在VB5中如何使机箱内的小喇叭发出不同的声音？

2019-11-18 17:36:41

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->-chengdx
回答1:
Mmsound.drv是小喇叭的系统接口，很多API的书都有用法介绍
-219张晶
回答2:
使用VB中的beep语句，但这只能发出一种声音。如果想发出不同声音，可以
使用API函数。详情如下：（摘自VB-Helper）
UsetheBeepAPIfunction.

Thisexampledemonstratestwointerestingthings.First,itshowshowtomakeabeepofanyfrequencyanddurationratherthanusingthestandardtoneyougetwiththeBeepstatement.

Second,notethattheBeepAPIfunctionhasthesamenameasVisualBasic'sBeepstatement.Todifferentiatethem,youcanassignanewnametotheBeepAPIfunctioninitsDeclarestatement.Itisknownas"Beep"inthelibrary(theAliasstatement)butitisknownasAPIBeeptothePRogram.

Youcanusethistechniquetodifferentiatebetweenfunctionswiththesamename,oryoucanuseittogiveAPIfunctionsanamethatiseasiertowrite(forexample,iftheAPInameisverylong).

Inthedeclarationssection:

OptionExplicit
PrivateDeclareFunctionAPIBeepLib"kernel32"Alias"Beep"(ByValdwFreqAsLong,ByValdwDurationAsLong)AsLong
'Tomakeabeeplasting500millisecondswithfrequencyspecifiedinthe
'TextBoxtxtFrequency(try1000forstarters):

PrivateSubCommand1_Click()
DimfrequencyAsLong

frequency=CLng(txtFrequency.Text)
APIBeepfrequency,500
EndSub
-Prisoner->

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