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uSingnalMgr.~pas：源码内容
							unit uSingnalMgr;
interface
uses classes,strutils,sysutils;
type
  PSingnalData=^TSingnalData;
  TSingnalData=record
    Caption:ShortString;
    Text:array[0..3000]of AnsiChar;
    Default:Boolean;
  end;
  IIterator=interface
    function HasNext:Boolean; // 是否有下一个元素（遍历完了?）
    function Next:Pointer;  //下一个元素
    procedure Remove;   //删除当前元素
    procedure First;    //定位到第一个元素
  end;
  TIterator=class(TInterfacedObject,IIterator) //可以被任何TList及其子类使用
  private
    FCurIndex:Integer;
    FList:TList;
  public
    constructor Create(Container:TList);
    function HasNext:Boolean;
    function Next:Pointer;
    procedure Remove;
    procedure First;
  end;
  TSingnalList=class(TList)
  protected
    procedure Notify(Ptr: Pointer; Action: TListNotification); Override;
  public
    function NewSingnal:PSingnalData;  //使用此方法分配的内存不用自己释放，该类会自动管理。
  end;
  TSingnalMgr=class(TObject)
  private
    List:TSingnalList;
    FIterator:IIterator;
  protected
    procedure SaveToFile; virtual;abstract;
    procedure LoadFromFile;virtual;abstract;
  public
    constructor Create;
    destructor Destroy; override;
    Function Add:PSingnalData;
    procedure Remove(Index:Integer);
    function Get(Index:Integer):PSingnalData;
    property Iterator:IIterator read FIterator;
  end;
  TAppSingnalMgr=class(TSingnalMgr)
  public
    procedure SaveToFile; override;
    procedure LoadFromFile;  override;
  end;
implementation
uses uCommon, NativeXml, NativeXmlObjectStorage, uMyXml;
{ TSingnalList }
function TSingnalList.NewSingnal: PSingnalData;
begin
  GetMem(Result,Sizeof(TSingnalData));
  FillChar(Result^,Sizeof(TSingnalData),0);
end;
procedure TSingnalList.Notify(Ptr: Pointer; Action: TListNotification);
begin
  case Action of
    lnAdded:;
    lnExtracted:;
    lnDeleted:
      if Ptr<>nil then
      begin
        FreeMem(PSingnalData(Ptr));
        ${warning off}
        ptr:=nil;
        ${warning on}
      end;
  end;
end;
{ TSingnalMgr }
function TSingnalMgr.Add: PSingnalData;
begin
  Result:=List.NewSingnal;
  List.Add(Result);
end;
constructor TSingnalMgr.Create;
begin
  List:=TSingnalList.Create;
  FIterator:=TIterator.Create(Self.List);
end;
destructor TSingnalMgr.Destroy;
begin
  IIterator(FIterator):=nil;
  List.Free;
  inherited;
end;
function TSingnalMgr.Get(Index: Integer): PSingnalData;
begin
  Result:=PSingnalData(List[index]);
end;
procedure TSingnalMgr.Remove(Index: Integer);
begin
  List.Delete(Index);
end;
{ TAppSingnalMgr }
procedure TAppSingnalMgr.LoadFromFile;
var
  xml:TAppXml;
  L:TList;
  I:integer;
  PData:PSingnalData;
  Str:String;
begin
  xml:=TAppXml.Create;
  try
    if xml.Root.FindNode('Singnals')=nil then exit;
    L:=TList.Create;
    try
      xml.Root.FindNode('Singnals').NodesByName('Singnal',L);
      for I:=0 to L.Count-1 do
      begin
        PData:=List.NewSingnal;
        PData.Caption:=TXmlNode(L[I]).AttributeByName['Caption']; //
        PData.Default:=StrToBoolDef(TXmlNode(L[I]).AttributeByName['Default'],False);
        Str:=TXmlNode(L[I]).ReadString('Text','');
        if length(Str)>0 then
          System.Move(Str[1],PData.Text,length(Str));
        List.Add(PData);
      end;
    finally
      L.free;
    end;
  finally
    xml.Free;
  end;
end;
procedure TAppSingnalMgr.SaveToFile;
var
  xml:TAppXml;
  N:TXmlNode;
  I:integer;
  PData:PSingnalData;
begin
  xml:=TAppXml.Create;
  try
    if xml.Root.FindNode('Singnals')<>nil then
      xml.Root.FindNode('Singnals').Delete;
    N:=xml.Root.NodeNew('Singnals');
    for I:=0 to List.Count-1 do
    begin
      PData:=PSingnalData(List[I]);
      with N.NodeNew('Singnal')do
      begin
        AttributeByName['Caption']:=PData.Caption;
        WriteString('Text',PData.Text);
        AttributeByName['Default']:=BoolToStr(PData.Default);
      end;
    end;
  finally
    xml.Free;
  end;
end;
{ TSingnalMgrIterator }
constructor TIterator.Create(Container:TList);
begin
  if Container=nil then Raise Exception.Create(' Value of Container DON''T allow  nil ');
  FList:=Container;
  FCurIndex:=0;
end;
procedure TIterator.First;
begin
  FCurIndex:=0;
end;
function TIterator.HasNext: Boolean;
begin
  Result:=FCurIndex<FList.Count;
end;
function TIterator.Next: Pointer;
begin
  if HasNext then
  begin
    Result:=FList[FCurIndex];
    Inc(FCurIndex);
  end
  else  Raise Exception.Create('Next Element DO NOT Exsit.Index Out Of Bounds!');
end;
procedure TIterator.Remove;
begin
  if FCurIndex>=FList.Count then Raise Exception.Create('Index Out Of Bounds!');
  FList.Remove(FList[FCurIndex]);
end; 
end.

						