Why would I want to use a DLL

[Guru2B]

Hi!

I was wondering if there's an easy answer to this one.

Why would I want to use a dll file in my apps and how would I create one? I have been getting on quite nicely without making my own, but somehow I feel as though I am missing out on something.

Thanks,
Guru2B

 

[Guest_imported]

Dll files are cool. Basically with a dll file you can just make an API call to the dll. This includes all windows dll files. Basically a dll file is a bunch of prewritten code that is used by software. Ever want to play a sound file...

#If Win32 Then
Declare Function sndPlaySound Lib "winmm" Alias "sndPlaySoundA" _
(ByVal lpSound As String, ByVal flag As Long) As Long
#ElseIf Win16 Then
Declare Function sndPlaySound Lib "MMSYSTEM" _
(ByVal lpszSoundName As String, ByVal uFlags As Integer) As Integer
#End If

dim iReturn as integer
Private sub Form_Load()
iReturn = sndPlaySound("C:\winnt\sound.wav", 0)
end sub


The above form would play a sound file using the winmm.dll or the mmsystem.dll if in win16.. It uses the built in function sndPlaySoundA. There are zillions of uses for dlls (The most juicy stuff of programming).. If you wanted to create your own dll.. Lets say you have 2 programs that share alot of the same funcions + procedures.. Instead having the functions and procedures defined in each programs source, you can put these functions + procedures into a dll file. If your company makes alot of software, or does alot of updates, or you want to make the exe smaller, or it to use less memory, there are alot of reasons to make a dll file.

 

[Guru2B]

Well thank you for the info. Is there anything special that has to be done with the installer? I use the packaging and deployment wizard. Does that handle the registration of the dlls automatically?

Guru2B