编程可运行文件需要什么（9.键盘鼠标和文件编程）
编程可运行文件需要什么（9.键盘鼠标和文件编程）示例主要组件及属性：表单窗体：procedure Read (F v1[ v2 ...vn]);5.2写入有类型文件调用 Write 过程可以将数据写入到文件中，格式如下：procedure Write(F v1 v2 ...vn);5.3有类型文件的基本操作返回文件指针的当前位置function FilePos(var F): Longint;返回文件的大小function FileSize(var F): Integer;移动文件指针的位置procedure Seek(var F; n: Longint);截去当前位置后的所有数据procedure Truncate(var F);5.4有类型文件编程示例示例：编写一个学生记录表的保存和读取程序。界面如下如：主窗体：
5.有类型文件编程有类型文件时一种具有一定数据类型的文件，是由指定数据组成。读写过程中所操作的对象是一个指定类型的数据。有类型文件的声明格式：
Type <文件类型> = File of type;
其中，type 可以是各种数据类型。
有类型数据文件可以确定文件指针在文件中的位置，可以随机存取。
5.1读取有类型文件有类型文件读写可以同时进行。读取有类型文件通过调用 Read 过程来进行操作，格式如下：
procedure Read (F v1[ v2 ...vn]);5.2写入有类型文件
调用 Write 过程可以将数据写入到文件中，格式如下：
procedure Write(F v1 v2 ...vn);5.3有类型文件的基本操作
- 返回文件指针的当前位置
function FilePos(var F): Longint;
- 返回文件的大小
function FileSize(var F): Integer;
- 移动文件指针的位置
procedure Seek(var F; n: Longint);
- 截去当前位置后的所有数据
procedure Truncate(var F);5.4有类型文件编程示例
示例：编写一个学生记录表的保存和读取程序。界面如下如：
主窗体：
表单窗体：
示例主要组件及属性：
|
组件 |
属性 |
值 |
说明 |
|
Panel1 |
Align |
alTop |
对齐到顶部，其上存放按钮 |
|
StringGrid1 |
Align |
alClient |
充满可显示区域 |
|
ColCount |
7 |
7列 | |
|
RowCount |
1 |
刚打开窗体时只显示一行，标题行 | |
|
Options/goRowSelect |
True |
可选中行 | |
|
SaveDialog1 |
文件保存对话框 | ||
|
OpenDialog1 |
文件打开对话框 |
主窗体示例代码：
unit Unit1;
interface
uses
Winapi.Windows Winapi.Messages System.SysUtils System.Variants System.Classes Vcl.Graphics
Vcl.Controls Vcl.Forms Vcl.Dialogs Vcl.Grids Vcl.ExtCtrls Vcl.StdCtrls;
type
TForm1 = class(TForm)
Panel1: TPanel;
StringGrid1: TStringGrid;
Button1: TButton;
Button2: TButton;
Button3: TButton;
Button4: TButton;
Button5: TButton;
Button6: TButton;
SaveDialog1: TSaveDialog;
OpenDialog1: TOpenDialog;
procedure Button3Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure Button6Click(Sender: TObject);
procedure Button4Click(Sender: TObject);
procedure Button5Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
procedure WriteStudent(RowIndex: integer);
public
{ Public declarations }
end;
StudentRecord = record
sn name sex: string[32];
chinese math english: double;
end;
var
Form1: TForm1;
// student 变量只用于与 Form2 交换数据
student: StudentRecord;
F: file of StudentRecord;
implementation
{$R *.dfm}
uses Unit2;
procedure TForm1.WriteStudent(RowIndex: Integer);
begin
with StringGrid1 do
begin
Cells[0 RowIndex] := inttostr(RowIndex);
Cells[1 RowIndex] := student.sn;
Cells[2 RowIndex] := student.name;
Cells[3 RowIndex] := student.sex;
Cells[4 RowIndex] := floattostr(student.chinese);
Cells[5 RowIndex] := floattostr(student.math);
Cells[6 RowIndex] := floattostr(student.english);
end;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
with StringGrid1 do
begin
Cells[0 0] := '';
Cells[1 0] := '学号';
Cells[2 0] := '姓名';
Cells[3 0] := '性别';
Cells[4 0] := '语文';
Cells[5 0] := '数学';
Cells[6 0] := '英语';
end;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
FileName: String;
RowIndex: integer;
s: StudentRecord;
begin
if OpenDialog1.Execute then
begin
StringGrid1.RowCount := 1;
FileName := OpenDialog1.FileName;
AssignFile(F FileName);
Reset(F);
while not Eof(F) do
begin
Read(F s);
RowIndex := StringGrid1.RowCount;
StringGrid1.RowCount := StringGrid1.RowCount 1;
with StringGrid1 do
begin
Cells[0 RowIndex] := inttostr(RowIndex);
Cells[1 RowIndex] := s.sn;
Cells[2 RowIndex] := s.name;
Cells[3 RowIndex] := s.sex;
Cells[4 RowIndex] := floattostr(s.chinese);
Cells[5 RowIndex] := floattostr(s.math);
Cells[6 RowIndex] := floattostr(s.english);
end;
end;
CloseFile(F);
end;
end;
procedure TForm1.Button2Click(Sender: TObject);
var
FileName: String;
RowIndex: integer;
s: StudentRecord;
begin
// 保存
if StringGrid1.RowCount < 2 then
begin
ShowMessage('表格中没有数据，不能保存！');
Exit;
end;
if SaveDialog1.Execute then
begin
FileName := SaveDialog1.FileName;
AssignFile(F FileName);
Rewrite(F);
for RowIndex := 1 to StringGrid1.RowCount - 1 do
begin
with StringGrid1 do
begin
s.sn := Cells[1 RowIndex];
s.name := Cells[2 RowIndex];
s.sex := Cells[3 RowIndex];
s.chinese := strtofloat(Cells[4 RowIndex]);
s.math := strtofloat(Cells[5 RowIndex]);
s.english := strtofloat(Cells[6 RowIndex]);
end;
Write(F s);
end;
CloseFile(F);
end;
end;
procedure TForm1.Button3Click(Sender: TObject);
var
RowIndex: integer;
begin
// 添加记录
with student do
begin
sn := '';
name := '';
sex := '';
chinese := 0;
math := 0;
english := 0;
end;
if Form2.ShowModal = mrOk then
begin
StringGrid1.RowCount := StringGrid1.RowCount 1;
RowIndex := StringGrid1.RowCount - 1;
WriteStudent(RowIndex);
end;
end;
procedure TForm1.Button4Click(Sender: TObject);
var
RowIndex: integer;
begin
// 编辑
RowIndex := StringGrid1.Selection.Top;
if RowIndex <> 0 then
begin
with StringGrid1 do
begin
student.sn := Cells[1 RowIndex];
student.name := Cells[2 RowIndex];
student.sex := Cells[3 RowIndex];
student.chinese := strtofloat(Cells[4 RowIndex]);
student.math := strtofloat(Cells[5 RowIndex]);
student.english := strtofloat(Cells[6 RowIndex]);
end;
if Form2.ShowModal = mrOk then
begin
WriteStudent(RowIndex);
end;
end
else
ShowMessage('请选择要编辑的记录！');
end;
procedure TForm1.Button5Click(Sender: TObject);
var
RowIndex i: Integer;
begin
// 删除
if StringGrid1.RowCount < 2 then
Exit;
RowIndex := StringGrid1.Selection.Top;
if RowIndex <> 0 then
begin
for i := RowIndex to StringGrid1.RowCount - 1 do
begin
StringGrid1.Rows[i] := StringGrid1.Rows[i 1];
end;
end;
StringGrid1.RowCount := StringGrid1.RowCount - 1;
end;
procedure TForm1.Button6Click(Sender: TObject);
begin
// 退出
Close;
end;
end.
表单窗体示例代码：
unit Unit2;
interface
uses
Winapi.Windows Winapi.Messages System.SysUtils System.Variants System.Classes Vcl.Graphics
Vcl.Controls Vcl.Forms Vcl.Dialogs Vcl.StdCtrls Vcl.Mask;
type
TForm2 = class(TForm)
Label1: TLabel;
SnEdit: TEdit;
NameEdit: TEdit;
Label2: TLabel;
Label3: TLabel;
SexBoyRadioButton: TRadioButton;
SexGirlRadioButton: TRadioButton;
Label4: TLabel;
Label5: TLabel;
Label6: TLabel;
Button1: TButton;
Button2: TButton;
ChineseMaskEdit: TMaskEdit;
MathMaskEdit: TMaskEdit;
EnglishMaskEdit: TMaskEdit;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure FormShow(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form2: TForm2;
implementation
{$R *.dfm}
uses Unit1;
procedure TForm2.FormShow(Sender: TObject);
begin
with student do
begin
SnEdit.Text := student.sn;
NameEdit.Text := student.name;
if student.sex = '男' then
SexBoyRadioButton.Checked := true
else
SexGirlRadioButton.Checked := false;
ChineseMaskEdit.Text := floattostr(student.chinese);
MathMaskEdit.Text := floattostr(student.math);
EnglishMaskEdit.Text := floattostr(student.english);
end;
end;
procedure TForm2.Button1Click(Sender: TObject);
begin
// 取消
ModalResult := mrCancel;
end;
procedure TForm2.Button2Click(Sender: TObject);
begin
// 确定
if SnEdit.Text = '' then
ShowMessage('请输入学号！')
else if NameEdit.Text = '' then
ShowMessage('请输入姓名！')
else if ChineseMaskEdit.Text = '' then
ShowMessage('请输入语文成绩！')
else if MathMaskEdit.Text = '' then
ShowMessage('请输入数学成绩！')
else if EnglishMaskEdit.Text = '' then
ShowMessage('请输入英语成绩！')
else
begin
Student.sn := SnEdit.Text;
Student.name := NameEdit.Text;
if SexBoyRadioButton.Checked then
Student.sex := '男'
else
Student.sex := '女';
Student.chinese := strtofloat(ChineseMaskEdit.Text);
Student.math := strtofloat(MathMaskEdit.Text);
Student.english := strtofloat(EnglishMaskEdit.Text);
end;
ModalResult := mrOk;
end;
end.
