I am currently writing a managed C++ wrapper to interface with some unmanaged C++ code so I can utilise the code in C#. Everything is working absolutely fine except I need to be able to pass in a managed buffer from C# in a C++ function, modify the buffer in the function and pass the results back to C#. I currently have the following:
C++ code:
public : void Play(System::Byte buffer[])
{
char buffer2[44100];
// Fill the unmanaged buffer
pSidplay2->play(buffer2, 44100);
//buffer = buffer2*;
// Copy the unmanaged data into the managed buffer
for (int i = 0; i < 44100; i++)
{
buffer
= buffer2;}
}
C# code:
private void button1_Click(object sender, EventArgs e)
{
sc = new SidClass();
byte[] ba = new Byte[44100];
// Initialise the sound object
sc.Initialise();
// Create binary file for the raw wave data
bi = new BinaryWriter(File.Open(@"C:\seesharp3", FileMode.Create));
// Play ten seconds of sound
for (int a = 0; a < 10; a++)
{
sc.Play(ba);
int b = 1;
bi.Write(ba, 0, 44100);
}
bi.Close();
}
If I step into the C++ code, the information is correctly written into the buffer, the problem I am having is getting that data back into C#. When I compile the following I receive the following errors:
Error 1 The best overloaded method match for 'SidManagedWrapper.SidClass.Play(byte*)' has some invalid arguments C:\Documents and Settings\Damien\My Documents\Visual Studio 2005\SidPlayTester2\Form1.cs 39 17 SidPlayTester2
Error 2 Argument '1': cannot convert from 'byte[]' to 'byte*' C:\Documents and Settings\Damien\My Documents\Visual Studio 2005\SidPlayTester2\Form1.cs 39 25 SidPlayTester2
I know these are because I am not using the correct data types. Can someone show me what changes I need to make
Many thanks,
Damien.
Moving a byte array between C# and C++
C&#35;noob
void Play(array<Byte>^ buffer);
For example:
#include "stdafx.h"
using namespace System;
public ref class Test {
public:
void Play(array<Byte>^ buffer) {
unsigned char buffer2[100];
for (int i = 0; i < 100; ++i) {
buffer2[ i ] = buffer[ i ];
}
}
};
int main(array<System::String ^> ^args)
{
Test^ t = gcnew Test;
array<Byte>^ buf = gcnew array<Byte>(100);
t->Play(buf);
return 0;
}
AlbinCN
Please tell me if your C++ application is COM If so I can give you a very good idea which is to use "SAFEARRAY unsigned char valueToPass" And that is the best ever interface method to pass a BYTE array from Unmanaged to Managed code.
// Code for cpp file of Interface
STDMETHODIMP CHaberles::PassByteData(SAFEARRAY *palmData)
{
BYTE *arrayOfPalmData;
long lLength; // number of bytes
// lock access to array data
SafeArrayAccessData( palmData, (void*)&arrayOfPalmData );
// get number of elements in array. This is the number of bytes
lLength = palmData->rgsabound->cElements;
arrayOfPalmData =new BYTE[lLength];
memcpy(arrayOfPalmData,palmData->pvData,lLength);
// release the safearray buffer
SafeArrayUnaccessData( palmData );
delete [] arrayOfPalmData; // Pay attention that I have used BYTE Array a local variable here you can do it also by creating the
// BYTE array outside this functions scope and also delete it there also
return S_OK;
}
// Code for header file of Interface
STDMETHOD(PassByteData)(/*[in]*/ SAFEARRAY * palmData);
// Code for idl file of Interface
[id(1), helpstring("method PassByteData")] HRESULT PassByteData([in] SAFEARRAY (unsigned char) palmData);