delphi TFileStream 流操作2

unit frmMain;

interface

uses

Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,

System.Classes, Vcl.Graphics,

Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type

TForm1 = class(TForm)

Button1: TButton;

Memo1: TMemo;

Button2: TButton;

Button3: TButton;

Button4: TButton;

Button5: TButton;

procedure Button1Click(Sender: TObject);

procedure Button2Click(Sender: TObject);

procedure Button3Click(Sender: TObject);

procedure Button4Click(Sender: TObject);

procedure Button5Click(Sender: TObject);

private

{ Private declarations }

public

{ Public declarations }

end;

// 测试数据

TPerson = record

Name: string;

Age: Integer;

end;

var

Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);

var

FileStream: TFileStream;

var

Person: TPerson;

begin

try

FileStream := TFileStream.Create('Person.txt', fmCreate);

// 构造结构体数据

Person.Name := '萧蔷';

Person.Age := 20;

// 写出数据

FileStream.Write(Person, sizeof(Person));

finally

FreeAndNil(FileStream);

end;

procedure TForm1.Button2Click(Sender: TObject);

var

FileStream: TFileStream;

var

Person: TPerson;

begin

try

FileStream := TFileStream.Create('Person.txt', fmOpenRead);

// 设置文件指针的位置

FileStream.Position := 0;

// 无法直接读取结构体

// Self.Memo1.Lines.LoadFromFile('E:\Demo\Person.txt');

// Self.Memo1.Lines.LoadFromStream(FileStream);

// 遍历流中的数据(字节)

while FileStream.Position < FileStream.Size do begin

FileStream.Read(Person, sizeof(Person));

Self.Memo1.Lines.Add(Person.Name + ',' + Person.Age.ToString);

end;

finally

FreeAndNil(FileStream);

end;

procedure TForm1.Button3Click(Sender: TObject);

var

FileStream: TFileStream;

begin

try

FileStream := TFileStream.Create('Memo.txt', fmCreate);

with Self.Memo1 do begin

Lines.Add('Hello');

Lines.Add('World');

Lines.Add('期待B站粉丝过万');

end;

FileStream.WriteComponent(Self.Memo1);

finally

FreeAndNil(FileStream);

end;

procedure TForm1.Button4Click(Sender: TObject);

var

FileStream: TFileStream;

begin

try

FileStream := TFileStream.Create('Memo.txt', fmOpenRead);

FileStream.ReadComponent(Self.Memo1);

finally

FreeAndNil(FileStream);

end;

procedure TForm1.Button5Click(Sender: TObject);

var

FileStream: TFileStream;

begin

Self.Memo1.Lines.LoadFromFile('demo.txt');

// FileStream := TFileStream.Create('E:\Demo\demo.txt', fmOpenRead);

// Self.Memo1.Lines.LoadFromStream(FileStream, TEncoding.utf8);

// FreeAndNil(FileStream);

end;

end.

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