Using LoadResData with Binary Data

• Professional and Enterprise Editions of Microsoft Visual Basic, 16-bit and 32-bit, for Windows, version 4.0

SUMMARY

Visual Basic 4.0 introduces a new function called LoadResData, which can be used to retrieve binary data from a resource (.res) file. The sample in this document demonstrates how to create a resource file and use binary data from it in all versions of Visual Basic 4.0.

MORE INFORMATION

The following code is a resource script that can be compile by using the 16 and 32-bit versions of Rc.exe.

///////////////////////////////////////////////////////////////////////
//////
   // Myres.rc - 16 & 32 bit script. This must be compiled into two .res
   // files using the 16 & 32 bit versions of RC.

///////////////////////////////////////////////////////////////////////
//////
   // Wave Resources - You must copy these files from your \Windows
   // directory to the directory where your .rc script resides.

   CHIMES                  WAVE    DISCARDABLE     "Chimes.wav"
   DING                    WAVE    DISCARDABLE     "Ding.wav"

Steps to Create a Resource File

1. Save the above code in Notepad as Myres.rc in the directory where Rc.exe exists on your hard disk.

2. Copy Chimes.wav and Ding.wav from your Windows directory (or your \Windows\Media directory on Windows 95) to the same directory where you saved Myres.rc.

3. At the command line, type "RC -r Myres.rc" If you want a 16-bit and 32- bit version of your resource file, then you will have to save two copies of your resource file as Myres32.rc and Myres16.rc, and compile each separately with the appropriate resource compiler.

Steps to Run the Sample Application

1. Create a new project and add a command button to Form1.

2. Add the following code to Form1:

   '*********************************************************************
   
         ' Form1.frm - Calls PlayWaveRes to play a wave resource file.
   
   '*********************************************************************
   
         Sub Command1_Click()
            PlayWaveRes "Chimes"
            PlayWaveRes "Ding"
         End Sub
   
   

3. Add your resource file to the project.

4. Type the following code in a new code module:

   '*********************************************************************
   
         ' Baswave.bas - Plays a wave file from a resource using LoadResData.
   
   '*********************************************************************
   
         Option Explicit
         #If Win32 Then
           Private Declare Function sndPlaySound Lib "winmm" Alias
   

                            (lpszSoundName As Any, ByVal uFlags As

      #Else
        Private Declare Function sndPlaySound Lib "MMSYSTEM" ( _
                           lpszSoundName As Any, ByVal uFlags%) As Integer
      #End If

'*********************************************************************

      '  Flag values for wFlags parameter.

'*********************************************************************

      Public Const SND_SYNC = &H0        ' Play synchronously (default)
      'Public Const SND_ASYNC = &H1       ' Play asynchronously (see
                                          ' note below!)
      Public Const SND_NODEFAULT = &H2   ' Don't use default sound
      Public Const SND_MEMORY = &H4      ' lpszSoundName points to a
                                         ' memory file.
      Public Const SND_LOOP = &H8        ' Loop the sound until next
                                         ' sndPlaySound.
      Public Const SND_NOSTOP = &H10     ' Don't stop any currently
                                         ' playing sound.

'*********************************************************************

      ' Plays a wave file from a resource.

'*********************************************************************

      Public Sub PlayWaveRes(vntResourceID As Variant, Optional vntFlags)
      '-----------------------------------------------------------------
      ' WARNING:  If you want to play sound files asynchronously in
      '           Win32, then you MUST change bytSound() from a local
      '           variable to a module-level or static variable. Doing
      '           this prevents your array from being destroyed before
      '           sndPlaySound is complete. If you fail to do this, you
      '           will pass an invalid memory pointer, which will cause
      '           a GPF in the Multimedia Control Interface (MCI).
      '-----------------------------------------------------------------
      Dim bytSound() As Byte ' Always store binary data in byte arrays!

      bytSound = LoadResData(vntResourceID, "WAVE")

      If IsMissing(vntFlags) Then
         vntFlags = SND_NODEFAULT Or SND_SYNC Or SND_MEMORY
      End If

      If (vntFlags And SND_MEMORY) = 0 Then
         vntFlags = vntFlags Or SND_MEMORY
      End If

      sndPlaySound bytSound(0), vntFlags
      End Sub