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下面这段程序如果先按Button2再按Button1就会出错，反过来就没事。
怎么解决呢？请大家帮我。
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ExtDlgs;
type
TPict = Record
PicName: string[255];
Height: integer;
Width: Integer;
end;
type
TForm1 = class(TForm)
Button1: TButton;
Button2: TButton;
OpenPictureDialog1: TOpenPictureDialog;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
aPict: TPict;
PictFile: file of TPict;
implementation
{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
begin
AssignFile(PictFile,Temp.dat);
Rewrite(PictFile);
CloseFile(PictFile);
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
AssignFile(PictFile,Temp.dat);
FileMode := fmOpenReadWrite;
Reset(PictFile);
Seek(PictFile,0);
aPict.PicName := 2222;
aPict.Height := 10;
aPict.Width := 10;
Write(PictFile,aPict);
CloseFile(PictFile);
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
if OpenPictureDialog1.Execute then
begin
end;
end;
end.
AssignFile(PictFile,application.ExeName+Temp.dat);
OpenPictureDialog1执行后改变了程序的相对路径，你改成绝对路径就没问题
OpenPictureDialog1.execute后改变了当前目录路径。
AssignFile(PictFile,Temp.dat)要改成
AssignFile(PictFile,Extractfilepath(Application.exename)+Temp.dat);
1)调用各类标准对话框后，程序的当前路径CurrentDir都被改变为对话框
选中的路径。也就是说，当前路径与应用程序的所在路径不是一个概念.
2)AssignFile的第2个参数---文件名，最好加上相对路径.
我感觉不是上面说的问题，问题是，你的button2的行为可能改变了参数的值，使得文件名改变而找不到要打开的文件造成的，最好在button2click事件中具有容错性，即发生错误时，参数恢复到create时的状态
