public JsonResult IsCourseExist(int Id)
{
List <CourseAssign> teachers = courseBll.GetAssignCourses();
bool isExist = teachers.FirstOrDefault(u => u.CourseId.Equals(Id)) != null;
return(Json(isExist, JsonRequestBehavior.AllowGet));
}
//protected override ValidationResult IsValid(object value, ValidationContext validationContext)
//{
// List<CourseAssign> teachers = courseBll.GetAssignCourses();
// bool isExist = teachers.FirstOrDefault(u => u.CourseId.Equals(value)) != null;
// var assignCourse = (CourseAssign) validationContext.ObjectInstance;
// if (isExist)
// {
// return new ValidationResult("Course Already assign");
// }
// else
// {
// return ValidationResult.Success;
// }
//}
public override bool IsValid(object value)
{
List <CourseAssign> teachers = courseBll.GetAssignCourses();
bool isExist = teachers.FirstOrDefault(u => u.CourseId.Equals(value)) != null;
return(!isExist);
}