处理之文本文件

时间:2023-02-11 09:12:56
处理之文本文件处理之文本文件
 1 unit Unit1;
 2 
 3 interface
 4 
 5 uses
 6   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
 7   Dialogs, StdCtrls;
 8 
 9 type
10   TForm1 = class(TForm)
11     Button1: TButton;
12     Button2: TButton;
13     Button3: TButton;
14     procedure Button1Click(Sender: TObject);
15     procedure Button2Click(Sender: TObject);
16     procedure Button3Click(Sender: TObject);
17   private
18     { Private declarations }
19   public
20     { Public declarations }
21   end;
22 
23 var
24   Form1: TForm1;
25 
26 implementation
27 
28 var
29   F: TextFile;
30   FileName: string = 'c:/A.txt';
31 
32 
33 {$R *.dfm}
34 
35 //向文本文件写入内容
36 procedure TForm1.Button1Click(Sender: TObject);
37 begin
38   AssignFile(F,FileName);
39   Rewrite(F);        //重写(覆盖)已存在的文件
40   Writeln(F,'one');  //写入一行
41   Writeln(F,'two');
42   CloseFile(F);
43 end;
44 
45 //读取文本文件内容
46 procedure TForm1.Button2Click(Sender: TObject);
47 var
48   str:string;
49 begin
50   AssignFile(F,FileName);
51   Reset(F);         //以只读方式打开文本文件
52   while not Eof(F) do      //循环文本文件,判断是否到尾部
53   begin
54     Readln(F,str);         //读取一行
55     ShowMessage(str);
56   end;
57 end;
58 
59 //向文本文件追加内容
60 procedure TForm1.Button3Click(Sender: TObject);
61 begin
62   AssignFile(F,FileName);
63   Append(F);              //打开文件准备追加,指针指向文本末尾
64   Writeln(F, 'three');   //写入一行
65   Writeln(F, 'four');
66   CloseFile(F);
67 end;
68 
69 end.
View Code