数据库填加JPG文件

Question

以下是前提条件
    定义类型：griphic类
BEGINEND

Answer 1

var
pic:TJpegImage;
bmp:TBitmap;
sm:TStringStream;
begin
    if develop_query.State=dsInactive then
    begin
        MessageDlg('没有记录，请查询！',mtError,[mbOK],0);
        exit;
    end;
    OpenDialog1.Title:='打开照片';
    if not OpenDialog1.Execute then
        exit;
    if OpenDialog1.FileName=NULL then
        exit;
    try
        pic:=TJpegImage.Create;
        bmp:=TBitmap.Create;
        sm:=TStringstream.Create('');        pic.LoadFromFile(OpenDialog1.Filename);
        bmp.Assign(pic);
        bmp.SaveToStream(sm);        if not (develop_query.State in [dsInsert,dsEdit]) then
        begin
            develop_query.edit;
            TBlobField(develop_query.FieldByName('zp')).LoadFromStream(sm);            develop_query.Post;
        end
        else
        begin
            TBlobField(develop_query.FieldByName('zp')).LoadFromStream(sm);
        end;
    finally
        bmp.Free;
        pic.free;
        sm.free;
    end;
end;

Answer 2

uses jpeg;
...var v_1:TJPEGImage;
begin
  v_1:=TJPEGImage.Create;
  v_1.LoadFromFile('c:\aa.jpg');
  table1.fieldbyname('photo').assigned(v_1);
end;

Answer 3

procedure TForm1.Button1Click(Sender: TObject); 
Var
　jpeg: TJPEGImage; 
　bmp: TBitmap; 
Begin 
　bmp:= TBitmap.Create; 
　try 
　　bmp.LoadFromFile('e:\car.bmp'); 
　　jpeg:= TJPEGImage.Create; 
　　try
　　　jpeg.Assign(bmp); 
　　　jpeg.compress; 
　　　jpeg.SaveTofile('e:\car.jpg'); 
　　finally
　　　jpeg.free
　　end; 
　finally
　　bmp.free
　end; 
end; 　　将上面代码中的 jpeg 和 bmp 交换一下就成了将 jpeg 转换为 bmp 。