Library tutorials & articles

API Programming Series #1

By Sreejath S. Warrier, published on 13 Jul 2002
Sreejath S. Warrier
Page 4 of 7
  1. Foreword
  2. So what's API
  3. Where does the API reside?
  4. How can we access API functions from VB?
  5. Why use the API when I can achieve most of the thi
  6. What are the cons?
  7. Conclusion

How can we access API functions from VB?

Since these functions are encapsulated within external DLLs they are not available in VB by default. Before invoking (i.e. using) them, we must declare them. Usually this is done in the General | Declarations part of the module in which they are to be used.

One important thing should be remembered while declaring API functions within a form module. VB does not allow public Declare statements within form modules. So the Declare statements should be explicitly specified as Private since all object module members are considered Public by default. But this makes them invisible outside the module in which they are defined. So the functions should be declared in every module that needs to use them.
Declaring them in a separate .BAS module where they can be declared as Public and are therefore accessible to all the modules eliminates this duplication. This also permits easier maintenance.

Note: We will see how to declare and use API functions in the second article of this series.

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Comments

  1. amiteshwar singh
    31 May 2007 at 18:41

    plz help me 4r api.gv some books on apiSad [:(]

  2. Praseeda
    09 Mar 2007 at 00:50

    The article is really valuble.It will give good exposure to Windows API

  3. hackaback
    19 Sep 2005 at 13:01

    hey ther, can anyone gve me an idea how to retrive the system's information in vb so that i could create a system dedicated application. or any other method

  4. Barry Whyte
    12 Mar 2003 at 19:38

    Look in the registry:


    For WinNT/2K (I assume this works on XP too...) 


    HKLM\Software\Microsoft\Windows NT\Current Version\RegisteredOrganization



    You'll need to find a way to read this key as VB can't do it on it's own.  You can use API Routines Reg*.  Check msdn (http://msdn.microsoft.com/library) for more details.

  5. RT
    28 Nov 2002 at 09:36

    Hey
    just wondering if anyone has an advice for a problem tha i'm trying to solve:


    I need to make an API call from VBA within Excel to get information about the compnany that the machine is registered to.  I was wondering if anyones knows the DLL file it's in or any other way of getting this informmation into Excel


    Really appreciate anyone's input.


    Thanks RT

  6. fanen
    13 Jul 2002 at 09:04

    this looks quite promising, at least if he keeps goin' and wud be nice if he exposes some calls... for guys who want to expand their "Database"

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