小甲鱼Delphi教程37课《读写修改记录型文件》源码

 1 unit Unit1;
 2 
 3 interface
 4 
 5 uses
 6   Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
 7   Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.ExtCtrls;
 8 
 9 type
10   TForm1 = class(TForm)
11     LabeledEdit1: TLabeledEdit;
12     LabeledEdit2: TLabeledEdit;
13     Button1: TButton;
14     Button2: TButton;
15     procedure FormCreate(Sender: TObject);
16     procedure FormClose(Sender: TObject; var Action: TCloseAction);
17     procedure Button1Click(Sender: TObject);
18     procedure Button2Click(Sender: TObject);
19   private
20     { Private declarations }
21   public
22     { Public declarations }
23   end;
24 
25 var
26   Form1: TForm1;
27 
28 implementation
29 type
30   Lady=record
31     num: Byte;
32     name: string[10];
33   end;
34 var
35   VFlady: file of Lady;
36   v1:Lady;
37 {$R *.dfm}
38 
39 procedure TForm1.Button1Click(Sender: TObject);
40 begin
41   v1.num:=StrToInt(LabeledEdit1.text);
42   v1.name:=LabeledEdit2.Text;
43   Seek(VFlady,filesize(vflady));
44   write(VFlady,v1);
45   ShowMessage(IntToStr(FileSize(VFlady)));
46 end;
47 
48 procedure TForm1.Button2Click(Sender: TObject);
49 var
50   n:Integer;
51 begin
52   n:=StrToInt(inputbox('提醒！','输入需要修改的编号','1'));
53   Seek(VFlady,n-1);
54   read(VFlady,v1);
55   v1.name:=inputbox('提醒！','输入需要修改的编号','姓名');
56   Seek(VFlady,n-1);
57   write(vflady,v1);
58 
59 
60 end;
61 
62 procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
63 begin
64 CloseFile(VFlady);
65 end;
66 
67 procedure TForm1.FormCreate(Sender: TObject);
68 var
69   curdir:string;
70 begin
71 GetDir(0,curdir);
72 AssignFile(VFlady,curdir+'\wocao.dat');
73 if FileExists(curdir+'\wocao.dat') then
74   Reset(VFlady)
75 else
76   Rewrite(vflady);
77 
78 
79 end;
80 
81 end.