EntityFramework批量更新对象的某些属性

假设更新学生实体

public class Student{
	public int Id { get; set; }
	public string Name { get; set; }
	public int Age { get; set; }
	public bool Gender { get; set; }	//True=>male, False=>female
}

数据库上下文

public class StudentDbContext : DbContext{
	public DbSet<Student> Students { get; set; }
}

对应通用的Repository

private readonly StudentDbContext _db;
public int UpdateByProperties(List<Student> students, params Expression<Func<Student, dynamic>>[] properties)
{
	students.ForEach(student => 
	{
		foreach (var propety in properties)
		{
			_db.Entry(student).Property(property).IsModified = true;
		}
	});

	return _db.SaveChanges();
}

表达式Expression中传入Student对象，返回Student属性，应当使用Func。又因为属性类型是可变的，所以这里返回类型使用dynamic，综上Func<Student, dynamic>。
使用示例

var stu = _db.Students.FirstOrDefault(s => s.ID == 1);
stu.Name = "New";
stu.Age++;
UpdateByProperties(stu, s => s.Name, s => s.Age);