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IStream interface

Hi all,

I am developing website application in asp.net , visual C# and atl com. I
am using atl com component in visual C# application. One of the function of
com component interface returns IStream interface.

I want to read data from that IStream interface. I am new to visual c#. I
have written some code. But, it is returning whole data. It is returning some
null characters.

I have checked same com dll with vc++ client. It is returning whole data
properly.

VC++ code snippet (client):
//pI is com interface in vc++ client
IStream* pStream = NULL;
pI->TestStream(&pS tream);
char* str1 = new char[30720];
ULONG rval = 0;
LARGE_INTEGER liBeggining = { 0 };
pStream->Seek(liBeggini ng,STREAM_SEEK_ SET, NULL);
STATSTG statstg;
memset (&statstg, 0, sizeof(statstg) );
hr = pStream -Stat(&statstg, STATFLAG_NONAME );
pStream->Read(str1,3072 0,&rval);
pStream->Release();
int nFileHandle =
_open((LPCSTR)" c:\\atlcomdll\\ chk1.txt",_O_CR EAT|_O_BINARY|_ O_RDWR|_O_TRUNC ,_S_IREAD | _S_IWRITE);
_write(nFileHan dle,str1,30720) ;
_close(nFileHan dle);

delete[] str1;
Visual c# code snippet:

IStream pStream = null;
obj.TestStream( ref pStream);
tagSTATSTG statstg = new tagSTATSTG();
_LARGE_INTEGER liBeggining ;
liBeggining.Qua dPart = 0;
_ULARGE_INTEGER newpos ;
newpos.QuadPart = 0;
pStream.RemoteS eek(liBeggining , 0, out newpos);
uint x = 0;
pStream.Stat(ou t statstg,x);
byte[] mybytearray = new byte[30720];
uint xy;
for (uint i = 0; i < 30720; i ++)
{
uint yz = 0;
pStream.RemoteR ead(out mybytearray[i], i, out yz);
}

System.IO.FileS tream objGetInfo =
System.IO.File. Create("C:\\ATL COMDLL\\hi.txt" );
objGetInfo.Writ e(mybytearray, 0, 30720);
objGetInfo.Clos e();
Now, I am comparing with chk1.txt and hi.txt. But, both are not same.

How to get the whole data in byte[] in visual c# using IStream interface?

suggest me.
--
Thanks & Regards,
John.
May 11 '07 #1
4 4473
"John" <Jo**@discussio ns.microsoft.co mwrote in message
news:2E******** *************** ***********@mic rosoft.com...
Hi all,

I am developing website application in asp.net , visual C# and atl com.
I
am using atl com component in visual C# application. One of the function
of
com component interface returns IStream interface.

I want to read data from that IStream interface. I am new to visual c#. I
have written some code. But, it is returning whole data. It is returning
some
null characters.

I have checked same com dll with vc++ client. It is returning whole data
properly.

VC++ code snippet (client):
//pI is com interface in vc++ client
IStream* pStream = NULL;
pI->TestStream(&pS tream);
char* str1 = new char[30720];
ULONG rval = 0;
LARGE_INTEGER liBeggining = { 0 };
pStream->Seek(liBeggini ng,STREAM_SEEK_ SET, NULL);
STATSTG statstg;
memset (&statstg, 0, sizeof(statstg) );
hr = pStream -Stat(&statstg, STATFLAG_NONAME );
pStream->Read(str1,3072 0,&rval);
pStream->Release();
int nFileHandle =
_open((LPCSTR)" c:\\atlcomdll\\ chk1.txt",_O_CR EAT|_O_BINARY|_ O_RDWR|_O_TRUNC ,_S_IREAD
| _S_IWRITE);
_write(nFileHan dle,str1,30720) ;
_close(nFileHan dle);

delete[] str1;
Visual c# code snippet:

IStream pStream = null;
obj.TestStream( ref pStream);
tagSTATSTG statstg = new tagSTATSTG();
_LARGE_INTEGER liBeggining ;
liBeggining.Qua dPart = 0;
_ULARGE_INTEGER newpos ;
newpos.QuadPart = 0;
pStream.RemoteS eek(liBeggining , 0, out newpos);
uint x = 0;
pStream.Stat(ou t statstg,x);
byte[] mybytearray = new byte[30720];
uint xy;
for (uint i = 0; i < 30720; i ++)
{
uint yz = 0;
pStream.RemoteR ead(out mybytearray[i], i, out yz);
}

System.IO.FileS tream objGetInfo =
System.IO.File. Create("C:\\ATL COMDLL\\hi.txt" );
objGetInfo.Writ e(mybytearray, 0, 30720);
objGetInfo.Clos e();
Now, I am comparing with chk1.txt and hi.txt. But, both are not same.

How to get the whole data in byte[] in visual c# using IStream interface?

suggest me.
--
Thanks & Regards,
John.

Do you actually understand what you are doing here?

for (uint i = 0; i < 30720; i ++)
{
uint yz = 0;
pStream.RemoteR ead(out mybytearray[i], i, out yz);
}
you are overwriting the buffer for each iteration, with a decreasing number
of bytes from the stream ...
You should read the whole stream at once just like you did in C++:

uint yz = 0;
pStream.RemoteR ead(out mybytearray, sizeof(mybytear ray), out
yz);

and check the number of bytes returned (yz) in the buffer against the size
of the buffer, if yz is smaller, then you are done reading, if equal you may
have more data to read...

Note that I can't comment on the remaining part of the code, as it's
incomplete, but there may be other issues.
Willy.

May 11 '07 #2
Hi Willy,

Thank you for your prompt response.

Is there any article to read the data from stream in visual c sharp
application for website.

I have replace with this below code according to your suggestion.
- uint xy;
pStream.RemoteR ead(out mybytearray, 30720, out xy);

the output is :
----- Build started: Project: http://localhost/server1_test/, Configuration:
Debug .NET ------
Validating Web Site
Building directory '/server1_test/'.

f:\inetpub\wwwr oot\server1_tes t\Default.aspx. cs(67,9): error CS1502: The
best overloaded method match for 'SERVER1Lib.ISt ream.RemoteRead (out byte,
uint, out uint)' has some invalid arguments
f:\inetpub\wwwr oot\server1_tes t\Default.aspx. cs(67,32): error CS1503:
Argument '1': cannot convert from 'out byte[]' to 'out byte'
Validation Complete
========== Build: 0 succeeded or up-to-date, 1 failed, 0 skipped ==========
It is not allowing to take byte[]. It accepts only byte.

How do I resolve this?
-
Thanks & Regards,
John.
"Willy Denoyette [MVP]" wrote:
"John" <Jo**@discussio ns.microsoft.co mwrote in message
news:2E******** *************** ***********@mic rosoft.com...
Hi all,

I am developing website application in asp.net , visual C# and atl com.
I
am using atl com component in visual C# application. One of the function
of
com component interface returns IStream interface.

I want to read data from that IStream interface. I am new to visual c#. I
have written some code. But, it is returning whole data. It is returning
some
null characters.

I have checked same com dll with vc++ client. It is returning whole data
properly.

VC++ code snippet (client):
//pI is com interface in vc++ client
IStream* pStream = NULL;
pI->TestStream(&pS tream);
char* str1 = new char[30720];
ULONG rval = 0;
LARGE_INTEGER liBeggining = { 0 };
pStream->Seek(liBeggini ng,STREAM_SEEK_ SET, NULL);
STATSTG statstg;
memset (&statstg, 0, sizeof(statstg) );
hr = pStream -Stat(&statstg, STATFLAG_NONAME );
pStream->Read(str1,3072 0,&rval);
pStream->Release();
int nFileHandle =
_open((LPCSTR)" c:\\atlcomdll\\ chk1.txt",_O_CR EAT|_O_BINARY|_ O_RDWR|_O_TRUNC ,_S_IREAD
| _S_IWRITE);
_write(nFileHan dle,str1,30720) ;
_close(nFileHan dle);

delete[] str1;
Visual c# code snippet:

IStream pStream = null;
obj.TestStream( ref pStream);
tagSTATSTG statstg = new tagSTATSTG();
_LARGE_INTEGER liBeggining ;
liBeggining.Qua dPart = 0;
_ULARGE_INTEGER newpos ;
newpos.QuadPart = 0;
pStream.RemoteS eek(liBeggining , 0, out newpos);
uint x = 0;
pStream.Stat(ou t statstg,x);
byte[] mybytearray = new byte[30720];
uint xy;
for (uint i = 0; i < 30720; i ++)
{
uint yz = 0;
pStream.RemoteR ead(out mybytearray[i], i, out yz);
}

System.IO.FileS tream objGetInfo =
System.IO.File. Create("C:\\ATL COMDLL\\hi.txt" );
objGetInfo.Writ e(mybytearray, 0, 30720);
objGetInfo.Clos e();
Now, I am comparing with chk1.txt and hi.txt. But, both are not same.

How to get the whole data in byte[] in visual c# using IStream interface?

suggest me.
--
Thanks & Regards,
John.


Do you actually understand what you are doing here?

for (uint i = 0; i < 30720; i ++)
{
uint yz = 0;
pStream.RemoteR ead(out mybytearray[i], i, out yz);
}
you are overwriting the buffer for each iteration, with a decreasing number
of bytes from the stream ...
You should read the whole stream at once just like you did in C++:

uint yz = 0;
pStream.RemoteR ead(out mybytearray, sizeof(mybytear ray), out
yz);

and check the number of bytes returned (yz) in the buffer against the size
of the buffer, if yz is smaller, then you are done reading, if equal you may
have more data to read...

Note that I can't comment on the remaining part of the code, as it's
incomplete, but there may be other issues.
Willy.


May 12 '07 #3
"John" <Jo**@discussio ns.microsoft.co mwrote in message
news:C4******** *************** ***********@mic rosoft.com...
Hi Willy,

Thank you for your prompt response.

Is there any article to read the data from stream in visual c sharp
application for website.

I have replace with this below code according to your suggestion.
- uint xy;
pStream.RemoteR ead(out mybytearray, 30720, out xy);

the output is :
----- Build started: Project: http://localhost/server1_test/,
Configuration:
Debug .NET ------
Validating Web Site
Building directory '/server1_test/'.

f:\inetpub\wwwr oot\server1_tes t\Default.aspx. cs(67,9): error CS1502: The
best overloaded method match for 'SERVER1Lib.ISt ream.RemoteRead (out byte,
uint, out uint)' has some invalid arguments
f:\inetpub\wwwr oot\server1_tes t\Default.aspx. cs(67,32): error CS1503:
Argument '1': cannot convert from 'out byte[]' to 'out byte'
Validation Complete
========== Build: 0 succeeded or up-to-date, 1 failed, 0 skipped
==========
It is not allowing to take byte[]. It accepts only byte.

How do I resolve this?
-
Thanks & Regards,
John.


As I told you it's hard to answer such questions if you only post a part of
the code, what I'm missing here is your RemoteRead declaration.
Anyway, try this:

pStream.RemoteR ead(mybytearray , 30720, out xy);

Also, don't use hard coded values, pass the size of the byte[] like this:

pStream.RemoteR ead(mybytearray , mybytearray.Len gth, out xy);

and use meaningfull and "correctly" cased names in your code....

pStream.RemoteR ead(myByteArray , myByteArray.Len gth, out bytesReturned);

Willy.
May 12 '07 #4
"John" <Jo**@discussio ns.microsoft.co mwrote in message
news:C4******** *************** ***********@mic rosoft.com...
Hi Willy,

Thank you for your prompt response.

Is there any article to read the data from stream in visual c sharp
application for website.

I have replace with this below code according to your suggestion.
- uint xy;
pStream.RemoteR ead(out mybytearray, 30720, out xy);

the output is :
----- Build started: Project: http://localhost/server1_test/,
Configuration:
Debug .NET ------
Validating Web Site
Building directory '/server1_test/'.

f:\inetpub\wwwr oot\server1_tes t\Default.aspx. cs(67,9): error CS1502: The
best overloaded method match for 'SERVER1Lib.ISt ream.RemoteRead (out byte,
uint, out uint)' has some invalid arguments
f:\inetpub\wwwr oot\server1_tes t\Default.aspx. cs(67,32): error CS1503:
Argument '1': cannot convert from 'out byte[]' to 'out byte'
Validation Complete
========== Build: 0 succeeded or up-to-date, 1 failed, 0 skipped
==========
It is not allowing to take byte[]. It accepts only byte.

How do I resolve this?
-
Thanks & Regards,
John.
"Willy Denoyette [MVP]" wrote:
>"John" <Jo**@discussio ns.microsoft.co mwrote in message
news:2E******* *************** ************@mi crosoft.com...
Hi all,

I am developing website application in asp.net , visual C# and atl
com.
I
am using atl com component in visual C# application. One of the
function
of
com component interface returns IStream interface.

I want to read data from that IStream interface. I am new to visual
c#. I
have written some code. But, it is returning whole data. It is
returning
some
null characters.

I have checked same com dll with vc++ client. It is returning whole
data
properly.

VC++ code snippet (client):
//pI is com interface in vc++ client
IStream* pStream = NULL;
pI->TestStream(&pS tream);
char* str1 = new char[30720];
ULONG rval = 0;
LARGE_INTEGER liBeggining = { 0 };
pStream->Seek(liBeggini ng,STREAM_SEEK_ SET, NULL);
STATSTG statstg;
memset (&statstg, 0, sizeof(statstg) );
hr = pStream -Stat(&statstg, STATFLAG_NONAME );
pStream->Read(str1,3072 0,&rval);
pStream->Release();
int nFileHandle =
_open((LPCSTR)" c:\\atlcomdll\\ chk1.txt",_O_CR EAT|_O_BINARY|_ O_RDWR|_O_TRUNC ,_S_IREAD
| _S_IWRITE);
_write(nFileHan dle,str1,30720) ;
_close(nFileHan dle);

delete[] str1;
Visual c# code snippet:

IStream pStream = null;
obj.TestStream( ref pStream);
tagSTATSTG statstg = new tagSTATSTG();
_LARGE_INTEGER liBeggining ;
liBeggining.Qua dPart = 0;
_ULARGE_INTEGER newpos ;
newpos.QuadPart = 0;
pStream.RemoteS eek(liBeggining , 0, out newpos);
uint x = 0;
pStream.Stat(ou t statstg,x);
byte[] mybytearray = new byte[30720];
uint xy;
for (uint i = 0; i < 30720; i ++)
{
uint yz = 0;
pStream.RemoteR ead(out mybytearray[i], i, out yz);
}

System.IO.FileS tream objGetInfo =
System.IO.File. Create("C:\\ATL COMDLL\\hi.txt" );
objGetInfo.Writ e(mybytearray, 0, 30720);
objGetInfo.Clos e();
Now, I am comparing with chk1.txt and hi.txt. But, both are not same.

How to get the whole data in byte[] in visual c# using IStream
interface?

suggest me.
--
Thanks & Regards,
John.


Do you actually understand what you are doing here?

for (uint i = 0; i < 30720; i ++)
{
uint yz = 0;
pStream.RemoteR ead(out mybytearray[i], i, out yz);
}
you are overwriting the buffer for each iteration, with a decreasing
number
of bytes from the stream ...
You should read the whole stream at once just like you did in C++:

uint yz = 0;
pStream.RemoteR ead(out mybytearray, sizeof(mybytear ray), out
yz);

and check the number of bytes returned (yz) in the buffer against the
size
of the buffer, if yz is smaller, then you are done reading, if equal you
may
have more data to read...

Note that I can't comment on the remaining part of the code, as it's
incomplete, but there may be other issues.
Willy.



May 12 '07 #5

This thread has been closed and replies have been disabled. Please start a new discussion.

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