I'm trying to convert a C structure that include function pointer into a VB.Net structure that contain delegates. (Only .Net 2.0 and 3.0 users should attempt this.) When I call a function in an unmanaged dll that fills the structure, I get the following error (nontrapable exception):
Can anybody tell me how I got my delegate definitions or signatures messed up?Code:InvalidFunctionPointerInDelegate was detected
Message: Invalid function pointer 0xb6390c91 was passed into the runtime to be converted to a delegate. Passing in invalid function pointers to be converted to delegates can cause crashes, corruption or data loss.
Original structure:
Translated to vb.netCode:typedef struct
{
int version; // module type (IN_VER)
char *description; // description of module, with version string
HWND hMainWindow; // winamp's main window (filled in by winamp)
HINSTANCE hDllInstance; // DLL instance handle (Also filled in by winamp)
char *FileExtensions; // "mp3\0Layer 3 MPEG\0mp2\0Layer 2 MPEG\0mpg\0Layer 1 MPEG\0"
// May be altered from Config, so the user can select what they want
int is_seekable; // is this stream seekable?
int UsesOutputPlug; // does this plug-in use the output plug-ins? (musn't ever change, ever :)
void (*Config)(HWND hwndParent); // configuration dialog
void (*About)(HWND hwndParent); // about dialog
void (*Init)(); // called at program init
void (*Quit)(); // called at program quit
void (*GetFileInfo)(char *file, char *title, int *length_in_ms); // if file == NULL, current playing is used
int (*InfoBox)(char *file, HWND hwndParent);
int (*IsOurFile)(char *fn); // called before extension checks, to allow detection of mms://, etc
// playback stuff
int (*Play)(char *fn); // return zero on success, -1 on file-not-found, some other value on other (stopping winamp) error
void (*Pause)(); // pause stream
void (*UnPause)(); // unpause stream
int (*IsPaused)(); // ispaused? return 1 if paused, 0 if not
void (*Stop)(); // stop (unload) stream
// time stuff
int (*GetLength)(); // get length in ms
int (*GetOutputTime)(); // returns current output time in ms. (usually returns outMod->GetOutputTime()
void (*SetOutputTime)(int time_in_ms); // seeks to point in stream (in ms). Usually you signal yoru thread to seek, which seeks and calls outMod->Flush()..
// volume stuff
void (*SetVolume)(int volume); // from 0 to 255.. usually just call outMod->SetVolume
void (*SetPan)(int pan); // from -127 to 127.. usually just call outMod->SetPan
// in-window builtin vis stuff
void (*SAVSAInit)(int maxlatency_in_ms, int srate); // call once in Play(). maxlatency_in_ms should be the value returned from outMod->Open()
// call after opening audio device with max latency in ms and samplerate
void (*SAVSADeInit)(); // call in Stop()
// simple vis supplying mode
void (*SAAddPCMData)(void *PCMData, int nch, int bps, int timestamp);
// sets the spec data directly from PCM data
// quick and easy way to get vis working :)
// needs at least 576 samples :)
// advanced vis supplying mode, only use if you're cool. Use SAAddPCMData for most stuff.
int (*SAGetMode)(); // gets csa (the current type (4=ws,2=osc,1=spec))
// use when calling SAAdd()
void (*SAAdd)(void *data, int timestamp, int csa); // sets the spec data, filled in by winamp
// vis stuff (plug-in)
// simple vis supplying mode
void (*VSAAddPCMData)(void *PCMData, int nch, int bps, int timestamp); // sets the vis data directly from PCM data
// quick and easy way to get vis working :)
// needs at least 576 samples :)
// advanced vis supplying mode, only use if you're cool. Use VSAAddPCMData for most stuff.
int (*VSAGetMode)(int *specNch, int *waveNch); // use to figure out what to give to VSAAdd
void (*VSAAdd)(void *data, int timestamp); // filled in by winamp, called by plug-in
// call this in Play() to tell the vis plug-ins the current output params.
void (*VSASetInfo)(int nch, int srate);
// dsp plug-in processing:
// (filled in by winamp, called by input plug)
// returns 1 if active (which means that the number of samples returned by dsp_dosamples
// could be greater than went in.. Use it to estimate if you'll have enough room in the
// output buffer
int (*dsp_isactive)();
// returns number of samples to output. This can be as much as twice numsamples.
// be sure to allocate enough buffer for samples, then.
int (*dsp_dosamples)(short int *samples, int numsamples, int bps, int nch, int srate);
// eq stuff
void (*EQSet)(int on, char data[10], int preamp); // 0-64 each, 31 is +0, 0 is +12, 63 is -12. Do nothing to ignore.
// info setting (filled in by winamp)
void (*SetInfo)(int bitrate, int srate, int stereo, int synched); // if -1, changes ignored? :)
Out_Module *outMod; // filled in by winamp, optionally used :)
} In_Module;
VB Code:
Let me know if more information is required.
