DLL's and COM components...

[ChandruNM]

Hi...<br>Now I started learning COM basics and really finding interesting things from Dale Rogerson.<br>&nbsp;<br>I have a basic quest, what is the difference between DLL and a COM component. As per my knowledge, DLL can also be act as a Component which would load dynamically and share the same by others also.. This is true with COM also...<br>So can anybody clarify this doubt..<br><br><br>Regards <br>Chandru NM

 

[calahans]

A DLL is a dynamic link library - this is a component which can be accessed by your application when it needs to extend it function. A DLL has a clearly defined API (application programmers interface) which is a contract between DLL developer and the application programmer user. The beauty of the DLL route is that you DLL is reuseable in other projects.<br><br>COM is an design architecture. COM stands for component object model - this model included DLLs and active-x exes. COM is about modularising an application for reuse, DLLs are an example of this.<br><br>HTH <p>Cal<br><a href=mailto: > </a><br><a href= > </a><br>

 

[juliaroberts]

hi!<br><br>A dll is just a vehicle for the COM component. In other words it just acts as a carrier to the COM component. <br><br>You can also use an exe as the carrier of the component.<br><br>for ex. IN VB you can create a COM component that can be an ActiveX exe or an ActiveX DLL.<br><br>regards

 

[gleason]

Also, there are certain types of things that you can't do in an ActiveX DLL that you can in an ActiveX EXE.&nbsp;&nbsp;For example, we created a COM object that displays a non-modal dialog window.&nbsp;&nbsp;We instantiate the object from inside a Visual C++ application.&nbsp;&nbsp;When the object was first written (using VB) we intended to release it as an ActiveX DLL but were forced to create an ActiveX EXE because an ActiveX DLL cannot display non-modal dialog windows.<br> <p>Pat Gleason<br><a href=mailto:gleason@megsinet.net>gleason@megsinet.net</a><br><a href= > </a><br>