Detect before file is executing via C or C#

I am C# developer and I need to be notified by somehow when any executable file tries to run by Windows user.
I must be notified via it's hash(sha256) value or byte array, so that I can judge if the file is in white list or in black list.
I can judge whether it's in white list or not via checking it's hash value.
I have these hash values in text file in the same computer that user is using.
So, when it's in white list, my C# application won't do anyting but when it's in black list, my C# appliacation must be able to stop the executable file to run.
Stopping the file to run must be done before it actually runs.