1: //需求1: 將CheckBoxList中選取的項目Value用分號串起來
2:
3: //老方法，跑迴圈，第一筆資料不加;
4: StringBuilder sb = new StringBuilder();
5: foreach (ListItem item in CheckBoxList1.Items)
6: { 7: if (!item.Selected) continue;
8: if (sb.Length > 0) sb.Append(";"); 9: sb.Append(item.Value);
10: }
11: Response.Write(sb.ToString());
12:
13: //改良法1，不花功夫決定加不加分號，最後再移除多餘的分號
14: sb = new StringBuilder();
15: foreach (ListItem item in CheckBoxList1.Items)
16: if (item.Selected)
17: sb.AppendFormat("{0};", item.Value); 18: //直接用TrimEnd移掉多餘的分號
19: Response.Write(sb.ToString().TrimEnd(';')); 20:
21: //改良法2，利用Join
22: List<string> lst = new List<string>();
23: foreach (ListItem item in CheckBoxList1.Items)
24: if (item.Selected) lst.Add(item.Value);
25: //string.Join會將陣列組裝成字串
26: Response.Write(string.Join(";", lst.ToArray())); 27:
28: //需求2 將數字補零至四位
29: int i = 5;
30:
31: //VBScript常見做法
32: string s = "0000" + i.ToString();
33: //VB.NET還可用RIGHT$
34: Response.Write(s.Substring(s.Length - 4));
35:
36: //Format會簡單一些
37: s = string.Format("{0:0000}", i); 38:
39: //PadLeft也佷酷，還可以用在非數字上
40: s = i.ToString().PadLeft(4, '0');
Update 2007-11-13 這裡也可以寫成i.ToString("0000"); 謝謝evakey補充