How to convert a Byte array to a char array?

[Kueishiong Tu]

How do I convert a Byte array (unsigned char managed) to a
char array(unmanaged ) with wide character taken into
account?

[Nishant S]

Byte barray[] = new Byte[512];
__wchar_t* arr = new __wchar_t[barray->Length];
for(int i=0; i < barray->Length; i++)
arr[i] = barray[i];
delete arr;

--
Regards,
Nish [VC++ MVP]

"Kueishiong Tu" <ks****@seed.ne t.tw> wrote in message
news:2d******** *************** *****@phx.gbl.. .

How do I convert a Byte array (unsigned char managed) to a
char array(unmanaged ) with wide character taken into
account?

[Kueishiong Tu]

-----Original Message-----
Byte barray[] = new Byte[512];
__wchar_t* arr = new __wchar_t[barray->Length];
for(int i=0; i < barray->Length; i++)
arr[i] = barray[i];
delete arr;

How do I further convert to a array declared as char
carray[]? The access of a char array through its pointer
has taken the wide character into account. i.e., if

char *cpp;
int n;
cpp = carray;

(cpp+n) will always point to a valid wide charater (n any
int).

[Nishant S]

Byte barray[] = new Byte[512];

//char here is 16 bits
char smallarray[512];
for(int i=0; i<barray->Length; i++)
smallarray[i] = barray[i];

//Char here is 32 bits
Char carray[] = Encoding::ASCII->GetChars(barra y);
--
Regards,
Nish [VC++ MVP]

"Kueishiong Tu" <ks****@seed.ne t.tw> wrote in message
news:2f******** *************** *****@phx.gbl.. .

-----Original Message-----
Byte barray[] = new Byte[512];
__wchar_t* arr = new __wchar_t[barray->Length];
for(int i=0; i < barray->Length; i++)
arr[i] = barray[i];
delete arr;

How do I further convert to a array declared as char
carray[]? The access of a char array through its pointer
has taken the wide character into account. i.e., if

char *cpp;
int n;
cpp = carray;

(cpp+n) will always point to a valid wide charater (n any
int).

[Kueishiong Tu]

-----Original Message-----
Byte barray[] = new Byte[512];

//char here is 16 bits
char smallarray[512];
for(int i=0; i<barray->Length; i++)
smallarray[i] = barray[i];

//Char here is 32 bits
Char carray[] = Encoding::ASCII->GetChars(barra y);

The byte array contains a mixture of
raw data of Ascii (8-bit) and Chinese characters (16-bit).
What I need is to convert the byte array into a char array
so that if I assigned a char pointer to the beginning of
the char array and I increment the char pointer, it will
point to a valid wide character which may be 8-bit or 16-
bit.

Byte barray[512];
char carray[512];
char *cpp;
//convert barray to caaray
cpp = carray;
printf("%c\n", *cpp); // valid 8-bit or 16-bit character
*(cpp++);
printf("%c\n", *cpp); // valid 8-bit or 16-bit character
*(cpp++);
printf("%c\n", *cpp); // valid 8-bit or 16-bit character
*(cpp++);
printf("%c\n", *cpp); // valid 8-bit or 16-bit character
*(cpp++);
printf("%c\n", *cpp); // valid 8-bit or 16-bit character
*(cpp++);
printf("%c\n", *cpp); // valid 8-bit or 16-bit character
*(cpp++);

and so on ....

[Jochen Kalmbach]

Kueishiong Tu wrote:

How do I convert a Byte array (unsigned char managed) to a
char array(unmanaged ) with wide character taken into
account?

See: StringToHGlobal Ansi (System::Runtim e::InteropServi ces::Marshal)
http://msdn.microsoft.com/library/en-
us/cpref/html/frlrfsystemrunt imeinteropservi cesmarshalclass stringtohglobal a
nsitopic.asp

But conversion to ANSI is bad... because String is UNICODE... so if it
contains some unicode characters this might be lost.

Better convert to unicde: StringToHGlobal Uni
or use PtrToStringChar s (which is faster; if you do not need to modify the
string)

See also:
HOW TO: Convert from System::String* to Char* in Visual C++ .NET
http://support.microsoft.com/?kbid=311259

--
Greetings
Jochen

Do you need a memory-leak finder ?
http://www.codeproject.com/tools/leakfinder.asp

[Nishant S]

There was en error in my prev post.

char is 8 bits (a byte) and Char is 16 bits (2 bytes)

--
Regards,
Nish [VC++ MVP]

"Nishant S" <ni**@nospam.as ianetindia.com> wrote in message
news:up******** ******@tk2msftn gp13.phx.gbl...

Byte barray[] = new Byte[512];

//char here is 16 bits
char smallarray[512];
for(int i=0; i<barray->Length; i++)
smallarray[i] = barray[i];

//Char here is 32 bits
Char carray[] = Encoding::ASCII->GetChars(barra y);
--
Regards,
Nish [VC++ MVP]

"Kueishiong Tu" <ks****@seed.ne t.tw> wrote in message
news:2f******** *************** *****@phx.gbl.. .

-----Original Message-----
Byte barray[] = new Byte[512];
__wchar_t* arr = new __wchar_t[barray->Length];
for(int i=0; i < barray->Length; i++)
arr[i] = barray[i];
delete arr;

How do I further convert to a array declared as char
carray[]? The access of a char array through its pointer
has taken the wide character into account. i.e., if

char *cpp;
int n;
cpp = carray;

(cpp+n) will always point to a valid wide charater (n any
int).

[Nishant S]

If you have Chinese characters then you cannot use a char array because a
char is only 8 bits. You need to use a Char (System::Char) or a __whcar_t
then.

BTW considering that a Byte is 8 bits I wonder how you can store chinese
characters in a Byte array unless you have a random kinda layout where
depending on whether the character you want to store is unicode or not, you
allot either one byte or two bytes for storing a character. Not a very
organized approach in my opinion.

--
Regards,
Nish [VC++ MVP]

"Kueishiong Tu" <ks****@seed.ne t.tw> wrote in message
news:3b******** *************** *****@phx.gbl.. .

-----Original Message-----
Byte barray[] = new Byte[512];

//char here is 16 bits
char smallarray[512];
for(int i=0; i<barray->Length; i++)
smallarray[i] = barray[i];

//Char here is 32 bits
Char carray[] = Encoding::ASCII->GetChars(barra y);

The byte array contains a mixture of
raw data of Ascii (8-bit) and Chinese characters (16-bit).
What I need is to convert the byte array into a char array
so that if I assigned a char pointer to the beginning of
the char array and I increment the char pointer, it will
point to a valid wide character which may be 8-bit or 16-
bit.

Byte barray[512];
char carray[512];
char *cpp;
//convert barray to caaray
cpp = carray;
printf("%c\n", *cpp); // valid 8-bit or 16-bit character
*(cpp++);
printf("%c\n", *cpp); // valid 8-bit or 16-bit character
*(cpp++);
printf("%c\n", *cpp); // valid 8-bit or 16-bit character
*(cpp++);
printf("%c\n", *cpp); // valid 8-bit or 16-bit character
*(cpp++);
printf("%c\n", *cpp); // valid 8-bit or 16-bit character
*(cpp++);
printf("%c\n", *cpp); // valid 8-bit or 16-bit character
*(cpp++);

and so on ....

[Kueishiong Tu]

-----Original Message-----
If you have Chinese characters then you cannot use a char array because achar is only 8 bits. You need to use a Char (System::Char) or a __whcar_tthen.

BTW considering that a Byte is 8 bits I wonder how you can store chinesecharacters in a Byte array unless you have a random kinda layout wheredepending on whether the character you want to store is unicode or not, youallot either one byte or two bytes for storing a character. Not a veryorganized approach in my opinion.

--
Regards,
Nish [VC++ MVP]

The Byte array I got is from a Webclient::Uplo adData call
which put the data returned in a Byte array (which may
contain both one byte Ascii and two-byte Chinese Big-5
code). VC++ can handle char array which may store both
one-byte ascii and two=byte Big-5 characters. I have
several functions which work fine with this situation.
The problem is how to convert the Byte array to a char
array so I have use a char porinter to decode the message
one character at a time.

[Nishant S]

Hmmm

Okay I think one of the following is what you want :-

//this is to obtain a single byte char array
//might lose chinese characters

char smallarray[512];
for(int i=0; i<barray->Length; i++)
smallarray[i] = barray[i];

//this gets a wide char array
String* tmp = new String(Encoding ::ASCII->GetChars(barra y));
__wchar_t* array = (__wchar_t*)Mar shal::StringToH GlobalUni(
tmp).ToPointer( );
//...
// You can now use array (wide char array)
//...
Marshal::FreeCo TaskMem(array);

I think the second one is what you want. Please try it out and see if it
works for you.

--
Regards,
Nish [VC++ MVP]

"Kueishiong Tu" <ks****@seed.ne t.tw> wrote in message
news:30******** *************** *****@phx.gbl.. .

-----Original Message-----
If you have Chinese characters then you cannot use a

char array because a

char is only 8 bits. You need to use a Char

(System::Char) or a __whcar_t

then.

BTW considering that a Byte is 8 bits I wonder how you

can store chinese

characters in a Byte array unless you have a random

kinda layout where

depending on whether the character you want to store is

unicode or not, you

allot either one byte or two bytes for storing a

character. Not a very

organized approach in my opinion.

--
Regards,
Nish [VC++ MVP]

The Byte array I got is from a Webclient::Uplo adData call
which put the data returned in a Byte array (which may
contain both one byte Ascii and two-byte Chinese Big-5
code). VC++ can handle char array which may store both
one-byte ascii and two=byte Big-5 characters. I have
several functions which work fine with this situation.
The problem is how to convert the Byte array to a char
array so I have use a char porinter to decode the message
one character at a time.