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delphi写的简单的文件的打开和关闭
unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Button1: TButton; Memo1: TMemo; Label1: TLabel; Edit1: TEdit; Edit2: TEdit; Label2: TLabel; Button2: TButton; procedure Button1Click(Sender: TObject); procedure Button2Click(Sender: TObject); end; //定义记录类型 TRecEmp = record //需要初始化 EmpNo: String[20]; EmpName: String[30]; end; var Form1: TForm1; RecEmp: TRecEmp; //定义一个记录类型的文件变量 FileText: file of TRecEmp; implementation {$R *.dfm} procedure TForm1.Button1Click(Sender: TObject); var last: LongInt; begin RecEmp.EmpNo := trim(Edit1.Text); RecEmp.EmpName := trim(Edit2.Text); try //和某个文件建立链接 AssignFile(FileText,'d:\sql.txt'); //打开一个已经存在的文件 Reset(FileText); last := FileSize(FileText); //将指针移向指定记录 Seek(FileText, last); //写文件 Write(FileText, RecEmp); Edit1.Text := ''; Edit2.Text := ''; CloseFile(FileText); except ReWrite(FileText); end; end; procedure TForm1.Button2Click(Sender: TObject); begin try AssignFile(FileText,'d:\sql.txt'); Reset(FileText); while not Eof(FileText) do begin //读文件 Read(FileText, RecEmp); Memo1.Lines.Add(RecEmp.EmpNo + RecEmp.EmpName); end; finally //关闭文件 CloseFile(FileText); end; end; end.