发变一个picture(100分)

//先执行本过程,改变form1.image1.picture,并把原image1.picture保存到form1.fpicture
procedure tform1.bnt1click(sender:tobject);
var
tmpPicture:tPicture;
begin
tmpPicture:=image1.Picture;
image1.Picture:=fPicture; // form1.fPicture:tpicture已建立并保存了一图片
fPicture:=tmpPicture; //保存不了
Update;
end;

//执行此过程,不能得到原form1.image1.picture;
procedure tform1.bnt2click(sender:tobject);
var
tmpPicture:tPicture;
begin
tmpPicture:=image1.Picture;
image1.Picture:=fPicture;
fPicture:=tmpPicture;
Update;
end;

我错在哪?

什么意思？ picture控件？ 干吗？

用TBitmap试一下。

把 := 改为 Assign
procedure tform1.bnt1click(sender:tobject);
var
tmpPicture:tPicture;
begin
tmpPicture.Assign (image1.Picture);
image1.Picture.Assign (fPicture);
fPicture.Assign (tmpPicture); Update;
end;

procedure tform1.bnt2click(sender:tobject);
var
tmpPicture:tPicture;
begin
tmpPicture.Assign (image1.Picture);
image1.Picture.Assign (fPicture);
fPicture.Assign (tmpPicture);
Update;
end;

var
tmpPicture:tPicture;
begin
tmpPicture.Assign (image1.Picture);
image1.Picture.Assign (fPicture);
fPicture.Assign (tmpPicture);
Update;
end;

:= 只是地址直接链接
用.Assign才会复制啦

二個事件都一樣，建議改成這樣,我調試可以成功：
procedure TForm1.BitBtn1Click(Sender: TObject);
var
tmpPicture:tPicture;
begin
tmpPicture:=tPicture.Create; //不要忘記
tmpPicture.Assign(image1.Picture);//此有變化
image1.Picture:=fPicture;
fPicture:=tmpPicture;
Update;
end;

多人接受答案了。