Callback function pointer on CF 2.0 from unmanaged C DLL -> NotSupportedExceptionGetFunctionPointerF

[Marcel Ruff]

Hi,

i'm not sure if this is a bug in the CF2, so here are the details:

I have
One Windows Mobile CE 5.1.195 (IPAQ hw6910)
One Windows CE 4.2 PDA with Arm XScale (Psion Teklogix)

On both i have installed compact framework .net 2.0 SP1
(cgacutil.exe shows 1.0.4292.2 and 2.0.6129)

I have compiled the C# exe and C dll code with VC++ 2005.
When i want to call a native unmanaged C dll with a callback
function pointer i get:

----------
NotSupportedException:
System.Runtime.InteropServices.Marshal.GetFunctionPointerForDelegateInternal
----------

During startup my System.Environment.Version.ToString()
reports CF 2.0.6129

Here is the code:
// C#
public delegate bool FPtr(int value);
public class LibWrap
{
[DllImport("test.dll")]
public static extern void TestCallBack(IntPtr cb, int value);
}
public static bool DoSomething( int value )
{
Console.WriteLine( "\n[C#]: Callback called: {0}", value );
return true;
}


And i call it like this:

// C#
FPtr cb = new FPtr(DoSomething);
IntPtr cbForDelegate = Marshal.GetFunctionPointerForDelegate(cb);
LibWrap.TestCallBack(cbForDelegate, 99); // throws exception!


The C test.dll header:
extern "C" {
typedef bool (CALLBACK *FPTR)( int i );
__declspec (dllexport) extern void TestCallBack( FPTR pf, int value );
}

The C test.dll source:
extern "C" void TestCallBack( FPTR pf, int value )
{
bool res;
printf( "\ndll: Received value: %i", value );
printf( "\ndll: Passing to callback..." );
res = (*pf)(value);

if( res )
printf( "dll: Callback returned true.\n" );
else
printf( "dll: Callback returned false.\n" );
}


I have tried to compile the dll with /TC or /TP (c++),
same result.

Can anybody shed some light on this?

Thanks
Marcel

 

[Paul G. Tobey [eMVP]]

Why does this sound so familiar? Let's finish the thread in the other group
before you start another one, OK?

Paul T.

 

[Marcel Ruff]

Why does this sound so familiar? Let's finish the thread in the other group
before you start another one, OK?

Sorry, i just thought this group is more appropriate,
so i transfered the thread to here with more details.
(usually i avoid cross posting)

Marcel

Paul T.

Hi,

i'm not sure if this is a bug in the CF2, so here are the details:

I have
One Windows Mobile CE 5.1.195 (IPAQ hw6910)
One Windows CE 4.2 PDA with Arm XScale (Psion Teklogix)

On both i have installed compact framework .net 2.0 SP1
(cgacutil.exe shows 1.0.4292.2 and 2.0.6129)

I have compiled the C# exe and C dll code with VC++ 2005.
When i want to call a native unmanaged C dll with a callback
function pointer i get:

----------
NotSupportedException:

System.Runtime.InteropServices.Marshal.GetFunctionPointerForDelegateInternal
----------

During startup my System.Environment.Version.ToString()
reports CF 2.0.6129

Here is the code:
// C#
public delegate bool FPtr(int value);
public class LibWrap
{
[DllImport("test.dll")]
public static extern void TestCallBack(IntPtr cb, int value);
}
public static bool DoSomething( int value )
{
Console.WriteLine( "\n[C#]: Callback called: {0}", value );
return true;
}


And i call it like this:

// C#
FPtr cb = new FPtr(DoSomething);
IntPtr cbForDelegate = Marshal.GetFunctionPointerForDelegate(cb);
LibWrap.TestCallBack(cbForDelegate, 99); // throws exception!


The C test.dll header:
extern "C" {
typedef bool (CALLBACK *FPTR)( int i );
__declspec (dllexport) extern void TestCallBack( FPTR pf, int value );
}

The C test.dll source:
extern "C" void TestCallBack( FPTR pf, int value )
{
bool res;
printf( "\ndll: Received value: %i", value );
printf( "\ndll: Passing to callback..." );
res = (*pf)(value);

if( res )
printf( "dll: Callback returned true.\n" );
else
printf( "dll: Callback returned false.\n" );
}


I have tried to compile the dll with /TC or /TP (c++),
same result.

Can anybody shed some light on this?

Thanks
Marcel