C / C++ / MFC Discussion Boards

Danzy8325-Aug-10 1:13

25-Aug-10 1:13

Is there any function in C++ or C that checks if there is a character in the standard input and returns immediately? I have this application that creates a new thread when it starts working on an assigned task. The new thread asks the user to press some keys for other options as the main thread does its work. What I want is that if the main thread finishes doing its work and the user has not selected any of the options, then the thread that was created to get user options should return. But because the new thread waits for user input, I'm finding it difficult to stop it from waiting for user input so that it can return. I initially thought cin.peek() could do it but it also waits when the user has not press any key. I want a way to terminate the new thread as it waits for input, when the main thread has finished its work. Please help.

Re: Help with Standard Input

CPallini25-Aug-10 1:36

CPallini

25-Aug-10 1:36

_kbhit [^].

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: Help with Standard Input

carter200025-Aug-10 3:05

carter2000

25-Aug-10 3:05

use _getch(), the header file is conio.h

Re: Help with Standard Input

CPallini25-Aug-10 3:23

CPallini

25-Aug-10 3:23

_getch() actually waits for the user input.
Smile | :)

Hide TilteBar CMFCToolBar window

Benjamin Bruno25-Aug-10 0:42

Benjamin Bruno

25-Aug-10 0:42

How to Hide the TilteBar of a window Created Using CMFCToolBar in Floating Style

Re: Hide TilteBar CMFCToolBar window

Sauro Viti25-Aug-10 1:15

Sauro Viti

25-Aug-10 1:15

You can try calling ModifyStyle(WS_CAPTION, 0), but if you remove its title bar you loose the ability to meve it (and then you cannot dock it again by dragging its window near the main window border)...

Size of SDI window in MDI applcation

Anu_Bala24-Aug-10 23:13

Anu_Bala

24-Aug-10 23:13

Hi,
My application is MDI application.
In that im having one SDI view(CGlgPopup) derived it from CFrameWnd.

Now for that view,i want to remove Maximize,minimize button and also i want to set the size of the view as small like 200x200 size.
In PreCreateWindow() of CGlgPopup class,
i did like

cs.style &= ~(WS_MAXIMIZEBOX);
		cs.style &= ~(WS_MINIMIZEBOX);
		cs.style &= ~(WS_CHILDWINDOW); 
		cs.x = xPosVal-60;
		cs.y = yPosVal-50;
		cs.cx = 400;
		cs.cy = 300;

But the expecting result is not coming.
How can i do that?

Anu

CString

raju_shiva24-Aug-10 19:23

raju_shiva

24-Aug-10 19:23

Hi all,
I am trying to trim a string and store the values in some variable.
i.e

I have

CString str = sample(1,2,3,4,5);

I want to store the values as
x1=1,x2=2,x3=3......so on.

Any idea how can i proceed will be thankful

Thanks in advance
Raj

Re: CString

Niklas L24-Aug-10 19:43

Niklas L

24-Aug-10 19:43

I assume you mean

CString str = sample("1,2,3,4,5");

You can use std::stringstream, ::strtok(), CString::Find(), or maybe boost::split(). Try each of them and see how they differ.

home

Re: CString [modified]

Shivanand Gupta24-Aug-10 20:38

Shivanand Gupta

24-Aug-10 20:38

Dear, Firstly assign object of CString correctly.

modified on Wednesday, August 25, 2010 2:44 AM

Re: CString

goorley24-Aug-10 22:34

goorley

24-Aug-10 22:34

What's wrong with assigning a variable from a function call?

Re: CString

CPallini24-Aug-10 23:28

CPallini

24-Aug-10 23:28

No problem, that's

CString sample(int a, int b, int c, int d, int e)
{
  CString str;
  str.Format("%d,%d,%d,%d,%d", a,b,c,d,e);
  return str;
}

CString str = sample(1,2,3,4,5);
// now extract the numbers from the string!

just pure humour!

Re: CString

CPallini24-Aug-10 21:18

CPallini

24-Aug-10 21:18

raju_shiva wrote:
CString str = sample(1,2,3,4,5);

The above instruction is not correct.
Supposing it is:

CString str = "sample(1,2,3,4,5)"

I would use CStringT::Tokenize [^], have a look at the sample code provided.
Smile | :)

Re: CString

raju_shiva24-Aug-10 21:49

raju_shiva

24-Aug-10 21:49

CPallini wrote:
Supposing it is:

CString str = "sample(1,2,3,4,5)"

Actually i am reading it from edit box as a CString.
i.e
CString str = "sample(1,2,3,4,5)"

I am trying with this code

CString str = "sample(1,2,3,4,5)",str1,str2;

str1 = str .Left(str .Find("(")); 
str2 = str .Right(str .Find("("));

str.Left is working fine
I am getting the result as sample

But str.Right i am not getting the required result as 1,2,3,4,5).

I am getting 3,4,5

What i am doing wrong

Thanks
Raj

Re: CString

CPallini24-Aug-10 21:58

CPallini

24-Aug-10 21:58

raju_shiva wrote:
str1 = str .Left(str .Find("("));
str2 = str .Right(str .Find("("));

Change to:

int pos = str.Find("(");
str1 = str.Left(pos);
str2 = str.Right( str.GetLength() - pos - 1);

However, I still would use Tokenize for the overall task.
Smile | :)

Re: CString

raju_shiva25-Aug-10 22:20

raju_shiva

25-Aug-10 22:20

Hi,
Thank you for your reply.
I have used for() loop and find to split the string.

As i am not familar with Tokenize,thats why i did not used it.

Thanks
Raj

Re: CString

Shivanand Gupta25-Aug-10 8:55

Shivanand Gupta

25-Aug-10 8:55

I am giving example as your requirement.
eg.

CString str = "sample(1,2,3,4,5)",str1,str2;
int curPos= 0;
str1 = str.Tokenize("()",curPos);

Output: str1 = 1,2,3,4,5

Using DeleteVolumeMountPoint function.

dipuks24-Aug-10 11:53

dipuks

24-Aug-10 11:53

Hey

I used DeleteVolumeMountPoint function to remove a USB drive (E Smile | :)

from my machine. Now i want to bring that back. I tried re-booting and that doesn't seems to help.

I think calling SetVolumeMountPoint function will bring it back. But that function needs the GUID of USB drive, which i don't have.

Any ideas how to get the USB drive(volume - E:\) back?

Can i do that via regedit? If so, how?

THanks in advance

Re: Using DeleteVolumeMountPoint function.

Peter_in_278024-Aug-10 13:22

Peter_in_2780

24-Aug-10 13:22

Got a system restore point from before you deleted it?
[If not, why not? Poke tongue | ;-P

]

Software rusts. Simon Stephenson, ca 1994.

Re: Using DeleteVolumeMountPoint function.

Sauro Viti24-Aug-10 21:11

Sauro Viti

24-Aug-10 21:11

If you want to do it programmatically, there is some work to do around the SetVolumeMountPoint function.
The easiest way is to do it from the Control Panel: open the Administrative tools and run Computer management, then select the section Disk management. There you can see all the disks, both removable and not; you should right-click on the USB drive and select Change drive letter and path (or Assign drive letter and path, or similar).

Cheers,
Sauro

Re: Using DeleteVolumeMountPoint function.

dipuks25-Aug-10 2:45

dipuks

25-Aug-10 2:45

Hey Sauro,

That worked awesome!

Thanks a lot.

Smile | :)

Trouble with VirtualAlloc

garyflet24-Aug-10 8:30

garyflet

24-Aug-10 8:30

I'm using Visual C++ 6 service pack 6 on XP. According to the documentation for that version, Advanced Windows Extentions (AWE) allows users to access physical memory beyond the 2 GB boundary for a process. There is an example in the documentation:

http://msdn.microsoft.com/en-us/library/aa366531(VS.85).aspx

I've had trouble linking to kernel32.dll to make this work. However, the kernel32.dll(2009) in Windows/system32 has the functions so I used LoadLibrary() to explicitly link to that kernel32.dll. Unfortunately, even on a system with 2.96 GB of RAM, running ONLY the simple example, I cannot get VirtualAlloc() to successfully reserve memory over 1100 MB (it does work at 1100 MB and below). I am using the VirtualAlloc from the 2009 kernel32.dll.

*****
typedef LPVOID (WINAPI *LPVIRT)(LPVOID lpAddress,SIZE_T dwSize,DWORD flAllocationType,DWORD flProtect);
LPVIRT lpVirt;
HMODULE hHandle = LoadLibrary("kernel32.dll");

// Reserve the virtual memory.
lpVirt = (LPVIRT)GetProcAddress(hHandle, "VirtualAlloc");
lpMemReserved = (*lpVirt)( NULL,m_uMBytes*0x100000,MEM_RESERVE | MEM_PHYSICAL,PAGE_READWRITE );

if( lpMemReserved == NULL )
{
TRACE("Cannot reserve memory.\n");
return;
}
*****
With 2.96 GB, shouldn't I be able to reserve more than 1100 MB? How can I do it?

Re: Trouble with VirtualAlloc

Luc Pattyn24-Aug-10 9:24

Luc Pattyn

24-Aug-10 9:24

Hi,

1.
please use PRE tags when showing code snippets, as it improves readability.

2.
on 32-bit Windows, the user part of the virtual address space is limited to 2GB (per process). There is a way to extend that to 3GB, use Google to locate it. I have the impression you didn't do it, since you didn't mention it at all. On 64-bit Windows, the situation obviously is quite different.

3.
within 2GB virtual space, I'm not very surprised you get only some 1.1GB; as your own code and data is in that same 2GB space. I don't know what the default addresses for those would be; a link map should contain all such info. Have a look at the linker switches and ask for a map; then maybe look for more switches if you want to alter the virtual addresses used by code and data.

4.
I haven't used MEM_PHYSICAL yet, and haven't read up on all the doc, however I would be concerned it may also imply you are asking for contiguous physical memory (mind you, I'm not sure here). Finding such amount of contiguous memory is pretty unlikely.

5.
Maybe you should tell a bit about the overall goals; just maybe there is a better approach for what you are after.

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, and improve readability.

Re: Trouble with VirtualAlloc

garyflet24-Aug-10 10:08

garyflet

24-Aug-10 10:08

Thank you very much for your prompt reply. My overall goal is to be able to have my application access memory beyond the 2GB boundary so that it can allocate physical memory beyond the 2GB boundary and I am able to allocate 2 to 3 (maybe more?) GBs of memory. One solution you mentioned (the 3GB extension) is described here:

http://msdn.microsoft.com/en-us/library/ms189334(SQL.100).aspx

This solution however affects the allocation of memory for every application on the system, and is not something I really want to do. I just want my particular application to be able to allocate beyond the boundary.

Note that the link above mentions AWE, which I am trying to use. Note that the diagram shows the that memory allocated in physical memory is not contiguous, which addresses your concern. The link posted in my first post is the code I am using to use AWE. As I mentioned, the only difference is that I'm using LoadLibrary to access the allocation and mapping functions. This link discusses AWE in more detail:

http://msdn.microsoft.com/en-us/library/aa366527(VS.85).aspx

Included in description for the AWE functions in the documentation is the following: "Physical pages can reside at any physical address. You should make no assumptions about the contiguity of the physical pages."

So the hitch at this point to making this work is VirtualAlloc(). The previous function in the example, "AllocateUserPhysicalPages()" works fine.

Re: Trouble with VirtualAlloc

Luc Pattyn24-Aug-10 10:15

Luc Pattyn

24-Aug-10 10:15

OK, I haven't thought this through yet, however I have one more suggestion:

put your code in a loop, i.e. try allocating the largest you can get, display the size (and address), do not release it, and repeat this all over and over and over. You might be getting a number of probably decreasing chunks, and the sum of those sizes (and maybe addresses) could tell you something interesting.

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, and improve readability.

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