VB3 Emulating QuickBasic's SOUND Statement in Visual BasicLast reviewed: January 8, 1997Article ID: Q71102 |
The information in this article applies to:
SUMMARYThe SOUND statement found in Microsoft QuickBasic is not implemented within Microsoft Visual Basic. You can perform sound through a Windows API call that is equivalent to the QuickBasic SOUND statement.
MORE INFORMATIONThe QuickBasic version of the SOUND statement can be executed by calling several Windows 3.0 API function calls. Within Windows, you must open up a VoiceQueue with the OpenSound call routine. Using the function SetVoiceSound, place all of the values corresponding to the desired frequencies and durations. Once the VoiceQueue has the desired frequencies and durations, you start the process by calling StartSound. After the sounds have been played, you must free up the VoiceQueue by calling CloseSound. If you plan on placing a large amount of information into the VoiceQueue, you may need to resize the VoiceQueue buffer by calling the SetVoiceQueueSize function. After executing the StartSound function, you cannot place any more sound into the VoiceQueue until the VoiceQueue is depleted. Placing more sound into the queue will overwrite any information that was previously in the VoiceQueue. If you are going to place sound into the VoiceQueue after a StartSound statement, you will need to call WaitSoundState with an argument of one. When WaitSoundState returns NULL, the VoiceQueue is empty and processing can continue. Below is an example of using the Windows API function calls, which will imitate the QuickBasic SOUND statement: In the general section place the following:
Declare Function OpenSound Lib "sound.drv" () As Integer Declare Function VoiceQueueSize Lib "sound.drv" (ByVal nVoice%, ByVal nBytes%) As Integer Declare Function SetVoiceSound Lib "sound.drv" (ByVal nSource%, ByVal Freq&, ByVal nDuration%) As Integer Declare Function StartSound Lib "sound.drv" () As Integer Declare Function CloseSound Lib "sound.drv" () As Integer Declare Function WaitSoundState Lib "sound.drv" (ByVal State%) As IntegerNOTE: All Declare statements above each must be placed on one line. The SetVoiceSound takes two arguments. The first variable, Freq, is a two WORD parameter. The HIGH WORD will hold the actual frequency in hertz. The LOW WORD will hold the fractional frequency. The formula, X * 2 ^ 16, will shift the variable "X" into the HIGH WORD location. The second variable, Duration%, is the duration in clock ticks. There are 18.2 tick clicks per second on all Intel computers. The following simplistic example shows how you can place several frequencies and durations into the VoiceQueue before starting the sound by calling the StartSound function:
Sub Form_Click () Suc% = OpenSound() S% = SetVoiceSound(1, 100 * 2 ^ 16, 100) ' Frequency = 100 hz S% = SetVoiceSound(1, 90 * 2 ^ 16, 90) ' Frequency = 90 hz S% = SetVoiceSound(1, 80 * 2 ^ 16, 90) ' Frequency = 80 hz S% = StartSound() While (WaitSoundState(1) <> 0): Wend ' Wait for sound to play. Succ% = CloseSound() End SubThe following is another simple example, which creates a siren sound:
REFERENCES"Programming Windows: the Microsoft Guide to Writing Applications for Windows 3," Charles Petzold, Microsoft Press, 1990 "Microsoft Windows Software Development Kit: Reference Volume 1," version 3.0 WINSDK.HLP file shipped with Microsoft Windows 3.0 Software Development Kit
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