Re: Another cast problem - C / C++ / MFC Discussion Boards

Mazdak2-Mar-04 0:46

2-Mar-04 0:46

I want to convert a char * to unsigned char[](or fill that array with char * string) but I can't find it, I can do reverse of it but not this one.

Mazy

"A bank is a place that will lend you money if you can prove that you don't need it." - Bob Hope

Re: Another cast problem

Prakash Nadar2-Mar-04 0:51

Prakash Nadar

2-Mar-04 0:51

It will be helpfull with little bit of code that you are trying to convert.

char *pszString;
pszString = new char[20];

now pszString can store upto 19 bytes of string.
you can either access it as
pszstring,
if you want to access each char then
*(pszString+index)
or
pszString[index]

hope i answered ur question properly.

Re: Another cast problem

Rickard Andersson²⁰2-Mar-04 1:22

Rickard Andersson²⁰

2-Mar-04 1:22

Mr.Prakash wrote:
now pszString can store upto 19 bytes of string.

WRONG!
You allocated 20, right? How can you say it can hold 19 bytes then?
You know, it is starting from 0, that means 0 is the first element.

Rickard Andersson
Here is my card, contact me later!
UIN: 50302279
Sonork: 37318

Re: Another cast problem

Prakash Nadar2-Mar-04 1:28

Prakash Nadar

2-Mar-04 1:28

i allocated 20 bytes, 19 bytes for some string and the 20th for \0

Re: Another cast problem

David Crow2-Mar-04 7:43

David Crow

2-Mar-04 7:43

But ASCII 0 is still a valid character, it just happens to be a special one. Allocating 20 bytes on the heap means you can store 20 bytes.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Another cast problem

Prakash Nadar2-Mar-04 13:16

Prakash Nadar

2-Mar-04 13:16

DavidCrow wrote:
Allocating 20 bytes on the heap means you can store 20 bytes.

yep but you cant store 20 'A's

Re: Another cast problem

David Crow3-Mar-04 2:23

David Crow

3-Mar-04 2:23

Of course not. I was simply saying that your "now pszString can store upto 19 bytes of string" comment was off by one.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Another cast problem

Mazdak2-Mar-04 1:27

Mazdak

2-Mar-04 1:27

Thanks for reply, I have a problem now, see this code:

for(int i = 0 ; i < sizeof(mypointer);i++)
   buffer1[i] = *(val+i);

sizeof(mypointer) cause the loop only run 3 times and other chars do not copy to array , if I change it to a larger number like 200 it works ok but I don't know how to get size of it dynamiclly.

Mazy

"A bank is a place that will lend you money if you can prove that you don't need it." - Bob Hope

Re: Another cast problem

Rickard Andersson²⁰2-Mar-04 1:32

Rickard Andersson²⁰

2-Mar-04 1:32

Mazdak wrote:
sizeof(mypointer)

Change to:

strlen(mypointer)

When you do sizeof of a pointer it returns the size of the pointer, not the length of the string.

Rickard Andersson
Here is my card, contact me later!
UIN: 50302279
Sonork: 37318

Re: Another cast problem

Mazdak2-Mar-04 1:44

Mazdak

2-Mar-04 1:44

Thanks again Rickard. Smile | :)

Mazy

"A bank is a place that will lend you money if you can prove that you don't need it." - Bob Hope

Re: Another cast problem

Prakash Nadar2-Mar-04 1:34

Prakash Nadar

2-Mar-04 1:34

change it to this way.

for(int i = 0 ; *(val+i)!=NULL;i++)   
    buffer1[i] = *(val+i);

since pointers are always 4 bytes sizeof(anypointer) will always return 4

Re: Another cast problem

Prakash Nadar2-Mar-04 1:36

Prakash Nadar

2-Mar-04 1:36

Mazdak wrote:
but I don't know how to get size of it dynamiclly.

strlen will give you the size of the string pointed by the pointer.

Re: Another cast problem

Mazdak2-Mar-04 1:42

Mazdak

2-Mar-04 1:42

Thanks.

Mazy

"A bank is a place that will lend you money if you can prove that you don't need it." - Bob Hope

Re: Another cast problem

Rickard Andersson²⁰2-Mar-04 1:15

Rickard Andersson²⁰

2-Mar-04 1:15

If I understand you, you want to copy the data from a char* to a unsigned char[]?

char* p = "bla bla";
unsigned char uch[WHATEVER_SIZE];
strcpy(reinterpret_cast<char*>(uch), p);
cout << uch << endl;

Rickard Andersson
Here is my card, contact me later!
UIN: 50302279
Sonork: 37318

Re: Another cast problem

Mazdak2-Mar-04 1:30

Mazdak

2-Mar-04 1:30

Yah, thats what I want. Thanks.

Mazy

"A bank is a place that will lend you money if you can prove that you don't need it." - Bob Hope

Displaying an EMF file

Pazzuzu1-Mar-04 23:41

Pazzuzu

1-Mar-04 23:41

Hello,

I have an ".Emf" file on my harddisc,Which I would like to display to screen.
I used the "PlayEnhMetaFile" function for displaying the emf to screen,so far.But It has some problems displaying certain kind of EMF files.

Is there any other way by which I could display the Emf File other than using the "PlayEnhMetaFile" or "PlayMetaFile" functions.

Could any one show it with a piece of sample Code.

Thanks..

InstallShield commands?

Dov Sherman1-Mar-04 22:31

Dov Sherman

1-Mar-04 22:31

This isn't exactly VC++ but I'm having difficulty with the InstallShield that comes bundled with it so...

At the end of installation, in the "Finished" dialog, I want to give the user the option to display the readme file and launch the program. I know how to add those the text for those options and read the results of the user's selection but how do I actually perform those operations?

In the InstallShield script, how do you display a text file in Notepad and launch the installed software?

delete

vikramlinux1-Mar-04 21:23

vikramlinux

1-Mar-04 21:23

Anybody know how delete operator works over dynamically allocated 2-D array ? How is come to know about the bytes allocated ?

Vikram S

Re: delete

valikac2-Mar-04 5:36

valikac

2-Mar-04 5:36

The memory location is contiguous.

Kuphryn

Re: delete

vikramlinux2-Mar-04 17:12

vikramlinux

2-Mar-04 17:12

Yes, I meant generally arrays are allocated in continous memory locations.The issue is not that. How the delete operator comes to know about "How many bytes to be freed?"

Re: delete

valikac2-Mar-04 17:52

valikac

2-Mar-04 17:52

I would say it deallocates memory until there is a NULL.

Kuphryn

Re: delete

vikramlinux2-Mar-04 18:13

vikramlinux

2-Mar-04 18:13

hey in case of string it's quite okey. But what if i have array of intergers? and NULL =0 ?

Automate Enabling of DHCP

hollesome1-Mar-04 21:17

hollesome

1-Mar-04 21:17

can anyone help me regarding enabling dhcp automatically.
The program should change the network properties to obtain ip address dynamically.
I tried dhcpsvc and iphlpapi but i cant make it to work. anyone???

Thanks in advance.

Conrad

Re: Automate Enabling of DHCP

David Crow2-Mar-04 9:54

David Crow

2-Mar-04 9:54

To enable DHCP:

HKEY hKey;
DWORD dwEnable = 1;
RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SYSTEM\CurrentControlSet\Services\{5AE5DC8F-790F-4DA3-B5EF-492139A60ED7}\Parameters\Tcpip", 0, KEY_WRITE, &hKey);
RegSetValueEx(hKey, "EnableDHCP", 0, REG_DWORD, &dwEnable, sizeof(dwEnable));
const char szTemp[] = "0.0.0.0";
RegSetValueEx(hKey, "IPAddress", 0, REG_MULTI_SZ, (const BYTE *) szTemp, sizeof(szTemp) + 1);
RegSetValueEx(hKey, "SubnetMask", 0, REG_MULTI_SZ, (const BYTE *) szTemp, sizeof(szTemp) + 1);

The bold interface will need to be changed accordingly.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Automate Enabling of DHCP

hollesome2-Mar-04 14:55

hollesome

2-Mar-04 14:55

Thank you very much for the reply, after this how do i restart my network connection in order for the changes in the registry will take effect??

Another big thanks in advance.

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