Mega Code Archive
Dynamic loading and binding of dlls
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Sometimes you may need to load a DLL at runtime, for example
if you have a couple of different DLLs to choose between
to have a concept for optional functionality.
This small source code shows how to load the DLL with LoadLibrary and use the returned handle to access (bind) the functions that are contained:
{ function declaration }
type
TfncCnx = function (s : string) : THandle;
var
cnx : TfncCnx;
begin
{ load the DLL and get the function's address }
h := LoadLibrary('myDll');
if h = 0 then
begin
ShowMessage ('DLL not available');
end
else
begin
@cnx := GetProcAddress(h, 'myProc');
if @cnx = nil then
begin
{ function not found.. misspelled? }
ShowMessage ('blub');
end
else
begin
{ call the function as usually }
x := cnx('alpha');
end;
{ unload the DLL }
FreeLibrary(h);
end;
end;
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