（7）序列化與壓縮(2)

為每種需要傳遞的參數去定義一個TSerialableComponent，也是比較麻煩，用Key/Value的字典更簡潔。

TStringList就是一個可以作為Key/Value來使用的字典，通過Values(Key)函數來讀寫值，通過Text屬性來序列化和還原序列化。但是對複雜資料，如Byte Array，可能會遇到麻煩。

下面是自己實現的一個Dictionary，可序列化和還原序列化：

  TKeyValueList=class  private    FList:TacroHashList;    function GetCount: integer;    function _Clear(AUserData: Pointer; const AStr: string; var APtr: Pointer): Boolean;    function _Serialize(AUserData: Pointer; const AStr: string; var APtr: Pointer): Boolean;  public    procedure Add(Key:string;Value:Variant);    procedure Delete(Key:string);    function  TryGetValue(Key:string;out Value:Variant):Boolean;    function  GetValue(Key:string):Variant;    procedure Clear;virtual;  public    constructor Create(ACapacity:integer=256);virtual;    destructor Destroy;override;    property Count:integer read GetCount;  public    //序列化成Byte Array    function SerializeToVariant:Variant;virtual;    procedure UnSerializeFromVariant(AData:Variant);virtual;  end;{ TKeyValueList }procedure TKeyValueList.Add(Key: string; Value: Variant);var  P:PVariant;begin  if FList.Find(Key,P) then    P^:=Value  else  begin    New(P);    P^:=Value;    FList.Add(Key,P);  end;end;procedure TKeyValueList.Clear;begin  FList.IterateMethod(nil,_Clear);  FList.Clear;end;constructor TKeyValueList.Create(ACapacity: integer);begin  inherited Create;  FList:=TacroHashList.Create(GetMinPrime(ACapacity),StrCompare,StrHash);end;procedure TKeyValueList.Delete(Key: string);var  P:PVariant;begin  if FList.Find(Key,P) then  begin    Dispose(P);    FList.Remove(Key);  end;end;destructor TKeyValueList.Destroy;begin  Clear;  FList.Free;  inherited;end;function TKeyValueList.GetCount: integer;begin  Result:=FList.Count;end;function TKeyValueList.GetValue(Key: string): Variant;var  P:PVariant;begin  if not FList.Find(Key,P) then    raise Exception.CreateFmt('Not found key "%s".',[Key]);  Result:=P^;end;function TKeyValueList.SerializeToVariant: Variant;var  MS:TMemoryStream;  vW:TVariantWriter;begin  MS:=TMemoryStream.Create;  vW:=TVariantWriter.Create(MS);  try    FList.IterateMethod(vW,_Serialize);    Result:=MemoryToVariant(MS);  finally    vW.Free;    MS.Free;  end;end;function TKeyValueList.TryGetValue(Key: string; out Value: Variant): Boolean;var  P:PVariant;begin  Result:=FList.Find(Key,P);  if P<>nil then    Value:=P^;end;procedure TKeyValueList.UnSerializeFromVariant(AData: Variant);var  MS:TMemoryStream;  R:TVariantReader;  Key:string;  Value:Variant;begin  MS:=TMemoryStream.Create;  R:=TVariantReader.Create(MS);  try    VariantToMemory(AData,MS);    FList.Clear;    MS.Position:=0;    while MS.Position<MS.Size do    begin      Key:=R.ReadVariant;      Value:=R.ReadVariant;      Add(Key,Value);    end;  finally    R.Free;    MS.Free;  end;end;function TKeyValueList._Clear(AUserData: Pointer; const AStr: string;  var APtr: Pointer): Boolean;begin  Dispose(PVariant(APtr));end;function TKeyValueList._Serialize(AUserData: Pointer; const AStr: string;  var APtr: Pointer): Boolean;var  W:TVariantWriter;  P:PVariant;begin  Result:=true;  W:=TVariantWriter(AUserData);  P:=APtr;  W.WriteVariant(AStr);  W.WriteVariant(P^);end;