学步园

原来集合里面的对象也能按照某种规则进行排序，只要简单实现IComparer接口；数组的排序也是如此，需要注意的是，集合或数组已有默认的排序方式，数字时默认从小到大，文字时默认按字母顺序。下面是示例：

如果按照指定的规则排序，先制定排序规则（实现IComparer接口）：

using System;<br /> using System.Collections.Generic;<br /> using System.Linq;<br /> using System.Text;<br /> using System.Collections;</p> <p>namespace 对象排序<br /> {<br /> class Employee<br /> {<br /> private int age;</p> <p> public int Age<br /> {<br /> get { return age; }<br /> set { age = value; }<br /> }</p> <p> }</p> <p> class EmployeeSortAdapter : IComparer<Employee><br /> {</p> <p> #region IComparer<Employee> 成员</p> <p> public int Compare(Employee emp1, Employee emp2)<br /> {<br /> Employee e1 = emp1;<br /> Employee e2 = emp2;</p> <p> if (e1.Age == e2.Age)<br /> {<br /> return 0;<br /> }<br /> else if (e1.Age > e2.Age)<br /> {<br /> return 1;<br /> }<br /> else if (e1.Age < e2.Age)<br /> {<br /> return -1;<br /> }<br /> return default(int);<br /> }</p> <p> #endregion<br /> }</p> <p> class EmployeeSortAdapter1 : IComparer<br /> {</p> <p> #region IComparer<Employee> 成员</p> <p> public int Compare(object emp1, object emp2)<br /> {<br /> Employee e1 = (Employee)emp1;<br /> Employee e2 = (Employee)emp2;</p> <p> if (e1.Age == e2.Age)<br /> {<br /> return 0;<br /> }<br /> else if (e1.Age > e2.Age)<br /> {<br /> return 1;<br /> }<br /> else if (e1.Age < e2.Age)<br /> {<br /> return -1;<br /> }<br /> return default(int);<br /> }</p> <p> #endregion<br /> }</p> <p> class NumberSortASCAdapter : IComparer<br /> {</p> <p> #region IComparer<Employee> 成员</p> <p> public int Compare(object emp1, object emp2)<br /> {<br /> if (Convert.ToInt32(emp1) == Convert.ToInt32(emp2))<br /> return 0;<br /> else if (Convert.ToInt32(emp1) > Convert.ToInt32(emp2))<br /> return -1;<br /> else if (Convert.ToInt32(emp1) < Convert.ToInt32(emp2))<br /> return 1;<br /> return default(int);<br /> }</p> <p> #endregion<br /> }<br /> }</p> <p>

调用排序规则的集合方法

private void SortExample()<br /> {</p> <p> try<br /> {<br /> Employee[] employees = new Employee[6];<br /> for (int i = 0; i < 6; i++)<br /> {<br /> employees[i] = new Employee();<br /> }</p> <p> int[] intTest = new int[100];<br /> Random ro = new Random(0);<br /> //for (int i = 0; i < 100; i++)<br /> //{<br /> // intTest[i] = ro.Next(0, 99);<br /> //}<br /> StringBuilder sb = new StringBuilder();<br /> //foreach (int i in intTest)<br /> //{<br /> // sb.AppendLine(Convert.ToString(i));<br /> //}</p> <p> Hashtable hashtable = new Hashtable();<br /> Random rm = new Random();<br /> int RmNum = 100;<br /> for (int i = 0; hashtable.Count < RmNum; i++)<br /> {<br /> int nValue = rm.Next(0, 100);<br /> if (!hashtable.ContainsValue(nValue))<br /> {<br /> hashtable.Add(nValue, nValue);<br /> intTest[hashtable.Count-1] = nValue;<br /> sb.Append(Convert.ToString(nValue) + "|");<br /> }<br /> }<br /> sb.Append("数量：" + Convert.ToString(hashtable.Count));<br /> textBox1.Text = sb.ToString();<br /> sb = new StringBuilder();</p> <p> Array.Sort(intTest,new NumberSortASCAdapter());<br /> foreach (int item in intTest)<br /> {<br /> sb.Append(Convert.ToString(item) + "|");<br /> }<br /> sb.Append("数量：" + Convert.ToString(hashtable.Count));<br /> textBox2.Text = sb.ToString();<br /> employees[0].Age = 12;<br /> employees[1].Age = 34;<br /> employees[2].Age = 64;<br /> employees[3].Age = 53;<br /> employees[4].Age = 2;<br /> employees[5].Age = 1;</p> <p> ArrayList al = new ArrayList();<br /> al.Add(employees[0]);<br /> al.Add(employees[1]);<br /> al.Add(employees[2]);<br /> al.Add(employees[3]);<br /> al.Add(employees[4]);<br /> al.Add(employees[5]);<br /> al.Sort(new EmployeeSortAdapter1());<br /> //Array.Sort(employees, new EmployeeSortAdapter());<br /> Array.Sort(employees, new EmployeeSortAdapter1());</p> <p> //foreach (Employee emp in employees)<br /> //{<br /> // sb.AppendLine(Convert.ToString(emp.Age));<br /> //}<br /> //foreach (Employee emp in al)<br /> //{<br /> // sb.AppendLine(Convert.ToString(emp.Age));<br /> //}<br /> Console.Read();<br /> }<br /> catch (Exception ex)<br /> {<br /> MessageBox.Show(ex.Message + ex.StackTrace);<br /> }</p> <p>}