Delphi 中的哈希表(1): THashedStringList

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

type
TForm1 = class(TForm)
Button1: TButton;
Button2: TButton;
procedure Button1Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

uses
IniFiles; //THashedStringList 来自 IniFiles 单元
var
Hash: THashedStringList;

{ THashedStringList 继承自 TStringList, 只是覆盖了 IndexOf、IndexOfName 两个方法以增加效率;
如果注重效率而不需要太多功能, 可以使用 TStringHash, 它是直接从 TObject 继承的数组链表 }

//建立哈希表
procedure TForm1.FormCreate(Sender: TObject);
var
i: Integer;
begin
Hash := THashedStringList.Create;

for i := 97 to 122 do
begin
Hash.Add(Chr(i) + '=' + IntToStr(i));
end;

ShowMessage(Hash.Text);
{
构建结果:
a=97
b=98
c=99
d=100
e=101
f=102
g=103
h=104
i=105
j=106
k=107
l=108
m=109
n=110
o=111
p=112
q=113
r=114
s=115
t=116
u=117
v=118
w=119
x=120
y=121
z=122
}
end;

//检索哈希表
procedure TForm1.Button1Click(Sender: TObject);
var
i: Integer;
begin
i := Hash.IndexOf('z=122');
ShowMessage(IntToStr(i)); //25

i := Hash.IndexOfName('z');
ShowMessage(IntToStr(i)); //25
end;

//基本操作
procedure TForm1.Button2Click(Sender: TObject);
begin
Hash.Values['a'] := '65'; //赋值
Hash.ValueFromIndex[0] := '65'; //用索引赋值

ShowMessage(Hash.Values['z']); //122, 取值
ShowMessage(Hash.ValueFromIndex[25]);//122, 用索引取值

{其他操作参加 TStringList}
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
Hash.Free;
end;