【搞定】[请求]想问一下X3平台有HashTable吗？**

vinda · 发表于 2007-4-26 15:52:02

想问问各位，X3平台有没有类似Java 中的Hashtable 类的功能？能够象这样Put(Key, Value) 存放Key 和 Value ？谢谢！

vinda · 发表于 2007-4-26 16:07:54

我刚才在网上找到一个Delphi下的代码，但是我把它建在公共资源里的时候，编译不过去，改了之后还是编译不过去，问问高手这段代码我们能不能利用一下，在X3下为我们所用？
代码部分如下：
Hashtable.pas
--------------------------------------------------------------------------------
unit Hashtable;

interface

uses SysUtils, Classes;

type
   { THashTable }

   PPHa****em = ^PHa****em;
   PHa****em = ^THa****em;
   THa****em = record
   Next: PHa****em;
   Key: string;
   Value: String;
   end;

   THashTable = class
   private
   Buckets: array of PHa****em;
   protected
   function Find(const Key: string): PPHa****em;
   function HashOf(const Key: string): Cardinal; virtual;
   public
   constructor Create(Size: Integer = 256);
   destructor Destroy; override;
   procedure Put(const Key: string; Value: String);
   procedure Clear;
   procedure Remove(const Key: string);
   function Modify(const Key: string; Value: String): Boolean;
   function Get(const Key: string): String;
   end;

implementation

{ THashTable }

procedure THashTable.Put(const Key: string; Value: String);
var
   Hash: Integer;
   Bucket: PHa****em;
begin
   Hash := HashOf(Key) mod Cardinal(Length(Buckets));
   New(Bucket);
   Bucket^.Key := Key;
   Bucket^.Value := Value;
   Bucket^.Next := Buckets[Hash];
   Buckets[Hash] := Bucket;
end;

procedure THashTable.Clear;
var
   I: Integer;
   P, N: PHa****em;
begin
   for I := 0 to Length(Buckets) - 1 do
   begin
   P := Buckets[I];
   while P <> nil do
   begin
      N := P^.Next;
      Dispose(P);
      P := N;
   end;
   Buckets[I] := nil;
   end;
end;

constructor THashTable.Create(Size: Integer);
begin
   inherited Create;
   SetLength(Buckets, Size);
end;

destructor THashTable.Destroy;
begin
   Clear;
   inherited;
end;

function THashTable.Find(const Key: string): PPHa****em;
var
   Hash: Integer;
begin
   Hash := HashOf(Key) mod Cardinal(Length(Buckets));
   Result := @Buckets[Hash];
   while Result^ <> nil do
   begin
   if Result^.Key = Key then
      Exit
   else
      Result := @Result^.Next;
   end;
end;

function THashTable.HashOf(const Key: string): Cardinal;
var
   I: Integer;
begin
   Result := 0;
   for I := 1 to Length(Key) do
   Result := ((Result shl 2) or (Result shr (SizeOf(Result) * 8 - 2))) xor
      Ord(Key[I]);
end;

function THashTable.Modify(const Key: string; Value: String): Boolean;
var
   P: PHa****em;
begin
   P := Find(Key)^;
   if P <> nil then
   begin
   Result := True;
   P^.Value := Value;
   end
   else
   Result := False;
end;

procedure THashTable.Remove(const Key: string);
var
   P: PHa****em;
   Prev: PPHa****em;
begin
   Prev := Find(Key);
   P := Prev^;
   if P <> nil then
   begin
   Prev^ := P^.Next;
   Dispose(P);
   end;
end;

function THashTable.Get(const Key: string): String;
var
   P: PHa****em;
begin
   P := Find(Key)^;
   if P <> nil then
   Result := P^.Value else
   Result := '';
end;

end.

本程序在Delphi 6.0下通过。

vinda · 发表于 2007-4-26 16:10:15

不明白我贴上去的代码怎么都变成***号了，再来贴一遍：

unit Hashtable;

interface

uses SysUtils, Classes;

type
   { THashTable }

   PPHa****em = ^PHa****em;
   PHa****em = ^THa****em;
   THa****em = record
   Next: PHa****em;
   Key: string;
   Value: String;
   end;

   THashTable = class
   private
   Buckets: array of PHa****em;
   protected
   function Find(const Key: string): PPHa****em;
   function HashOf(const Key: string): Cardinal; virtual;
   public
   constructor Create(Size: Integer = 256);
   destructor Destroy; override;
   procedure Put(const Key: string; Value: String);
   procedure Clear;
   procedure Remove(const Key: string);
   function Modify(const Key: string; Value: String): Boolean;
   function Get(const Key: string): String;
   end;

implementation

{ THashTable }

procedure THashTable.Put(const Key: string; Value: String);
var
   Hash: Integer;
   Bucket: PHa****em;
begin
   Hash := HashOf(Key) mod Cardinal(Length(Buckets));
   New(Bucket);
   Bucket^.Key := Key;
   Bucket^.Value := Value;
   Bucket^.Next := Buckets[Hash];
   Buckets[Hash] := Bucket;
end;

procedure THashTable.Clear;
var
   I: Integer;
   P, N: PHa****em;
begin
   for I := 0 to Length(Buckets) - 1 do
   begin
   P := Buckets[I];
   while P <> nil do
   begin
      N := P^.Next;
      Dispose(P);
      P := N;
   end;
   Buckets[I] := nil;
   end;
end;

constructor THashTable.Create(Size: Integer);
begin
   inherited Create;
   SetLength(Buckets, Size);
end;

destructor THashTable.Destroy;
begin
   Clear;
   inherited;
end;

function THashTable.Find(const Key: string): PPHa****em;
var
   Hash: Integer;
begin
   Hash := HashOf(Key) mod Cardinal(Length(Buckets));
   Result := @Buckets[Hash];
   while Result^ <> nil do
   begin
   if Result^.Key = Key then
      Exit
   else
      Result := @Result^.Next;
   end;
end;

function THashTable.HashOf(const Key: string): Cardinal;
var
   I: Integer;
begin
   Result := 0;
   for I := 1 to Length(Key) do
   Result := ((Result shl 2) or (Result shr (SizeOf(Result) * 8 - 2))) xor
      Ord(Key[I]);
end;

function THashTable.Modify(const Key: string; Value: String): Boolean;
var
   P: PHa****em;
begin
   P := Find(Key)^;
   if P <> nil then
   begin
   Result := True;
   P^.Value := Value;
   end
   else
   Result := False;
end;

procedure THashTable.Remove(const Key: string);
var
   P: PHa****em;
   Prev: PPHa****em;
begin
   Prev := Find(Key);
   P := Prev^;
   if P <> nil then
   begin
   Prev^ := P^.Next;
   Dispose(P);
   end;
end;

function THashTable.Get(const Key: string): String;
var
   P: PHa****em;
begin
   P := Find(Key)^;
   if P <> nil then
   Result := P^.Value else
   Result := '';
end;

end.

vinda · 发表于 2007-4-26 16:11:58

不知道为啥，还是不行，****号部分是‘****’。

vinda · 发表于 2007-4-26 16:13:46

就是贴不上去，是's' 'h' 'I' 't'，这回总行了吧？

alang · 发表于 2007-4-27 10:13:55

平台上不支持指针操作，所以以上代码肯定编译不过的，有两种方法解决
1 当作第三方控件导入平台使用
2 读懂以上程序，不要用指针和指针数组，用TList来代替，在平台上重写以上代码

vinda · 发表于 2007-4-27 11:07:17

好的，我试试吧，谢谢你了！

atiger · 发表于 2007-4-29 12:01:56

？？

Akon · 发表于 2007-9-15 16:21:55

由于楼主长时间未跟贴,此帖先结,有问题请开新帖.

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