地产商如何做工程型项目管理系统?揭秘地产商项目管理系统的神奇之处

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;

namespace RealEstate.ProjectManagement.Domain
{
    /// <summary>
    /// 工程项目实体
    /// </summary>
    public class Project
    {
        [Key]
        public Guid Id { get; set; }

        [Required, MaxLength(100)]
        public string Name { get; set; }

        /// <summary>
        /// 项目总建筑面积（平方米）
        /// </summary>
        public decimal TotalArea { get; set; }

        /// <summary>
        /// 项目状态：筹备、在建、交付
        /// </summary>
        public string Status { get; set; }

        public DateTime StartDate { get; set; }

        public DateTime? EndDate { get; set; }

        /// <summary>
        /// 项目下的任务集合
        /// </summary>
        public ICollection<ProjectTask> Tasks { get; set; } = new List<ProjectTask>();
    }

    /// <summary>
    /// 工程任务实体
    /// </summary>
    public class ProjectTask
    {
        [Key]
        public Guid Id { get; set; }

        [Required, MaxLength(200)]
        public string Title { get; set; }

        public Guid ProjectId { get; set; }

        public Project Project { get; set; }

        /// <summary>
        /// 计划开始时间
        /// </summary>
        public DateTime PlannedStart { get; set; }

        /// <summary>
        /// 计划完成时间
        /// </summary>
        public DateTime PlannedEnd { get; set; }

        /// <summary>
        /// 实际完成进度（0-100）
        /// </summary>
        public int Progress { get; set; }
    }
}