delphi 中的哈希表: 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;

end.

Delphi 中的哈希表(2): TStringHash

unit Unit1;

interface

uses

Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

Dialogs, StdCtrls;

type

TForm1 = class(TForm)

Button1: TButton;

Button2: TButton;

procedure FormCreate(Sender: TObject);

procedure FormDestroy(Sender: TObject);

procedure Button1Click(Sender: TObject);

procedure Button2Click(Sender: TObject);

private

{ Private declarations }

public

{ Public declarations }

end;

var

Form1: TForm1;

implementation

{$R *.dfm}

uses

IniFiles; //TStringHash 来自 IniFiles 单元

var

Hash: TStringHash;

{ TStringHash 的功能非常简单, 如果需要更多功能应该使用: THashedStringList

TStringHash 与 THashedStringList、TStringList 最大的不同是:

TStringHash 的 Key 必须是 String; Value 必须是 Integer.

如果这不适合你的要求, 建一个 TMyHash 也不是难事 }

//建立哈希表

procedure TForm1.FormCreate(Sender: TObject);

var

i: Integer;

begin

Hash := TStringHash.Create(26); //26 是表的初始大小, 可以省略使用默认值256

for i := 65 to 90 do

begin

Hash.Add(Chr(i),i); //如果表不够大,会自动增加的

end;

//读取

procedure TForm1.Button1Click(Sender: TObject);

var

num: Integer;

begin

num := Hash.ValueOf('Z');

ShowMessage(IntToStr(num)); //90

end;

//修改、删除、清空

procedure TForm1.Button2Click(Sender: TObject);

begin

Hash.Modify('Z',100); //修改

Hash.Remove('A'); //删除

Hash.Clear; //清空

{没了, 就这些功能}

end;

procedure TForm1.FormDestroy(Sender: TObject);

begin

Hash.Free;

end;

end.

https://www.cnblogs.com/del/archive/2007/12/18/1003845.html

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