Использование TFileStream

Delphi , Компоненты и Классы , Потоки

Оформил: DeeCo
Автор: http://www.swissdelphicenter.ch

type

   TPerson = record
     Name: string[50];
     vorname: string[50];
   end;

   TComputer = record
     Name: string[30];
     cpu: string[30];
   end;

 var
   Form1: TForm1;

   Person: TPerson;
   Computer: TComputer;

   Stream: TFileStream;

 implementation

 {$R *.DFM}

 //Speichern resp. Erstellen von Datei 
//Save or create the file 
procedure TForm1.Button1Click(Sender: TObject);
 begin
   try
     Stream := TFileStream.Create('c:\test.dat', fmOpenReadWrite);
   except
     Stream := TFileStream.Create('c:\test.dat', fmCreate);
   end;

   //2 Eintrage pro Record 
  //save 2 records for TPerson and TComputer 
  Person.Name    := 'Grossenbacher';
   Person.vorname := 'Simon';
   Stream.WriteBuffer(Person, SizeOf(TPerson));

   Person.Name    := 'Stutz';
   Person.vorname := 'Thomas';
   Stream.WriteBuffer(Person, SizeOf(TPerson));

   Computer.Name := 'Delphi';
   Computer.cpu  := 'Intel';
   Stream.WriteBuffer(Computer, SizeOf(TComputer));

   Computer.Name := 'Win';
   Computer.cpu  := 'AMD';
   Stream.WriteBuffer(Computer, SizeOf(TComputer));

   Stream.Free;
 end;

 //ladt alle daten von TPerson in listbox1 und 
//daten von TComputer in Listbox2 

//load records from TPerson to listbox1 and 
//load records from TComputer to listbox2 
procedure TForm1.Button2Click(Sender: TObject);
 var
   i: Integer;
 begin
   try
     // nur lesen offnen 
    //open read only 
    Stream := TFileStream.Create('c:\test.dat', fmOpenRead);
   except
     ShowMessage('Datei konnte nicht geladen werden.');
     Exit;
   end;

   //variable i auf anzahl Eintrage setzen 

  //set variable i to the record count 

  //Einlesen von TPerson 
  //Read records TPerson 
  for i := 2 downto 1 do
   begin
     Stream.ReadBuffer(Person, SizeOf(TPerson));
     Listbox1.Items.Add(Person.vorname + ' ' + Person.Name);
   end;

   //Einlesen von TComputer 
  //Read Records TComputer 
  for i := 2 downto 1 do
   begin
     Stream.ReadBuffer(Computer, SizeOf(TComputer));
     Listbox2.Items.Add(Computer.Name + ' ' + Computer.cpu);
   end;

   Stream.Free;
 end;

Статья Использование TFileStream раздела Компоненты и Классы Потоки может быть полезна для разработчиков на Delphi и FreePascal.

Комментарии и вопросы

:: Главная :: Потоки ::