最近在写学校的SRTP项目--学生信息管理系统，其中涉及到对以下信息的数据库操作。当然持久化之前要对数据的合法性进行验证，如果非法要提示合理信息，如果有其他问题会抛出异常。
这些信息几乎按种来分类，每类一个数据表，也就是一类实体，除了各个实体属性不同其余操作就相差不大了。那么怎样来对这些信息进行统一的操作呢？这里就用到了多态。下面就用我的实现来作为例子吧，如果大家有什么好的想法可以提出来，不对的地方希望大家指出。谢谢，呵呵！
涉及到信息：
1. 基本信息：学号，姓名，班级，专业，年龄，身份证号，籍贯等
2. 家庭信息：家庭住址，家庭电话，家庭成员信息等
3. 奖学金信息：包括获得奖学金的数额，时间，项目等
4. 活动信息：参加的活动，活动举行的时间，活动的结果等
5. 资助信息：资助的项目，资助金额，资助时间等
6. 处分信息：处分的时间，原因，是否被撤销等
7. 素质测评信息：包括测评的时间，文体，时间等的得分情况
8. 参加的比赛信息：包括比赛名称，时间，结果等
实现概括：
每类信息的添加，修改都有一个专门的VIEW，也就是一个WinForm，他们共同继承Form_base，base处理共同问题，具体问题子类各自处理
From_Base实现：
Code
1
using System;
2using System.Collections.Generic;
3using System.ComponentModel;
4using System.Data;
5using System.Drawing;
6using System.Linq;
7using System.Text;
8using System.Windows.Forms;
9
10using StudentManagerV3.DataBase;
11
12namespace StudentManagerV3
13
{
14
public partial class Form_Base : Form
15
{
16 private StudentManagerDataContext context;
17 private bool isEidt = false;
18 /**//// <summary>
19 /// 视图的引用，当模型发生改变时更新视图，呈献给用户新结果
20
/// </summary>
21 protected DataGridView GridView { get; set; }
22
23 /**//// <summary>
24 /// 如果是编辑信息，实体不为空，强制转换成用户需要的实体
25 /// </summary>
26 protected object Entity { get; set; }
27
28 /**//// <summary>
29 /// 每个Form都单独维护自己的一个Context，防止产生冲突或者引发错误
30 /// </summary>
31 protected StudentManagerDataContext Context
32 {
33 get
34 {
35 if (context == null) throw new ArgumentNullException();
36 return context;
37 }
38 }
39
40 /**//// <summary>
41 /// 标识是编辑信息还是添加新信息，
42 /// </summary>
43 protected bool IsEdit { get { return isEidt; } }
44
45 public Form_Base()
46 { }
47
48 public Form_Base(object entity)
49 {
50 if (entity != null) { isEidt = true; this.Entity = entity; }
51 //AppInfo包含了系统的配置信息
52 context = new StudentManagerDataContext(AppInfo.ConnectionString);
53 }
54
55 //判断当前操作的实体是否有效
56 protected bool ISLegal()
57 {
58 //全局信息，标识当前实体
59 return DataPool.StudentNumber != "0";
60 }
61
62 public void ShowHandleEntityError(string message)
63 {
64 if (message != null)
65 SMSApplication.WriteLogAndShowSuggestiveInfo(message,
66 SysConfig.Document.SelectNodes(XmlSelectorInfo.ApplicationError)[0].InnerText);
67 else SMSApplication.WriteLogAndShowSuggestiveInfo(message,
68 SysConfig.Document.SelectNodes(XmlSelectorInfo.EntityError)[0].InnerText);
69 }
70
71 /**//// <summary>
72 /// 添加，修改学生信息（除基本信息）的逻辑,统一处理（多态的实现）
73 /// </summary>
74 protected void AddOrEditInfo()
75 {
76 try
77 {
78 if (ISLegal())
79 {
80 ConstructEntityInfo();
81 SMSApplication.ShowOperateSucceedResult();
82 }
83 else ShowHandleEntityError(null); ;
84 }
85 catch (FormatException exp)
86 {
87 //SMSApplication系统写入日志和显示友好信息的组件，XmlSelectorInfo记录xml配置文件寻址信息
88 SMSApplication.WriteLogAndShowSuggestiveInfo(exp.Message, SysConfig.Document.SelectNodes(XmlSelectorInfo.FormatError)[0].InnerText);
89 }
90 catch (OverflowException exo)
91 {
92 SMSApplication.WriteLogAndShowSuggestiveInfo(exo.Message, SysConfig.Document.SelectNodes(XmlSelectorInfo.OverFlowError)[0].InnerText);
93 }
94 catch (Exception ex)
95 {
96 ShowHandleEntityError(ex.Message);
97 }
98 this.Dispose();
99 }
100 /**//// <summary>
101 /// 获得新信息实体的方法，由子类实现
102 /// </summary>
103 protected virtual void ConstructEntityInfo()
104 {
105 throw new NotImplementedException();
106 }
107
108 }
109
}
110其中几个子类的实现：
Code
1using System;
2using System.Collections.Generic;
3using System.ComponentModel;
4using System.Data;
5using System.Drawing;
6using System.Linq;
7using System.Text;
8using System.Windows.Forms;
9
10using StudentManagerV3.DataBase;
11
12namespace StudentManagerV3
13{
14 public partial class Form_Game : Form_Base
15 {
16 /**//// <summary>
17 /// 修改添加时对应的实体
18 /// </summary>
19 private Game game = new Game();
20
21 public Form_Game(DataGridView view, object entity)
22 : base(entity)
23 {
24 //这个通过Base放到父类中更合适，这样每个子类又减少了代码量，放到这里也算是错误代码的样例介绍把。呵呵
25 this.GridView = view;
26 this.Entity = entity;
27
28 InitializeComponent();
29
30 //如果是编辑，自然要初始化控件内容
31 if (IsEdit)
32 {
33 game = entity as Game;
34 dateTimePicker_GameTime.Text = game.GameDateTime.ToString();
35 textBox_GameName.Text = game.GameName;
36 textBox_GameResult.Text = game.GameResult;
37 }
38 }
39
40 private void button_AddGame_Click(object sender, EventArgs e)
41 {
42 //调用父类的逻辑
43 AddOrEditInfo();
44 }
45 /**//// <summary>
46 /// 实现父类的方法
47 /// </summary>
48 protected override void ConstructEntityInfo()
49 {
50 if (IsEdit)
51 game = (from ga in Context.Games where ga.GameID == ((Game)Entity).GameID select ga).Single();
52 game.GameResult = textBox_GameResult.Text;
53 game.GameName = textBox_GameName.Text;
54 game.GameDateTime = Convert.ToDateTime(dateTimePicker_GameTime.Text);
55 if (!IsEdit)
56 {
57 game.StudentNumber = DataPool.StudentNumber;
58 Context.Games.InsertOnSubmit(game);
59 }
60 Context.SubmitChanges();
61 GridView.DataSource = GetIQueryable.GetGameQueryable(Context);
62 }
63
64 private void button_CancleGame_Click(object sender, EventArgs e)
65 {
66 this.Dispose();
67 }
68 }
69}
70
Code
1using System;
2using System.Linq;
3using System.Windows.Forms;
4
5using StudentManagerV3.DataBase;
6
7namespace StudentManagerV3
8{
9 /**//// <summary>
10 /// 注释没写，同上一个类差不多
11 /// </summary>
12 public partial class Form_Support : Form_Base
13 {
14 private StudentSupport support = new StudentSupport();
15
16 public Form_Support(DataGridView gridview, object entity)
17 : base(entity)
18 {
19 this.GridView = gridview;
20 this.Entity = entity;
21 InitializeComponent();
22 if (IsEdit)
23 {
24 support = entity as StudentSupport;
25 dateTimePicker_SupportTime.Text = support.SupportTime.ToShortDateString();
26 textBox_SupportAmount.Text = support.SupportAmount.ToString();
27 textBox_SupportRemark.Text = support.SupportRemark;
28 textBox_SupportSource.Text = support.SupportFrom;
29 }
30 }
31
32 private void button_AddSupport_Click(object sender, EventArgs e)
33 {
34 AddOrEditInfo();
35 }
36
37 protected override void ConstructEntityInfo()
38 {
39 if (IsEdit)
40 support = (from su in Context.StudentSupports where su.SupportID == ((StudentSupport)Entity).SupportID select su).Single();
41 support.SupportAmount = Convert.ToInt32(textBox_SupportAmount.Text);
42 support.SupportFrom = textBox_SupportSource.Text;
43 support.SupportRemark = textBox_SupportRemark.Text;
44 support.SupportTime = Convert.ToDateTime(dateTimePicker_SupportTime.Text);
45 if (!IsEdit)
46 {
47 support.StudentNumber = DataPool.StudentNumber;
48 Context.StudentSupports.InsertOnSubmit(support);
49 }
50 Context.SubmitChanges();
51 GridView.DataSource = GetIQueryable.GetSupportQueryable(Context);
52 }
53
54 private void button_CancleSupport_Click(object sender, EventArgs e)
55 {
56 this.Dispose();
57 }
58 }
59}
60 多态的实现基本就是子类中调用AddOrEditInfo()的过程了。呵呵 ，就到这里拉
posted @ 2008-04-23 11:15
镜涛 阅读(1521)
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