wizard and add a message handler for WM_INITDIALOG.

But in VS 2005, I selected properties of the dialog and looked under the "Messages" tab and dint find the WM_INITDIALOG message to add a handler for that. Do should I do this in VS 2005 ?

Thanx

Re: WM_INITDIALOG in VS 2005

Anurag Gandhi1-Aug-07 22:51

Anurag Gandhi

1-Aug-07 22:51

Add a class for the dialog if not added.

Go to Class view, Right click that class, go to property, then you will find all the virtual functions in the 3rd tab.

Anurag Gandhi.
http://www.softgandhi.co.nr

Re: WM_INITDIALOG in VS 2005

KarstenK1-Aug-07 23:49

KarstenK

1-Aug-07 23:49

I still miss the Class wizzard with its "Ctrl+W" feature. Cry | :((

IMHO this is a sign how carefully sometimes the job is done in the big M$-code machine Confused | :confused:

Greetings from Germany

How can i get Partition name from partition number?

Banks K1-Aug-07 22:03

Banks K

1-Aug-07 22:03

Hello All,

i have to find Partition name like(New Volume(K Smile | :)

) but by using partition number because i am having PARTITION_INFORMATION structure in the project.

now i am unable to get PArtition Name by using Partition Number.

if you have any idea about this please please share with me.

thanks
bankey

Re: How can i get Partition name from partition number?

Naveen1-Aug-07 23:48

Naveen

1-Aug-07 23:48

the volume name can be found out from the from GetVolumeInformation(). This function requires the drive letter not the partion number.If you manage to get the drive letter, you can get the volume name.

If there is no staright way for doing this, you can use the below method.

You can use the QueryDosDevice() function to find the diive letter from parition name. for eg consider the below code. If 'c' is the first partion, the tcDeviceName will contain \Device\HarddiskVolume1. and if you give 'd:', it will be \Device\HarddiskVolume2 and so on
TCHAR tcDeviceName[50];
QueryDosDevice( _T("C:"), tcDeviceName, 50 );

suppose you got 1 in the PARTITION_INFORMATION. then make string like "\Device\HarddiskVolume1". Now starting from A to Z, put a loop and call the QueryDosDevice. Compare the device name with the "\Device\HarddiskVolume1". If it matches, you have the drive letter.

nave

[OpenedFileFinder]

Interrupts in windows

zon_cpp1-Aug-07 21:35

zon_cpp

1-Aug-07 21:35

Hello there!
i work in VC++ and i want to write an asm code in my code
in this code, i want to write an interrupt,
i don't know list of interrupts in windows system???

I'd like to know how I can find the IDT addresses?
how do i access to this address (IDT) and how do i change address of an interrupt? (whit assembly code)

Zo.Naderi-Iran

Re: Interrupts in windows

Hamid_RT1-Aug-07 21:40

Hamid_RT

1-Aug-07 21:40

zon_cpp wrote:
list of interrupts in windows system

See here[^] does helpful?

WhiteSky

how can i control the sound of left and right speaker

rajneshmalik1-Aug-07 21:11

rajneshmalik

1-Aug-07 21:11

hi
how can i control the sound of left and right speaker by vc++/mfc.Actually i want to send different sound at same time on left and right speaker.

if anybody reply me i will obliged

malik

Re: how can i control the sound of left and right speaker

Hamid_RT1-Aug-07 21:37

Hamid_RT

1-Aug-07 21:37

See MIXERCONTROLDETAILS does your answer?

WhiteSky

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