任意对象数组ArrayList的排序法(可自定义排序字段、排序方向)
ArrayList可以用来组合任何的对象，但其默认的排序是按对象本身值来排序，而不是应用自定义的，因此需要重新修改 ArrayList的Sort方法的 IComparer接口实现。以下是重新写的 IComparer的实现，用了类型反射以做到能适合所有类的排序性能测试：（仅供参考）
配置：PIII 733 384M内存
Windows2000SP4 .net FrameWork 1.1.4322 SP1
ArrayList容纳100个对象，排序时间大约10~20毫秒
ArrayList容纳1000个对象，排序时间大约100毫秒左右
ArrayList容纳10000个对象，排序时间大约1200~1600毫秒
代码：
ReverserClass
实现 IComparer接口的自定义类，其中定义了ArrayList包含的对象的类型 type和需要排序的类型的字段 name
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedBlock.gifpublic class ReverserClass : IComparer https://blog.51cto.com/iteyer/Images/dot.gif {
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif Type type = null;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif string name = string.Empty;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif string direction = "ASC";
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedSubBlock.gif public ReverserClass(Type type, string name, string direction) https://blog.51cto.com/iteyer/Images/dot.gif{
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif this.type = type;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif this.name = name;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif if(direction.Equals("DESC"))
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif this.direction = "DESC";
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockEnd.gif }
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedSubBlock.gif int IComparer.Compare( object x, object y ) https://blog.51cto.com/iteyer/Images/dot.gif{
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif object x1 = this.type.InvokeMember(this.name, BindingFlags.Public | BindingFlags.Instance | BindingFlags.GetProperty, null, x, null);
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif object y1 = this.type.InvokeMember(this.name, BindingFlags.Public | BindingFlags.Instance | BindingFlags.GetProperty, null, y, null);
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif if(direction.Equals("DESC"))
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif Swap(ref x1, ref y1);
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif return( (new CaseInsensitiveComparer()).Compare( x1, y1 ));
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockEnd.gif }
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedSubBlock.gif void Swap(ref object x, ref object y ) https://blog.51cto.com/iteyer/Images/dot.gif{
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif object temp = null;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif temp = x;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif x = y;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif y = temp;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockEnd.gif }
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedBlockEnd.gif }
测试代码
UserClass
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedBlock.gifpublic class UserClass https://blog.51cto.com/iteyer/Images/dot.gif {
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif protected string _name;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif protected int _age;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif protected string _address;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedSubBlock.gif public UserClass(string _name, int _age, string _address) https://blog.51cto.com/iteyer/Images/dot.gif{
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif this._name = _name;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif this._age = _age;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif this._address = _address;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockEnd.gif }
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedSubBlock.gif public string Name https://blog.51cto.com/iteyer/Images/dot.gif{
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedSubBlock.gif get https://blog.51cto.com/iteyer/Images/dot.gif{ return _name; }
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedSubBlock.gif set https://blog.51cto.com/iteyer/Images/dot.gif{ _name = value; }
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockEnd.gif }
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedSubBlock.gif public int Age https://blog.51cto.com/iteyer/Images/dot.gif{
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedSubBlock.gif get https://blog.51cto.com/iteyer/Images/dot.gif{ return _age; }
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedSubBlock.gif set https://blog.51cto.com/iteyer/Images/dot.gif{ _age = value; }
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockEnd.gif }
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedSubBlock.gif public string Address https://blog.51cto.com/iteyer/Images/dot.gif{
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedSubBlock.gif get https://blog.51cto.com/iteyer/Images/dot.gif{ return _address; }
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedSubBlock.gif set https://blog.51cto.com/iteyer/Images/dot.gif{ _address = value; }
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedSubBlockEnd.gif }
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedBlockEnd.gif}
main
其中ReverserClass reverser = new ReverserClass(user.GetType(), " Name " ); 中的要传递ArrayList数组中的对象的类型和需要作为排序依据的字段名称！
https://blog.51cto.com/iteyer/Images/OutliningIndicators/None.gif static void Main( string [] args)
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedBlockStart.gifhttps://blog.51cto.com/iteyer/Images/OutliningIndicators/ContractedBlock.gif https://blog.51cto.com/iteyer/Images/dot.gif {
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif UserClass user;
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif ArrayList ar = new ArrayList();
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif user = new UserClass("1", 1, "1");
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif ar.Add(user);
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif user = new UserClass("9", 9, "9");
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif ar.Add(user);
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif user = new UserClass("4", 4, "4");
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif ar.Add(user);
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif user = new UserClass("3", 3, "3");
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif ar.Add(user);
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif user = new UserClass("6", 6, "6");
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif ar.Add(user);
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif Console.WriteLine(https://blog.51cto.com/iteyer/Images/dot.gif);
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif ReverserClass reverser = new ReverserClass(user.GetType(), "Name", "DESC");
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif ar.Sort(reverser);
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif Console.WriteLine(https://blog.51cto.com/iteyer/Images/dot.gif);
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif
https://blog.51cto.com/iteyer/Images/OutliningIndicators/InBlock.gif
https://blog.51cto.com/iteyer/Images/OutliningIndicators/ExpandedBlockEnd.gif }
文档来源：51CTO技术博客https://blog.51cto.com/iteyer/3238392
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