De-compile DLL file to source code

ldvhai used Ask the Experts™
Hi Experts.

I have a problem like this: i have a DLL file without source code from the previous programmer who build our business system.

How can I de-compile this DLL file to source code, I have use dotPeek and get the defined variables, but the function is unable to de-compile with the message:

// ISSUE: unable to decompile the method.

Is there anyway to solve this problem?

Thanks for reading this.
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
ste5anSenior Developer

"Decompiling" gives you maybe a working source, you still need to rewrite it (building the solution structure, unit tests, correct naming, documentation). So it will be a lot of work.. I would ask the previous developer, where the source is located. Otherwise, do a clean (green field) rewrite.
Principal Software Engineer
The success of decompilation depends quite a bit on how much debugging and trace support was left in the DLL, and what level of code optimization was applied.

If the original author was competent, as much debug and trace support as possible would have been removed in favor of quicker executing code, and a high level of code optimization would have been applied.  That is the nature of a DLL; it should be well debugged first, then compiled to execute as fast as possible.  The resulting code could prove very difficult to decompile intelligibly.


Thank you for all the help!


Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial