I am going to apply for a US visitor visa from germany with my german passport, I am also a citizen of Iran and i have the Iranian passport would i be able to get the visa or i will be subjected to the travel ban as i have the Iranian nationality?
The latest form of the travel ban is a proclamation that provides in part (at section 3(b)(iv)) that
(b) The suspension of entry pursuant to section 2 of this proclamation shall not apply to:
(iv) any dual national of a country designated under section 2 of this proclamation when the individual is traveling on a passport issued by a non-designated country;
So, because you are traveling with your German passport, the travel ban does not apply to you.
You need a visa. Dual nationals of VWP (Visa Waiver Program) countries and Iraq, Iran, Syria, and Sudan are also no longer eligible to travel or be admitted to the United States under the VWP.
These individuals will still be able to apply for a visa using the regular process at U.S. Embassies or Consulates.