Find memory leaks in Delphi

In my previous jobs I always used Java, when I began to program in Delphi the biggest obstacle was freeing the memory!
I didn’t realized how useful was the Java Garbage Collector until I began to use Delphi! 😯

The best practice to avoid memory leaks in Delphi is to free the memory using a template like this:

myList := TStringList.Create; // Create the Object
try

  ... myList usage ...

finally
  FreeAndNil(myList); // Free the memory
end;
</pre>

…but obviously this is not always possible 😦

How to find memory leaks

To overcame these problems I found very usefull to set:

ReportMemoryLeaksOnShutdown := True;

It shows a list of memory leaks (if any) when you close the program.

If you want to perform this check only in your debug build, you can use:

{$IFDEF DEBUG}
  ReportMemoryLeaksOnShutdown := True;
{$ENDIF}

If you want to use this check only if you are in Delphi Debug Mode (F9), you can use:

ReportMemoryLeaksOnShutdown := DebugHook <> 0;

Examples:

Following an example of alert caused by TStringList.Create;

…and an example of alert caused by TButton.Create(nil);

Related Links:

Memory Leak Notification in Delphi
Top 4 Memory Leak Fix Tools