有了Table，我们对其继承，实现更符合业务要求的类

1 /**//// <summary>
2/// 描述一个销售报表
3/// </summary>
4 public class SaleReport : Table
5{
6
7public SaleReport(string reportName)
8 : base(reportName, new ColumnCollection())
9{
10
11this.Columns.Add("序号", typeof(int), 0);
12this.Columns.Add("姓名", typeof(string), null);
13this.Columns.Add("商品名称", typeof(string), null);
14this.Columns.Add("日期", typeof(DateTime), null);
15this.Columns.Add("数量", typeof(double), null);
16 }
17
18/**//// <summary>
19/// 报表的名称
20/// </summary>
21 public string Name
22{
23get
24{
25return this.Name;
26 }
27 }
28
29/**//// <summary>
30/// 加入数据
31/// </summary>
32/// <param name="staff"></param>
33/// <param name="commodity"></param>
34/// <param name="cash"></param>
35 public void AddRecord(string staff, string commodity, double cash)
36{
37 Row row = this.NewRow();
38 row["序号"] = this.Rows.Count + 1;
39 row["姓名"] = staff;
40 row["商品名称"] = commodity;
41 row["日期"] = DateTime.Now;
42 row["数量"] = cash;
43
44this.Rows.Add(row);
45 }
46
47/**//// <summary>
48/// 移除数据
49/// </summary>
50/// <param name="index"></param>
51 public void RemoveAt(int index)
52{
53this.Rows.RemoveAt(index);
54 }
55
56/**//// <summary>
57/// 返回销售报表的销售金额
58/// </summary>
59/// <returns></returns>
60 public double GetTotal()
61{
62double cash = 0;
63foreach (Row row in this.Rows)
64{
65 cash += (double)row["数量"];
66 }
67return cash;
68 }
69
70/**//// <summary>
71/// 返回销售报表的销售金额
72/// </summary>
73/// <param name="staff">销售员</param>
74/// <returns></returns>
75 public double GetTotal(string staff)
76{
77double cash = 0;
78foreach (Row row in this.Rows)
79{
80if ((string)row["姓名"] == staff)
81{
82 cash += (double)row["数量"];
83 }
84 }
85return cash;
86 }
87
88 }


SaleReport对外封装了对Table的处理细节，使用SaleReport的用户不会感觉到在使用Table类
1 SaleReport report = new SaleReport("销售台帐");
2 report.AddRecord("Alex", "Phone", 2600);
3 report.AddRecord("Alex", "PC", 4560);
4 report.AddRecord("Alex", "Table", 234);
5 report.AddRecord("Sidney", "Phone", 2100);
6 report.AddRecord("Sidney", "TV", 4500);
7 report.AddRecord("Tom", "oven", 300);
8 report.AddRecord("Leo", "oven", 240);
9
10 report.Print();


运行的结果是
序号 姓名 商品名称 日期 数量

1 Alex Phone 2007-2-13 23:19:27 2600
2 Alex PC 2007-2-13 23:19:27 4560
3 Alex Table 2007-2-13 23:19:27 234
4 Sidney Phone 2007-2-13 23:19:27 2100
5 Sidney TV 2007-2-13 23:19:27 4500
6 Tom oven 2007-2-13 23:19:27 300
7 Leo oven 2007-2-13 23:19:27 240