集合或数组排序

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

 

调用排序规则的集合方法

 

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