face recognition for attendants student

i use visual studio 2017 - C# WHAT ARE THE CODES FOR FACIAL RECOGNITION ? what i need the code to build a program attendants students in school or college etc... The project is a program that prepares students through a video camera directly. attendants by the camera video live that capture and take it to database and matches with the same picture in database, if the picture did not match the teacher can access to attendants and edit it. The main screen type: Management - Teacher - Student each one has a different: ( User name - password ) 1- Management: Teacher and Student information is fully integrated with image three times. 1.1 - this is for TEACHER sign up ( full name - trainer number - email - mobile - address - input image three times - subjects - divisions number - students names ). 1.2 - this is for STUDENT sign up ( full name - trainee number - email - mobile - address - input image three times - subjects - divisions number - teacher name ). 2- Teacher: when sign in offered to him ( teacher name - trainer number -subjects - divisions number - time and date for check in and check out for Attendants - students name and trainee number ). 2.1 - the teacher has access to modify attendants student . ( subject - trainee number - present - absent - % excommunication ) 3- Students: when sign in Offered to him (student's name - trainee number - name of the subject - department number - teacher's name - number of attendance - number of absences - times and date of attendance and departure - percentage of deprivation of materials) * Alert student for his attendant*