FieldByNameのような関数を自作したい (ID:28804)

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書き込みは一切考慮してませんでしたので書き込みできるように修正しました

unit MyTable;

interface

uses
  SysUtils, Classes;

type

TMyTable = class;

TMyField = class(TComponent)
  private
    FMyTable : TMyTable;
    FAsString : String;
    FIndex : Integer;
  protected
    procedure SetAsString(Value:String);
  public
    constructor Create(AOwner:TComponent);
    destructor Destroy; override;
  published
    property asString :String read fAsString write SetAsString;
    property Index : Integer read FIndex write FIndex;
  end;

TMyTable = class(TComponent)
  private
    FMyField  : TMyField;
    FIndex  : Integer;
    FName : array[0..255] of string;
    FData : array[0..255,0..999] of string;
  protected
    procedure SetNames(Index:Integer;Value:String);
    function  GetNames(Index:Integer):String;
    procedure SetDatas(Index1,Index2:Integer;Value:String);
    function  GetDatas(Index1,Index2:Integer):String;
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    function FieldByName(AName:String):TMyField;
    property Names [Index:Integer] : String read GetNames write SetNames;
    property Datas [Index1,Index2:Integer] : String read GetDatas write SetDatas;
    procedure First;
    procedure Next;
  published
    property Index : Integer read FIndex write FIndex;
  end;

procedure Register;

implementation

constructor TMyField.Create(AOwner:TComponent);
begin
    inherited Create(AOwner);
    FMyTable := TMyTable(AOwner);
end;

destructor TMyField.Destroy;
begin
    inherited Destroy;
end;

procedure TMyField.SetAsString(Value: string);
begin
    FMyTable.Datas[FIndex,FMyTable.Index] := Value;
end;

procedure TMyTable.SetNames(Index: Integer; Value: string);
begin
    FName[Index] := Value;
end;

function TMyTable.GetNames(Index: Integer):String;
begin
    Result := FName[Index];
end;

procedure TMyTable.SetDatas(Index1,Index2: Integer; Value: string);
begin
    FData[Index1,Index2] := Value;
end;

function TMyTable.GetDatas(Index1,Index2: Integer):String;
begin
    Result := FData[Index1,Index2];
end;

procedure TMyTable.First;
begin
    FIndex := 0;
end;

procedure TMyTable.Next;
begin
    Inc(FIndex);
end;

function TMyTable.FieldByName(AName:String):TMyField;
var
    I,J : Integer;
begin
    //ANameに一致するFNameを探す
    J := -1;
    for I:=0 to High(FName) -1 do
    begin
      if FName[I] = AName then J := I;
    end;
    if J <> -1 then
    begin
      //見付かったら
      FMyField.FAsString := Datas[J,Index];
    end
    else
    begin
      //見付からなければ
      FMyField.FAsString := '';
    end;
    FMyField.Index := J;
    Result := FMyField;
end;

constructor TMyTable.Create(AOwner: TComponent);
begin
    inherited Create(AOwner);

FMyField := TMyField.Create(Self);
end;

destructor TMyTable.Destroy;
begin
    FMyField.Free;
    inherited Destroy;
end;

procedure Register;
begin
  RegisterComponents('KHE00221', [TMyTable]);
end;

end.

--------------------
 使い方
--------------------

MyTable1.First;
    MyTable1.FieldByName('Name1').asString := '1111';
    MyTable1.Next;
    MyTable1.FieldByName('Name1').asString := '2222';

MyTable1.First;
    Memo1.Lines.Add(MyTable1.FieldByName('Name1').asString);
    MyTable1.Next;
    Memo1.Lines.Add(MyTable1.FieldByName('Name1').asString);
    MyTable1.Next;
    Memo1.Lines.Add(MyTable1.FieldByName('Name1').asString);

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