How to Play MIDI Files Using API Calls from Visual Basic

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

SUMMARY

This article demonstrates how to play a MIDI (.MID) file from Visual Basic using the WIN16 or WIN 32 API call named mciSendString. If you have the Professional or Enterprise Editions of Visual Basic version 4.0, you can use the MCI control to play a MIDI file. You don't need to use the APIs.

MORE INFORMATION

Step-by-Step to an Application that Plays a .MID File

1. Start Visual Basic, or if Visual Basic is already running, click New Project on the File menu (ALT, F, N). Form1 is created by default.

2. Add a Command Button (Command1) to Form1.

3. Add the following code to the Command1_Click event of Form1:

      Private Sub Command1_Click()
      Dim ret As Integer
   
      ' The following will open the sequencer with the C:\WIN31\CANYON.MID
      ' file. Canyon is the device_id.
   
      ret = mciSendString( _
      "open c:\windows\CANYON.MID type sequencer alias canyon", 0&, 0, 0)
   
      ' The wait tells the MCI command to complete before returning control
      ' to the application.
   
      ret = mciSendString("play canyon wait", 0&, 0, 0)
   
      ' Close CANYON.MID file and sequencer device
   
      ret = mciSendString("close canyon", 0&, 0, 0)
   
      End Sub
   
   

4. Add the following code to the general declarations section of Form1:

   #If Win32 Then

      Private Declare Function mciSendString Lib "winmm.dll" Alias _
      "mciSendStringA" (ByVal lpstrCommand As String, ByVal  _
      lpstrReturnString As Any, ByVal uReturnLength As Long, ByVal _
      hwndCallback As Long) As Long
   
      #ElseIf Win16 Then
   
      Private Declare Function mciSendString Lib "mmsystem" (ByVal _
      lpstrCommand As String, ByVal lpstrReturnStr As Any, ByVal _
      wReturnLen As Integer, ByVal hCallBack As Integer) As Long
   
      #End If
   
   

5. On the Run menu, click Start (ALT, R, S) or press F5 to run the program.

REFERENCES

More information about mciSendString() can be found in:

• The Multimedia Programmer's Reference on page 3-26.
• Command strings described on pages 7-23 to 7-93 and in the

       WIN31MWH.HLP file shipped with the Windows 3.1 Software Development
       Kit (SDK).