BSP_GetFileName and VB 6
 

I'm trying to use the BSP_GetFileName routine in visual basic, however it always returns a buffer containing nothing but zeros. Here is the code I'm using:

Public Declare Function FindWindow Lib "user32" Alias _
"FindWindowA" (ByVal lpClassName As String, _
ByVal lpWindowName As Long) As Long

Public Declare Function CopyDataSendMessage Lib "user32" Alias _
"SendMessageA" (ByVal WndID As Long, ByVal wMsg As Long, _
ByVal wParam As Long, ByRef lParam As COPYDATASTRUCT) As Long

Public Declare Function lstrcpy Lib "kernel32" Alias "lstrcpyA" _
(ByVal lpString1 As String, ByVal lpString2 As String) _
As Long

Public Type COPYDATASTRUCT
dwData As Long
cbData As Long
lpData As Long
End Type

Public Const WM_COPYDATA = &H4A
Public Const BSP_GetFileName = &H1010B
Public bspClass As String
Public hWndBSPlayer As Long
Public RetVal As Long

Public Function BSGetCurrentFile() As String
Dim nullpos As Integer
bspClass = "BSPlayer"
hWndBSPlayer = FindWindow(bspClass, 0)
If hWndBSPlayer = 0 Then 'can't find BSPlayer
BSGetCurrentFile = ""
Exit Function
End If
Dim buffer As String * 256

Dim cds As COPYDATASTRUCT
cds.dwData = BSP_GetFileName
cds.lpData = lstrcpy(buffer, buffer)
' Copies filename to itself. Nothing happens, but returns the address for the pointer to the string!
cds.cbData = 4

RetVal = CopyDataSendMessage(hWndBSPlayer, WM_COPYDATA, Form1.hwnd, cds)
nullpos = InStr(buffer, Chr(0))
If nullpos > 1 Then BSGetCurrentFile = Left(buffer, nullpos - 1)
End Function

the code executes correctly and CopyDataSendMessage returns a value of 1 but the currently open filename isn't returned. I'm using BSPlayer Pro
Version 1.22 Build 817, 24. Feb 2005. I am using a very similar routine to open a file, and that works fine. Any help would be appreciated.

Ok ignore the previous. I should have been using varptr to get a pointer to buffer and for some reason it doesn't work with a fixed length string.

However it now returns a value which contains only question marks followed by an I. eg. ????????????i. Having searched through previous posts I found that someone else is having the same problem. Does anyone have a fix?

Can you post your routine to open a file?
Thanks :wink:

P.S. I'm trying to find a solution to this problem, but I have no time now... If I can resolve this I'll make you know!

Routine to open file as requested:

Public Sub BSPAddFile(filename As String)
' Adds a file to the playlist

hWndBSPlayer = FindWindow(bspClass, 0)
If hWndBSPlayer = 0 Then 'can't find BSPlayer
Exit Sub
End If

Dim cds As COPYDATASTRUCT
cds.dwData = BSP_OpenFile
cds.lpData = lstrcpy(filename, filename)
' Copies filename to itself. Nothing happens,
' but returns the address for the pointer to the string!
cds.cbData = Len(filename) + 1

RetVal = CopyDataSendMessage(hWndBSPlayer, WM_COPYDATA, 0&, cds)

End Sub

Is this post perhaps of any use to you?
:wink:

Unfortunally it didn't help me... :(
But thanks for the link :)

If the file extension terminates with "g" (for example file_name.mpg) the name returned is something like ????????????g, and if the file name is looong the name returned is composed only by "?".

@immortal
Thank you for providing the OpenFile code, my fault was that I used VarPtr instead of lstrcpy... :P
Thank you.

I hope someone will solve the retrive filename issue :wink:

I encountered other problems with the SendMessage call.
For BSP_GetSkin the behaviour is the same as for BSP_GetFileName.

Every time I send a seeking position to BSplayer with the BSP_Seek message, BSplayer seek bar moves to time 00:20:40.
The same behaviour for the BSP_SetVol message, but this time BSplayer goes to 100% Volume level.

No problems with BSP_GETVERSION, BSP_OpenFile (thanks to immortal), BSP_GetMovLen, BSP_GetMovPos, BSP_GetVol, BSP_SetSkin, BSP_LoadSub, BSP_LoadAudio, BSP_LoadPlaylist, BSP_LoadPlaylistInt and with all BSP_(action) actions.
The only Action I can't use is BSP_VolUp. When I send this action (BSP_VolUp=1) BSplayer does nothing.

With BSP_GetStatus I have a strange behaviour:
I get the STOP, PLAY and PAUSE status, but Instead of "No movie open" (value=4) I get value=-1 ....

I don't know anything about VB, but I just want to report that I don't have problems using BSP_GetFileName with C++.
This does not solve your problem, but at least you know it's not a bug in BSplayer.

Rafke P.

In fact I think it's a VB problem, or (maybe ONLY) our fault. It seems like the handle of the program is passed in a bad way (this is my conclusion after reading the post linked by BSPeter, and since the BSP_GetSkin and BSP_GetFileName commands are the only ones that require the program to send BSplayer its handle)... but I don't know why :cry: (I'm not a skilled programmer)

If anybody can tell me something about BSP_Seek and BSP_SetVol commands (if you Rafke want to try them, and maybe also BSP_GetStatus, in c++) I will know if it's a BSplayer or VB problem.

Thank you :)
bye :wink:

Tizio,

I will try the other commands in the following days.

This is the way I send the message in C++ :
Notice that I'm typecasting (I believe that's what it's called...I'm a lousy programmer I just keep typing code until it works) the application handle and cds. Maybe you need to do that too.

I will report back on the other commands.
Rafke

EDIT: I just tried the GetStatus command and I can confirm the behaviour you're seeing : when no file is open the command returns -1

EDIT2: The SetVol command is working, but the volume slider on the skin doesn't follow.The volume, however, is set correctly.

Thank you Rafke for your tests!!

Yes, it's typecasting (AFAIK), but I don't know how to cast a WPARAM in VB, have to search the web :wink: . For cds (I think) I don't need to typecast since it works ok with OpenFile and SetSkin...

For SetVol I have to try a different way, but I don't think it's the correct one :?.. we will see...

I'm "glad" to know that at least the GetStatus command doesn't work also with C++ (it's not my fault :) )

Thak you again :D

Ok, BSP_SetVol and BSP_Seek now work perfectly (my error was that I sent the address of the value and not the value itself to BSplayer :P ).
And I can confirm that the volume slider on the skin doesn't follow the volume level (and no OSD about volume changes are shown).

I tried typecasting my appHWND, but it didn't work :( ...
WPARAM is (in Win32 systems) a 32bit value passed as a parameter to a window procedure or callback function, and my appHWND (Form1.hWnd) is a Long value (4byte=32bit), but with value between -2.147.483.648 and 2.147.483.647, so I typecasted it to Single (4byte=32bit), which has values between -3,402823E38 and -1,401298E-45 for negative values and between 1,401298E-45 and 3,402823E38 for positive values (but since the handle has no decimals it's of no use typecating this way...).
BTW, the value sent to BSplayer is a 32bit value, the same as WPARAM typecasted values... and the handle value is correct (I checked it with other programs that retrieve the program handle)...

I have no more ideas :?

Now the only problematic commands are: BSP_GetSkin, BSP_GetFileName and BSP_VolUp.

Bye :wink:

Today I tested GetSkin and VolUp.
Both work as they should. With the VolUp even the volume slider on the skin works.

I still have one idea left for you and the topicstarter:
maybe you are passing the wrong handle (all the rest looks OK to me).
Output the handle somewhere (in a textbox or something) and then check with another application.

@Tizio, since you know Girder you can use that to check the handle :
add a new command
go to targetting options and drag the crosshair to your application
check what handle corresponds to the result.

I know Girder is not made for these sort of things, but it was the first that came to mind. I tested it and it works, but feel free to use what you like.

Rafke

One of those programs is Girder, and the handle read by Girder is the same I send to BSplayer. I have checked which handle I send to BSplayer in debug mode and also with a textbox (obviously the value is the same) and it matches the one indicated in Girder...

Thank you anyway for the suggestion :)

VolDown works perfectly for me, and the volume slider moves while I change the volume value, but (I don't know why) VolUp doesn't work.
And I've noticed that also BSP_OpenSub = 62 doesn't work, while BSP_LoadSub works.... :shock:

:roll: I don't know what to do (I will pass to c++ when I will have more time :) )

Oops, I missed that part. Sorry about that :oops:

For the moment I'm out of ideas too.
I will let you know when I think of something.

I don't know if this will make any sense (I had too much wine and know [censored] about VB), but maybe it helps.

Compare your code to the c++ code

If I understand correctly you put the adres of a pointer to buffer in lpData

Now here is the C++ code

Now if I understand this correctly (like I said before I don't know c++ either :D )

adr contains the adress of the pointer to buffer, but
lpData contains the adress of the pointer to the adres of the pointer to the buffer

I tried to fix it in VB6 and didn't succeed, but I hope this is somehow of use to you.

Rafke P.

EDIT:On a more sober note: this doesn't explain why the open file is working though.

Thank you Rafke for the clues, but it seems I can't obtain the address of the variable (only the pointer to it).
And searching on the web I found bad behaviours with VB when you try to send API calls by sending the pointer or the address of a variable (plus VB uses UNICODE strings, instead of ANSI that are used for API calls, but neither canverting the string to ANSI works)...
I have an idea, maybe to read the portion of memory of the pointer sent to BSplayer, but I have no time at the moment..

(There are a lot of problems when the few things you know are self and quick learned :roll: and that is my VB knowledge)

Re:BSP_GetFileName and VB 6
 

This the correct method.
Try it and tell me if it works.

Public Declare Function FindWindow Lib "user32" Alias _
"FindWindowA" (ByVal lpClassName As String, _
ByVal lpWindowName As Long) As Long

Public Declare Function CopyDataSendMessage Lib "user32" Alias _
"SendMessageA" (ByVal WndID As Long, ByVal wMsg As Long, _
ByVal wParam As Long, ByRef lParam As COPYDATASTRUCT) As Long

Public Type COPYDATASTRUCT
dwData As Long
cbData As Long
lpData As Long
End Type

Public Const WM_COPYDATA = &H4A
Public Const BSP_GetFileName = &H1010B
Public bspClass As String
Public hWndBSPlayer As Long
Public RetVal As Long

Public Function BSGetCurrentFile() As String
Dim nullpos As Integer
bspClass = "BSPlayer"
hWndBSPlayer = FindWindow(bspClass, vbNullString)
If hWndBSPlayer = 0 Then 'can't find BSPlayer
BSGetCurrentFile = ""
Exit Function
End If
Dim buffer As String

Dim cds As COPYDATASTRUCT

buffer = Space$(256)
cds.dwData = BSP_GetFileName
cds.lpData = VarPtr(buffer)
cds.cbData = 4

RetVal = CopyDataSendMessage(hWndBSPlayer, WM_COPYDATA, Form1.hwnd, cds)
buffer = StrConv(buffer, vbUnicode)
nullpos = InStr(buffer, vbNullChar)
If nullpos > 1 Then BSGetCurrentFile = Left(buffer, nullpos - 1)
End Function