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I'm really hoping there's a way to do this in VB 5.
VB 5 has finally given us access to actual addresses, but seemingly only to pass on to win32 API calls that were written in C.
In C, the operation *(address) returns to you the actual value stored at address, and not the address.
If I have an array of data that I know starts at address data_buff_ptr, I really want to be able access that data by referencing that beginning address. This is a piece of cake in C/C++, but how the hell can you do this in VB?
Anyone know if this is possible, without getting too ridiculously complicated (like using a third party control or dll)?
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I can't remember the syntax of C so I'll try to explain in english there arre 3 pointer functions in VB which have been there all along but are undocumented
VarPtr(lngA) returns a long pointer to lngA
StrPtr(strA) returns a long pointer to the first integer in a wide character array. (VB does a hell of a lot of string converting behind the scenes though, It could just be a character array)
VarPtr(StrA) Returns a Pointer to a Pointer to the first integer in a wide Character arrey etc...
ObjPtr(objA) returns a pointer to the Object objA (I don't know much about COM, I suspect it's a pointer to the Data specific to the object rather than it's interface.
To get the Target of the Pointer You have to use the CopyMemory API
[Edited by Sam Finch on 04-22-2000 at 11:35 PM]
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Thanks for the reply Sam.
You know, I've just realized how ridiculously simple it is to do this with a dll in c. In my present project I'm using a dll I wrote to compress and decompress files. All I need to do is export one more function:
int _stdcall return_value(unsigned char* buff_ptr) {
return *(buff_ptr)
}
Of course, this will return the value one byte at a time; a few more lines of code and another parameter to indicate the data size would generalize it.
This is kind of absurd. It greatly upsets my aesthetic sensibilities. It's like a great big ugly festering sore on the butt of Visual Basic, a language and environment that otherwise has a great deal of beauty.
To me, the best of all worlds would be if Visual C++ included an optional VB type IDE that gave you the same kind of event-driven programming while using C/C++ for the actual language that was used. I see no reason whatsoever why this could not be done.
