文件：
1、文本文件
2、类型文件
3、无类型文件
1、
var
MyTextFile:TextFile;
begin
{$I-}
AssignFile(MyTextFile,'C:\TextFile.txt');
// Reset(MyTextFile); //??
//Rewrite(MyTextFile);
append(MyTextFile);
try
writeln(MytextFile,'test');
Flush(MyTextFile);
except
ShowMessage('can not write...');
end;
closeFile(MyTextFile);
end;
2、
type
TPerson=packed record
Firstname:string[20];
lastname:string[20];
age:integer;
id:integer;
end;
procedure TForm20.Button2Click(Sender: TObject);
var
//
personfile:file of TPerson;
p,person:TPerson;
begin
AssignFile(Personfile,'c:\person.dat');
// Reset(personfile);//无法写文件？？
rewrite(personfile);
seek(personfile,filesize(personfile));
try
person.Firstname:='tes';
person.lastname:='sta';
person.age:=1;
person.id:=223;
write(personfile,person);
finally
closefile(personfile);
end;
end;
3、
var
untypedfile:file;
buf:array[0..128] of byte;
num:integer;
begin
assignfile(untypedfile,'c:\untypedfile.dat');
Reset(untypedfile);
if fileexists('c:\untypedfile.dat') then
reset(untypedfile)
else
rewrite(untypedfile);
try
seek(untypedfile,filesize(untypedfile));
fillchar(buf,sizeof(buf),'Y');
blockwrite(untypedfile,buf,1,num);
finally
closefile(untypedfile);
end;
end;