Array of structures from a COM callback.

[Rich Claxton]

Hi we have a 3rd party in process com dll, which was written In C++ and our
client is in c#.

All is working fine apart from we get a callback from the DLL which contains
an array of structures.

The callback signature looks like this,

With the list stored in the radioSubscriber Attributes3List , which is defined
in the type library which was created when we imported the com dll into .net

unsafe private void GroupManager_Ge tRadioSubscribe rsConfirmation( uint
radioSubscriber Attributes3List Size, ref tcsRadioSubscri berAttributes3_ t
radioSubscriber Attributes3List , tcsBoolean_t endOfCollection , short cookie);

trouble is we only get the first structure back, if I use the code below.

tcsRadioSubscri berAttributes3_ t[] DATA = new
tcsRadioSubscri berAttributes3_ t[3];
temp = Marshal.AllocCo TaskMem(IntPtr. Size);
buffer = Marshal.AllocCo TaskMem(IntPtr. Size);

//get the address in buffer
Marshal.Structu reToPtr(radioSu bscriberAttribu tes3List, buffer, true);
temp = buffer;

for(int a=0; a<radioSubscrib erAttributes3Li stSize; a++ )
{
DATA[a] =
(tcsRadioSubscr iberAttributes3 _t)Marshal.PtrT oStructure(temp ,radioSubscribe rAttributes3Lis t.GetType());
temp = (IntPtr)((int)b uffer +
Marshal.SizeOf( radioSubscriber Attributes3List .GetType()));
}

I guess StructureToPtr copies the first item from the list passed to us,
into managed memory, and not the rest.

Any help, as if we don’t get this working we will have to write the client
in Delphi !!!!

Cheers Rich.

[Jianwei Sun]

Rich,

I cannot gurantee this is the right answer, but if I were you, I will
try that.

When calling Marshal.Structu reToPtr, I will increment the buffer value
just as you did when calling PtrToStructure.

Something like

for(int a=0; a<radioSubscrib erAttributes3Li stSize; a++ )
{
IntPtr temp;
temp = IntPtr(buffer+a *size);
Marshal.Structu reToPtr(radioSu bscriberAttribu tes3List, temp, true);
}

HTH

Rich Claxton wrote:

Hi we have a 3rd party in process com dll, which was written In C++ and our
client is in c#.

All is working fine apart from we get a callback from the DLL which contains
an array of structures.

The callback signature looks like this,

With the list stored in the radioSubscriber Attributes3List , which is defined
in the type library which was created when we imported the com dll into .net

unsafe private void GroupManager_Ge tRadioSubscribe rsConfirmation( uint
radioSubscriber Attributes3List Size, ref tcsRadioSubscri berAttributes3_ t
radioSubscriber Attributes3List , tcsBoolean_t endOfCollection , short cookie);

trouble is we only get the first structure back, if I use the code below.

tcsRadioSubscri berAttributes3_ t[] DATA = new
tcsRadioSubscri berAttributes3_ t[3];
temp = Marshal.AllocCo TaskMem(IntPtr. Size);
buffer = Marshal.AllocCo TaskMem(IntPtr. Size);

//get the address in buffer
Marshal.Structu reToPtr(radioSu bscriberAttribu tes3List, buffer, true);
temp = buffer;

for(int a=0; a<radioSubscrib erAttributes3Li stSize; a++ )
{
DATA[a] =
(tcsRadioSubscr iberAttributes3 _t)Marshal.PtrT oStructure(temp ,radioSubscribe rAttributes3Lis t.GetType());
temp = (IntPtr)((int)b uffer +
Marshal.SizeOf( radioSubscriber Attributes3List .GetType()));
}

I guess StructureToPtr copies the first item from the list passed to us,
into managed memory, and not the rest.

Any help, as if we don’t get this working we will have to write the client
in Delphi !!!!

Cheers Rich.

[Rich Claxton]

Thanks for that, but still no luck.

I think the main problem is that we are getting the adress of the first
struture when we do StructureToPoin ter, but when i look in memmory at this
address i can't see any other struture data that should be on the array after
the first one.

I think the COM c++ is passing us the address of the 1st item in the array
of stuctures and not the array, so when we call StuctureToPoint er we only get
1 stucture.

"Jianwei Sun" wrote:

Rich,

I cannot gurantee this is the right answer, but if I were you, I will
try that.

When calling Marshal.Structu reToPtr, I will increment the buffer value
just as you did when calling PtrToStructure.

Something like

for(int a=0; a<radioSubscrib erAttributes3Li stSize; a++ )
{
IntPtr temp;
temp = IntPtr(buffer+a *size);
Marshal.Structu reToPtr(radioSu bscriberAttribu tes3List, temp, true);
}

HTH

Rich Claxton wrote:

Hi we have a 3rd party in process com dll, which was written In C++ and our
client is in c#.

All is working fine apart from we get a callback from the DLL which contains
an array of structures.

The callback signature looks like this,

With the list stored in the radioSubscriber Attributes3List , which is defined
in the type library which was created when we imported the com dll into .net

unsafe private void GroupManager_Ge tRadioSubscribe rsConfirmation( uint
radioSubscriber Attributes3List Size, ref tcsRadioSubscri berAttributes3_ t
radioSubscriber Attributes3List , tcsBoolean_t endOfCollection , short cookie);

trouble is we only get the first structure back, if I use the code below.

tcsRadioSubscri berAttributes3_ t[] DATA = new
tcsRadioSubscri berAttributes3_ t[3];
temp = Marshal.AllocCo TaskMem(IntPtr. Size);
buffer = Marshal.AllocCo TaskMem(IntPtr. Size);

//get the address in buffer
Marshal.Structu reToPtr(radioSu bscriberAttribu tes3List, buffer, true);
temp = buffer;

for(int a=0; a<radioSubscrib erAttributes3Li stSize; a++ )
{
DATA[a] =
(tcsRadioSubscr iberAttributes3 _t)Marshal.PtrT oStructure(temp ,radioSubscribe rAttributes3Lis t.GetType());
temp = (IntPtr)((int)b uffer +
Marshal.SizeOf( radioSubscriber Attributes3List .GetType()));
}

I guess StructureToPtr copies the first item from the list passed to us,
into managed memory, and not the rest.

Any help, as if we don’t get this working we will have to write the client
in Delphi !!!!

Cheers Rich.

[Mattias Sjögren]

Rich,

With the list stored in the radioSubscriber Attributes3List , which is defined
in the type library which was created when we imported the com dll into .net

unsafe private void GroupManager_Ge tRadioSubscribe rsConfirmation( uint
radioSubscribe rAttributes3Lis tSize, ref tcsRadioSubscri berAttributes3_ t
radioSubscribe rAttributes3Lis t, tcsBoolean_t endOfCollection , short cookie);

trouble is we only get the first structure back, if I use the code below.

And that's all you're going to get as long as the parameter is
declared as "ref tcsRadioSubscri berAttributes3_ t". You'll have to
change that to a real array or an IntPtr by modifying the interop
assembly. How to do that is explained in

http://msdn.microsoft.com/library/en...opassembly.asp
Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.

[Rich Claxton]

"Mattias Sjögren" wrote:

Rich,

With the list stored in the radioSubscriber Attributes3List , which is defined
in the type library which was created when we imported the com dll into .net

unsafe private void GroupManager_Ge tRadioSubscribe rsConfirmation( uint
radioSubscribe rAttributes3Lis tSize, ref tcsRadioSubscri berAttributes3_ t
radioSubscribe rAttributes3Lis t, tcsBoolean_t endOfCollection , short cookie);

trouble is we only get the first structure back, if I use the code below.

And that's all you're going to get as long as the parameter is
declared as "ref tcsRadioSubscri berAttributes3_ t". You'll have to
change that to a real array or an IntPtr by modifying the interop
assembly. How to do that is explained in

http://msdn.microsoft.com/library/en...opassembly.asp
Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.

Thought as much, thanks for the link.

Cheers Rich.

[Rich Claxton]

"Mattias Sjögren" wrote:

Rich,

With the list stored in the radioSubscriber Attributes3List , which is defined
in the type library which was created when we imported the com dll into .net

unsafe private void GroupManager_Ge tRadioSubscribe rsConfirmation( uint
radioSubscribe rAttributes3Lis tSize, ref tcsRadioSubscri berAttributes3_ t
radioSubscribe rAttributes3Lis t, tcsBoolean_t endOfCollection , short cookie);

trouble is we only get the first structure back, if I use the code below.

And that's all you're going to get as long as the parameter is
declared as "ref tcsRadioSubscri berAttributes3_ t". You'll have to
change that to a real array or an IntPtr by modifying the interop
assembly. How to do that is explained in

http://msdn.microsoft.com/library/en...opassembly.asp
Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.

[Rich Claxton]

Made the changes and it works fine.

another question is this pointing to managed or unmanaged code, i guess
managed as i didnt have to decare the code as unsafe.

Cheers Rich.

"Mattias Sjögren" wrote:

Rich,

With the list stored in the radioSubscriber Attributes3List , which is defined
in the type library which was created when we imported the com dll into .net

unsafe private void GroupManager_Ge tRadioSubscribe rsConfirmation( uint
radioSubscribe rAttributes3Lis tSize, ref tcsRadioSubscri berAttributes3_ t
radioSubscribe rAttributes3Lis t, tcsBoolean_t endOfCollection , short cookie);

trouble is we only get the first structure back, if I use the code below.

And that's all you're going to get as long as the parameter is
declared as "ref tcsRadioSubscri berAttributes3_ t". You'll have to
change that to a real array or an IntPtr by modifying the interop
assembly. How to do that is explained in

http://msdn.microsoft.com/library/en...opassembly.asp
Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.

[Mattias Sjögren]

Rich,

another question is this pointing to managed or unmanaged code, i guess
managed as i didnt have to decare the code as unsafe.

You mean the IntPtr? It's a pointer to the _memory_ (not code) where
the caller allocated the structs. Since the caller is a native C++
library it's most likely not the managed heap, but rather a native
heap or stack.
Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.