public class TemplateConfiguration : EntityTypeConfiguration<Template>
    {
        /// <summary>
        /// 构造函数
        /// </summary>
        public TemplateConfiguration()
        {
            HasKey(x => x.Id);
            Property(x => x.Id)
                .IsRequired()
                .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
            Property(x => x.ClassId)
                .IsRequired();
            Property(x => x.Name)
                .IsRequired()
                .HasMaxLength(50);
            Property(x => x.Content)
                .IsRequired()
                .HasMaxLength(null);
            Property(s => s.AddDate)
                .IsRequired();
            HasRequired(a => a.TemplateClass).WithMany(c => c.Templates).HasForeignKey(a => a.ClassId);
        }
    }