Callback function from c++ DLL

[barrow_matt]

I have found many examples that I thought may help but I cannot get my head around callback functions from the c++ DLL.

I have the following code

global.cs

	[DllImport("my.dll")]
	unsafe public static extern UInt16 RegisterDetectCallback(void* detectCallbackFunction);

In my own code I have tried a few things but basically want the following functionality

program.cs

public void DetectCallback()
{
    // some functionality...
}

private void button1_Click(object sender, EventArgs e)
        {
                //various code...
                UInt16 result = DLLFunctions.RegisterDetectCallback(DetectCallback());
        }

I have tried a few things without success, can anybody point me in the right direction please? i know the above is incorrect as the DLL requires a pointer and i'm trying to pass a function, but hopefully the intention is clear.

Also is it possible to do this without unsafe code? without changing the c++, or is this a requirement when passing functions as parameters in this way?

Thanks

Matt