using c# - verify that 2 addresses were in a transaction

[BaiMangal]

doing an app just to learn... and I need to know whats the best or what options I have to do this:

what would you use to verify that 2 addresses were in a transactin using C#?
I need to know if address A (received or send btc) from/to address B and I am doing my app in C#

can I use bitcoin client to achieve this?

thanks!

[BaiMangal]

is blockchain.info API my best choice?

[biteasy]

You could also try our REST API:
https://www.biteasy.com/developers

[myrez]

I would use bitcoin daemon, but for that you need server for daemon.
And you could use c# as well.

[mcaizgk2]

You can use this library: https://github.com/GeorgeKimionis/BitcoinLib for C#, GetTransactionSenderAddress  returns the transaction's inputs' previous owing address(es), which is what you're asking for.

However it's worth mentioning that your client's sending addresses are actually different that your receiving addresses, so the challenge here is to find whether the sender for any given transaction's receiving address is the one you thought it was going to be in the first place.