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DELPHI !

      Hi , I am very much happy to invite you to this site . 

I am a delphi devoloper with an experience of two years and I find this language is quite intresting and very useful.But the resource is quite less and I would like to add the resources, that I have collected in my experience.Also I would highly appreciate,if you could provide me with some useful information.

Please send your collection or resources to delphi.techie@gmail.com

 

DELPHI - CONCEPTS

Delphi is one of the wonderfeul programming languages it has amny features embedded into it.

Delphi utilizes the OOPS Concept upto the maximum and hence the programming in Delphi is very Intresting.

 --Inheritance

--Polymorphism

--Override

--OverLoad

--Encapsulation

 

Access Specifiers

--Private

--Protected

--Public

--Published

        Access Specifiers, as the name implies, it refers to the Accessing Property of  fields (variables) or methods(procedures or Function) .

Thank You Very Much !

I thank the site www.delphibasics.co.uk for their resource .My intention is to collect the resources and store it in one place and not for commercial purpose.This site has collection of notes from vaious sites. 

Memory and Object Orientation

Object Orientation has transformed the process of application development. It has allowed complex code to be written in nicely encapsulated modules (objects). When you create an object, Delphi handles the memory allocation for the object as you call the Create method of the object class.

           But there is a down side to this automation that is often overlooked, especially by newcomers, giving rise to memory leaks.

 What are memory leaks?

Put simply, every time you no longer use an object in your code, you should delete it, thereby freeing the memory it was allocated. If you don't do this, your program can allocate more and more memory as it runs. This failure to discard unwanted blocks of memory is called a memory leak. Run the program long enough and you will use up the memory resources of your PC and the PC will slow down and eventually hang.

(NOTE:This is a very real problem in many programs, including commercial applications)

 
 

Some more subtle object allocations

On Windows XP, the Task Manager shows the memory allocated to running processes. It is useful to observe the allocation amount for your application as you use it. There is likely to be some upping of memory useage as you use different functions, but repeated calls to the same function should normally yield a stable memory allocation.

        There are times when it is not obvious when memory is allocated, or when memory should be discarded. Just as Delphi cannot keep track of object references, you may not easily follow references in your code. This is particularly true when you call routines that create objects for you.

Delphi itself has Run Time Library functions that allocate memory. In particular, the FindFirst, FindNext and FindClose set of functions is worthy of a mention.

When FindFirst runs, it attempts to find the first file in a folder that satisfies your search criteria. If it finds a file, then it creates an object that keeps track of where it found this file. This is needed for subsequent calls to FindNext.

However, it means that you are obliged to call FindClose in order to discard the memory used by this object. So here is an example of object allocation without an explicit call to a Create constructor.

      You have been warned!