This is very useful because you may first check if the conditions are met to call the DLL before actually loading the DLL, for example check if the DLL is located where it should.
If you statically load a DLL (the default), then your application won’t start if the DLL is not present. You could as well dynamically load the DLL (LoadLibrary) to avoid this issue, but it is a little bit more work for you to declare function pointer and the get each function address (GetProcAddress) by code. Using delayed directive is much easier. Just add delayed keyword in each function declaration and suddenly a static DLL is loaded the first time one of his functions is called. If you never call a DLL’s function, then the DLL is not loaded at all.
A declaration looks like this:
function GetSomething: Integer; external 'somelibrary.dll' delayed;
This directive exists since Delphi 2010. There is valuable documentation on Embarcadero DocWiki at this URL: http://docwiki.embarcadero.com/RADStudio/XE4/en/Libraries_and_Packages#Delayed_Loading And you can find some code sample here: http://docwiki.embarcadero.com/CodeExamples/XE4/en/DelayedLoading_(Delphi)
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