Dynamic link library - database applications, Visual Basic Programming

DYNAMIC LINK LIBRARY 

The dynamic link library (dll) permits one copy of a function to be shared among some parallel executing programs. The dll is a file that contains a number of modules. The function in a dll is connected to a program which uses it when the application is run. Every time the program executes the dll is connected to the program.

The dynamic-link library (DLL) is a module which contains functions and data that can be used by the other module.

The DLL can define 2 kinds of functions: Internal and Exported.

Exported : The exported functions are intended to be called by the other modules, as well as from within the DLL where they are defined.

Internal : The Functions are normally intended to be called only from within the DLL where they are defined. Though a DLL can export data, its data is normally used only by its functions. Though, there is nothing to prevent the other module from reading or writing that address.

The DLLs provide a way to modularize applications so that the functionality can be updated and reused more easily. They also help to reduce memory overhead when some applications use the same functionality at the same time, as though each application gets its own copy of the data, from which they can share the code.

The API (Windows application programming interface) is implemented as a set of the dynamiclink libraries, therefore any process which uses the Windows API uses the dynamic linking.

  •  About Dynamic-Link Libraries
  •  Using Dynamic-Link Libraries
  •  Dynamic-Link Library Reference

Even though the DLLs and applications are both executable program modules, they vary in some ways. To the end-user, the most obvious difference is that the DLLs are not programs which can be directly executed. There are 2 primary differences from the system's point of view between the applications and DLLs:

An application can have multiple illustration of itself running in the system concurrently, while a DLL can have only one instance.

An application can own things like a global memory stack, file handles, and a message queue, whereas DLL cannot.

Posted Date: 10/10/2012 2:42:28 AM | Location : United States







Related Discussions:- Dynamic link library - database applications, Assignment Help, Ask Question on Dynamic link library - database applications, Get Answer, Expert's Help, Dynamic link library - database applications Discussions

Write discussion on Dynamic link library - database applications
Your posts are moderated
Related Questions
how to make dictionary in vb using ms access

Properties: Every control has a default property related with it. The default property does not require to be named when you are functioning. The control Check box as value

1. Create a new solution file named Ch03HandsOnProject1. 2. Rename the form and set the filename of the form to frmMain and frmMain.vb, respectively. 3. Set the appropriate p

Variable Length Strings: The Strings can be declared using As or $ as shown in the code below; the msg and msg1 are the two strings and they are assigned the values using '='.

Message Routing: The system posts the messages to a first-in, first-out queue known as the message queue or it sends the messages directly to a window procedure. The Messages

how to add the hangman images

SDK PROGRAMMING The SDK programming is a developing Win 32 based programs using the Win 32 API that directly interact with the hardware. Therefore the execution of the SDK prog

Shopping Cart Purpose – Allows user to browse while keeping track of the items in which they will purchase at the end on the order page link and this will give a final price for al

FILE SYSTEM CONTROLS There are 3 file system controls as shown in figure. The drive list box, directory list box & the file list box. The drive list box control is used to exhi

flow chart symbols