C / C++ / MFC

Re: how does an app know user selection in Explore?

7-Apr-05 17:20

Only Windows explorer in the moment.
I will test your code, thanks.

includeh10

Sheng Jiang 蒋晟8-Apr-05 2:33

Sheng Jiang 蒋晟

8-Apr-05 2:33

IE looks like Explorer when it is showing a folder view

http://blog.joycode.com/jiangsheng
http://blog.csdn.net/jiangsheng
Command what is yours
Conquer what is not
---Kane

Re: how does an app know user selection in Explore?

includeh107-Apr-05 18:18

Re: how does an app know user selection in Explore?

7-Apr-05 18:18

HWND hWnd=::FindWindow("ExploreWClass",0); is not working.

it may work on win95 only according to MSDN.

any more comments?

includeh10

David Crow8-Apr-05 2:43

search order of DOS execution

8-Apr-05 2:43

includeh10 wrote:
HWND hWnd=::FindWindow("ExploreWClass",0); is not working.

Which means nothing unless you explain what "not working" means. Do you get a compiler/linker error? Does it fail to find a window with the indicated class name?

includeh10 wrote:
it may work on win95 only according to MSDN.

You need to re-read it again. The FindWindow() function is supported on Windows NT 3.1 and later, and Windows 95 and later.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

includeh107-Apr-05 6:30

7-Apr-05 6:30

when we type a command on DOS window to execute a exe file, i.e.
regedit.exe

OS actually searches from a set of directories, if the file is not found, it shows error.

Do you know full list and searchong order of these directories?

thanks

includeh10

David Crow7-Apr-05 6:51

7-Apr-05 6:51

Per MSDN:

If the file name does not contain a directory path, the system searches for the executable file in the following sequence:

1) The directory from which the application loaded.
2) The current directory for the parent process.
3) Windows 95/98/Me: The Windows system directory. Use the GetSystemDirectory function to get the path of this directory.
Windows NT/2000/XP: The 32-bit Windows system directory. Use the GetSystemDirectory function to get the path of this directory. The name of this directory is System32.
4) Windows NT/2000/XP: The 16-bit Windows system directory. There is no function that obtains the path of this directory, but it is searched. The name of this directory is System.
5) The Windows directory. Use the GetWindowsDirectory function to get the path of this directory.
6) The directories that are listed in the PATH environment variable.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

includeh107-Apr-05 7:20

7-Apr-05 7:20

Hi DavidCrow,
thanks for extra info.
did you copy the info from MSDN?

two things need to know:
1. how to get "The directories that are listed in the PATH environment variable"?
2. "The current directory for the parent process" - what does it mean?

includeh10

David Crow7-Apr-05 7:57

7-Apr-05 7:57

includeh10 wrote:
did you copy the info from MSDN?

Yes, see this function, about 1/3 of the way down.

includeh10 wrote:
1. how to get "The directories that are listed in the PATH environment variable"?

To get the contents of any environment variable, use GetEnvironmentVariable().

includeh10 wrote:
2. "The current directory for the parent process" - what does it mean?

Exactly what it says.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

includeh107-Apr-05 17:42

How do you execute a file in memory, is it even possible...

7-Apr-05 17:42

if for CreateProcess() ...
lets say:
c:\dir0\parent.exe and child.exe

CreateProcess(NULL,"child.exe",...) is called by parent.exe

1)The directory from which the application loaded.
2)The current directory for the parent process.

the 1) is c:\dir0 definitely.
the 2) should be c:\dir0 also, right?

my understanding is that 1) and 2) are the same.

includeh10

Jabish7-Apr-05 6:08

Jabish

7-Apr-05 6:08

You know how you make an installer by packing a file under a
file then a footer under that.

When you use the file it uses the top file, so you make the top file read the footer to get the file sizes, read them into a buffer and write them out...

Well i was planing on using that same method to pack things like programs that are just dialogs under it, and have my program, (rather than write it to a file, and erase it afterwords, just execute it out of memory)... I could just make child windows, but this seems easyer to me, and i'm also mainly curious if it is really possile to do this...

Re: How do you execute a file in memory, is it even possible...

David Crow7-Apr-05 6:55

Re: How do you execute a file in memory, is it even possible...

7-Apr-05 6:55

Jabish wrote:
...rather than write it to a file, and erase it afterwords, just execute it out of memory...

This question has been asked several times in the past. Search CP for "PE file format."

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Michael Dunn7-Apr-05 7:19

Michael Dunn

7-Apr-05 7:19

You cannot run a file "from memory" because processes have separate address spaces. How would the new process read its code from yours?
Also, the OS uses memory-mapped files to load a binary into memory, which requires that the binary be a disk file.

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

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Re: How do you execute a file in memory, is it even possible...

LighthouseJ7-Apr-05 12:45

LighthouseJ

7-Apr-05 12:45

Can't you use malloc and get a chunk of memory big enough to hold the binary program, then manually load it from disk to memory? Next, use _beginthread/_beginthreadex and point it to the start of the memory you allocated? I know this probably isn't all you need to do, but that's what I'm thinking in a broadstroke. This wouldn't be it's own process either, it'll be a thread running under the guys process too.

Thank You...

Jabish7-Apr-05 13:21

Jabish

7-Apr-05 13:21

Thank (all of you)... Just got back on so sorry i diddn't thank all of you earler.

Just wondering about the "PE file format" is it that PE projector thing?

also do I have to use any special way of reading the file to a buffer, or can I do it the way I always do:

<br />
FILE *in;<br />
<br />
long size;<br />
char *Buffer;<br />
<br />
if(in = fopen("[blah]", "rb"))<br />
 {<br />
  fseek(in, 0, SEEK_END);<br />
   size = ftell(in);<br />
   Buffer = (char *) malloc(size);<br />
  fseek(in, 0, SEEK_SET);<br />
<br />
   fread(Buffer, 1, size, in);<br />
<br />
  fclose(in);<br />
 }<br />

----------
and then do the PE thing, or do i need to use ReadFile() or something...

If possible a specific code example would be appreicated, (haven't tried anything like this before) just a little confused.

PS:

wasn't planning on using this idea for a child window type deal... I was thinking more on the line of something like:

a patcher like there is before you log on to a game, after the patcher got it's files it could unpack and execute parts of the game, or the game could just unpack the patcher... that kind of thing. I don't actually NEED this, am just curious about it. Thanks again =8^)... please don't steal face... Sniff | :^)

Re: Thank You...

David Crow7-Apr-05 16:31

AfxBeginThread() ???????????

7-Apr-05 16:31

Jabish wrote:
Just wondering about the "PE file format" is it that PE projector thing

The example that I have seen, and may still have on my disk at work, requires knowledge of the Portable Executable file format.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Static(x)7-Apr-05 5:43

Static(x)

7-Apr-05 5:43

Hi everybody, i am using a simple thread in my program,
when i launch the thread it works , but slows my machine,
in the task manager the CPU usage is 100% until the thread is ended. I am using simple AfxBEginThread(..) function ,is there any other way to make thread work , without slowing down my PC???

With Best Regards

m0n0

David Crow7-Apr-05 6:54

7-Apr-05 6:54

The mere existence of a secondary thread will not cause the CPU usage to jump to 100%. You are doing something in this thread to cause that. Without seeing your code, it's impossible to say.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Joel Holdsworth7-Apr-05 6:57

Joel Holdsworth

7-Apr-05 6:57

Well... The AfxBeginThread function will simple create a thread to do work on the controller function you specify. So the CPU usage is down to what's in the function you write. If you write a function which crunches numbers in a loop or whatver, then your CPU usage will go to 100% while the function keeps crunching. However, if you only need to run a calculation intermittently try using Sleep(100), or CEvents to put the thread into suspended animation giving the rest of the threads time to do their jobs.

What are you trying to do with your worker thread?

Joel Holdsworth

Wanna give me a job this summer?
Check out my online CV and project history[^]

Static(x)7-Apr-05 7:54

Static(x)

7-Apr-05 7:54

"What are you trying to do with your worker thread?"

Pretty Lot, i am testing huge numbers(100 or more digits )
on primality.
Actually i am doing lots of operations there,probably this makes my cpu go 100% , anyway thanks for attention to all Smile | :)

m0n0

How does the process create threads?

LighthouseJ7-Apr-05 16:04

LighthouseJ

7-Apr-05 16:04

Change your priority to THREAD_PRIORITY_IDLE instead of the default which is normal. That'll lower the thread priority so it won't take your system with it. The command would be:

CWinThread * threadptr = AfxBeginThread(
pfnThreadProc,            // thread function
pParam,                   // pointer to data to use
THREAD_PRIORITY_IDLE,     // the idle priority, was THREAD_PRIORITY_NORMAL
0,                        // stack size, 0 means default size
0,                        // create and run immediately, don't suspend on creation
NULL                      // no security attributes
);

VC++.Net - Debugging XLL

JSadleir7-Apr-05 3:20

JSadleir

7-Apr-05 3:20

I have written an xll with basic arithmetical calculations. I want to use the debugger to step through those functions to confirm they are working properly. I have tried to do this by setting Excel as the Command application and a spreadsheet that loads the xll as the Command argument. I then place breakpoints throughout the functions. Unfortunately, the VC++.Net debugger never recognises the breakpoints (the warning glyph ? breakpoint appears). The two error messages are firstly:

"Excel.exe does not contain debugging information. (No symbols loaded.) Click OK to debug anyway"

Secondly:

"The following breakpoint cannot be set: When 'double' changes
Data breakpoints are not supported in the Common Language Runtime"

Is the only way to debug an xll/dll to create a separate basic application to call the xll function? Ideally I would want to be able to call from Excel so that I know exactly what Excel is feeding to the xll function parameters. Any thoughts you may have would be appreciated.

Regards

Jeremy

binh.pham7-Apr-05 3:20

binh.pham

7-Apr-05 3:20

Could anyone describe me how the process creates threads? I learned that there always exists a primary thread created as soon as the process gets started, but from then, how can we know how many threads are created? and when? and how can we know? can we take control of them?(I don't mention the threads created manually by me on using CreateThread, AfxBeginThread)
Regards.

Grenouille

Re: How does the process create threads?

toxcct7-Apr-05 3:33

toxcct

7-Apr-05 3:33

well, if you call once AfxBeginThread(), i believe you have only one thread...

TOXCCT >>> GEII power
[toxcct][VisualCalc]

Re: How does the process create threads?

David Crow7-Apr-05 4:46