Marshalling a SAFEARRAY from an ATL component into CS.

[Tronster Hartley]

I've written an ATL 7.1 component and have a C# 1.1 client that is
consuming it. The ATL component has a method with a [out,retval] that
returns a SAFEARRAY of INTs, but my C# component chokes on it.
The C# code:

// Display a message box with a value from the ATL control
private void GoButton_Click( object sender, System.EventArg s e)
{
SAServerLib.bob Class foo = new SAServerLib.bob Class();

object o = foo.Populate();
MessageBox.Show ( o.ToString() );

int[] ch = (int[])o;
MessageBox.Show ( ch.ToString() );
}
I receive an exception on:
int[] ch = (int[])o;

With the message being:
"An unhandled exception of type 'System.Invalid CastException' occurred
in Safearrays.exe

Additional information: Specified cast is not valid."
ATL code:

// Populate a safe array with the value "321".
STDMETHODIMP Cbob::Populate( SAFEARRAY** saData)
{
SAFEARRAYBOUND rgsabound[1];
rgsabound[0].lLbound = 0;
rgsabound[0].cElements = 3;

*saData = SafeArrayCreate (VT_BSTR, 1, rgsabound);

long c = 3;
long lCount = 0L;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );

c = 2;
lCount++;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );

c = 1;
lCount++;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );

return S_OK;
}
All of this code is from a sample application I'm just trying to prove
the concept with. (Eventually I'll be returning SAFEARRAY's of custom
structures.)

I've googled and MSDNed for some information, but Any advice would be
greatly appreciated.

Cheers.

[Ollie Riches]

have you check out this page on MSDN:

http://msdn.microsoft.com/library/de...gForArrays.asp

HTH

Ollie Riches

"Tronster Hartley" <tr************ **@thomson.com> wrote in message
news:uf******** *****@TK2MSFTNG P12.phx.gbl...

I've written an ATL 7.1 component and have a C# 1.1 client that is
consuming it. The ATL component has a method with a [out,retval] that
returns a SAFEARRAY of INTs, but my C# component chokes on it.
The C# code:

// Display a message box with a value from the ATL control
private void GoButton_Click( object sender, System.EventArg s e)
{
SAServerLib.bob Class foo = new SAServerLib.bob Class();

object o = foo.Populate();
MessageBox.Show ( o.ToString() );
int[] ch = (int[])o;
MessageBox.Show ( ch.ToString() );
}
I receive an exception on:
int[] ch = (int[])o;

With the message being:
"An unhandled exception of type 'System.Invalid CastException' occurred in
Safearrays.exe

Additional information: Specified cast is not valid."
ATL code:

// Populate a safe array with the value "321".
STDMETHODIMP Cbob::Populate( SAFEARRAY** saData)
{
SAFEARRAYBOUND rgsabound[1];
rgsabound[0].lLbound = 0;
rgsabound[0].cElements = 3;

*saData = SafeArrayCreate (VT_BSTR, 1, rgsabound);

long c = 3;
long lCount = 0L;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
c = 2;
lCount++;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
c = 1;
lCount++;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
return S_OK;
}
All of this code is from a sample application I'm just trying to prove the
concept with. (Eventually I'll be returning SAFEARRAY's of custom
structures.)

I've googled and MSDNed for some information, but Any advice would be
greatly appreciated.

Cheers.

[Willy Denoyette [MVP]]

Please post your method declaration (midl).
I'm not clear how you declared your SAFEARRAY return argument, as far as I
know you can't return a safearray (retval)
Willy.

"Tronster Hartley" <tr************ **@thomson.com> wrote in message
news:uf******** *****@TK2MSFTNG P12.phx.gbl...

I've written an ATL 7.1 component and have a C# 1.1 client that is
consuming it. The ATL component has a method with a [out,retval] that
returns a SAFEARRAY of INTs, but my C# component chokes on it.
The C# code:

// Display a message box with a value from the ATL control
private void GoButton_Click( object sender, System.EventArg s e)
{
SAServerLib.bob Class foo = new SAServerLib.bob Class();

object o = foo.Populate();
MessageBox.Show ( o.ToString() );
int[] ch = (int[])o;
MessageBox.Show ( ch.ToString() );
}
I receive an exception on:
int[] ch = (int[])o;

With the message being:
"An unhandled exception of type 'System.Invalid CastException' occurred in
Safearrays.exe

Additional information: Specified cast is not valid."
ATL code:

// Populate a safe array with the value "321".
STDMETHODIMP Cbob::Populate( SAFEARRAY** saData)
{
SAFEARRAYBOUND rgsabound[1];
rgsabound[0].lLbound = 0;
rgsabound[0].cElements = 3;

*saData = SafeArrayCreate (VT_BSTR, 1, rgsabound);

long c = 3;
long lCount = 0L;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
c = 2;
lCount++;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
c = 1;
lCount++;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
return S_OK;
}
All of this code is from a sample application I'm just trying to prove the
concept with. (Eventually I'll be returning SAFEARRAY's of custom
structures.)

I've googled and MSDNed for some information, but Any advice would be
greatly appreciated.

Cheers.

[Tronster Hartley]

You may be right in terms of SAFEARRAYs not able to be returned; the
MSDN article pointed to by Ollie Riches seems to show that an in or
in/out parameter is the only type that can be decorated for marshaling.
:( (I hope that isn't true.)


Below is the IDL:

import "oaidl.idl" ;
import "ocidl.idl" ;

[
uuid(0A15D60D-B87D-4B1C-AA85-07BF51CB6FF0),
version(1.0),
helpstring("SAS erver 1.0 Type Library")
]
library SAServerLib
{
importlib("stdo le2.tlb");
[
uuid(908FF2FF-CA80-4858-BD8D-89CFF5CAFEA3),
helpstring("_Ib obEvents Interface")
]
dispinterface _IbobEvents
{
properties:
methods:
};

[
object,
uuid(1C4CD34D-8B6D-4571-B00A-4930FD1FFAF0),
dual,
nonextensible,
helpstring("Ibo b Interface"),
pointer_default (unique)
]
interface Ibob : IDispatch{
[id(1), helpstring("met hod Populate")]
HRESULT Populate([out,retval] SAFEARRAY** saData);
};

[
uuid(D9C4E6D0-4A9F-4A8F-95EC-6ACACBACB67C),
helpstring("bob Class")
]
coclass bob
{
[default] interface Ibob;
[default, source] dispinterface _IbobEvents;
};
};

Willy Denoyette [MVP] wrote:

Please post your method declaration (midl).
I'm not clear how you declared your SAFEARRAY return argument, as far as I
know you can't return a safearray (retval)
Willy.

"Tronster Hartley" <tr************ **@thomson.com> wrote in message
news:uf******** *****@TK2MSFTNG P12.phx.gbl...

I've written an ATL 7.1 component and have a C# 1.1 client that is
consuming it. The ATL component has a method with a [out,retval] that
returns a SAFEARRAY of INTs, but my C# component chokes on it.
The C# code:

// Display a message box with a value from the ATL control
private void GoButton_Click( object sender, System.EventArg s e)
{
SAServerLib.bob Class foo = new SAServerLib.bob Class();

object o = foo.Populate();
MessageBox.Show ( o.ToString() );
int[] ch = (int[])o;
MessageBox.Show ( ch.ToString() );
}
I receive an exception on:
int[] ch = (int[])o;

With the message being:
"An unhandled exception of type 'System.Invalid CastException' occurred in
Safearrays.exe

Additional information: Specified cast is not valid."
ATL code:

// Populate a safe array with the value "321".
STDMETHODIMP Cbob::Populate( SAFEARRAY** saData)
{
SAFEARRAYBOUND rgsabound[1];
rgsabound[0].lLbound = 0;
rgsabound[0].cElements = 3;

*saData = SafeArrayCreate (VT_BSTR, 1, rgsabound);

long c = 3;
long lCount = 0L;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
c = 2;
lCount++;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
c = 1;
lCount++;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
return S_OK;
}
All of this code is from a sample application I'm just trying to prove the
concept with. (Eventually I'll be returning SAFEARRAY's of custom
structures.)

I've googled and MSDNed for some information, but Any advice would be
greatly appreciated.

Cheers.

[Tronster Hartley]

Thank you Ollie.

I had not found that page in my searches. I'm gleaning information from
it now as I try to get this to work.

Cheers.
Ollie Riches wrote:

have you check out this page on MSDN:

http://msdn.microsoft.com/library/de...gForArrays.asp

HTH

Ollie Riches

"Tronster Hartley" <tr************ **@thomson.com> wrote in message
news:uf******** *****@TK2MSFTNG P12.phx.gbl...

I've written an ATL 7.1 component and have a C# 1.1 client that is
consuming it. The ATL component has a method with a [out,retval] that
returns a SAFEARRAY of INTs, but my C# component chokes on it.
The C# code:

// Display a message box with a value from the ATL control
private void GoButton_Click( object sender, System.EventArg s e)
{
SAServerLib.bob Class foo = new SAServerLib.bob Class();

object o = foo.Populate();
MessageBox.Show ( o.ToString() );
int[] ch = (int[])o;
MessageBox.Show ( ch.ToString() );
}
I receive an exception on:
int[] ch = (int[])o;

With the message being:
"An unhandled exception of type 'System.Invalid CastException' occurred in
Safearrays.exe

Additional information: Specified cast is not valid."
ATL code:

// Populate a safe array with the value "321".
STDMETHODIMP Cbob::Populate( SAFEARRAY** saData)
{
SAFEARRAYBOUND rgsabound[1];
rgsabound[0].lLbound = 0;
rgsabound[0].cElements = 3;

*saData = SafeArrayCreate (VT_BSTR, 1, rgsabound);

long c = 3;
long lCount = 0L;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
c = 2;
lCount++;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
c = 1;
lCount++;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
return S_OK;
}
All of this code is from a sample application I'm just trying to prove the
concept with. (Eventually I'll be returning SAFEARRAY's of custom
structures.)

I've googled and MSDNed for some information, but Any advice would be
greatly appreciated.

Cheers.

[Willy Denoyette [MVP]]

You should indicate the type of SAFEARRAY element, so your IDL should look
like this:

[id(1), helpstring("met hod Populate")] HRESULT Populate([out,
retval]SAFEARRAY(int)* psa);

STDMETHODIMP CBob::Populate( SAFEARRAY** psa)
{

As such in C#, you can return into an int[]

int[] ia = obj.Populate();

Willy.

Tronster Hartley" <tr************ **@thomson.com> wrote in message
news:%2******** ********@TK2MSF TNGP14.phx.gbl. ..

You may be right in terms of SAFEARRAYs not able to be returned; the MSDN
article pointed to by Ollie Riches seems to show that an in or in/out
parameter is the only type that can be decorated for marshaling. :( (I
hope that isn't true.)

Below is the IDL:

import "oaidl.idl" ;
import "ocidl.idl" ;

[
uuid(0A15D60D-B87D-4B1C-AA85-07BF51CB6FF0),
version(1.0),
helpstring("SAS erver 1.0 Type Library")
]
library SAServerLib
{
importlib("stdo le2.tlb");
[
uuid(908FF2FF-CA80-4858-BD8D-89CFF5CAFEA3),
helpstring("_Ib obEvents Interface")
]
dispinterface _IbobEvents
{
properties:
methods:
};

[
object,
uuid(1C4CD34D-8B6D-4571-B00A-4930FD1FFAF0),
dual,
nonextensible,
helpstring("Ibo b Interface"),
pointer_default (unique)
]
interface Ibob : IDispatch{
[id(1), helpstring("met hod Populate")]
HRESULT Populate([out,retval] SAFEARRAY** saData);
};

[
uuid(D9C4E6D0-4A9F-4A8F-95EC-6ACACBACB67C),
helpstring("bob Class")
]
coclass bob
{
[default] interface Ibob;
[default, source] dispinterface _IbobEvents;
};
};

Willy Denoyette [MVP] wrote:

Please post your method declaration (midl).
I'm not clear how you declared your SAFEARRAY return argument, as far as
I know you can't return a safearray (retval)
Willy.

"Tronster Hartley" <tr************ **@thomson.com> wrote in message
news:uf******** *****@TK2MSFTNG P12.phx.gbl...

I've written an ATL 7.1 component and have a C# 1.1 client that is
consuming it. The ATL component has a method with a [out,retval] that
returns a SAFEARRAY of INTs, but my C# component chokes on it.
The C# code:

// Display a message box with a value from the ATL control
private void GoButton_Click( object sender, System.EventArg s e)
{
SAServerLib.bob Class foo = new SAServerLib.bob Class();

object o = foo.Populate();
MessageBox.Show ( o.ToString() );
int[] ch = (int[])o;
MessageBox.Show ( ch.ToString() );
}
I receive an exception on:
int[] ch = (int[])o;

With the message being:
"An unhandled exception of type 'System.Invalid CastException' occurred
in Safearrays.exe

Additional information: Specified cast is not valid."
ATL code:

// Populate a safe array with the value "321".
STDMETHODIMP Cbob::Populate( SAFEARRAY** saData)
{
SAFEARRAYBOUND rgsabound[1];
rgsabound[0].lLbound = 0;
rgsabound[0].cElements = 3;

*saData = SafeArrayCreate (VT_BSTR, 1, rgsabound);

long c = 3;
long lCount = 0L;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
c = 2;
lCount++;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
c = 1;
lCount++;
SafeArrayPutEle ment(*saData, &lCount, static_cast<voi d*>(&c) );
return S_OK;
}
All of this code is from a sample application I'm just trying to prove
the concept with. (Eventually I'll be returning SAFEARRAY's of custom
structures.)

I've googled and MSDNed for some information, but Any advice would be
greatly appreciated.

Cheers.