关于用ADOQuery往Access数据库中保存和读取图片的问题。

Question

Access中图片字段类型为“OLE对象”当数据库里已经有记录时，但是图片字段为空，我要补一张图片在某个记录就要用到updat语句，那么怎么用ADOQuery往这个记录里写入图片，并怎么读出？

Answer 1

//给你一个自定义函数:function imagesavetosql(dataset:TCustomADODataSet;zdxh:integer;picname:string):boolean;
var
  imagebmp:Timage;
  imagejpg:Tjpegimage;
  imageico:Ticon;
  zhbl:Tbitmap;
  lx:string;
  image:Timage;
begin
  imagebmp:=Timage.Create(nil);
  imagejpg:=Tjpegimage.Create;
  imageico:=Ticon.Create;
  zhbl:=Tbitmap.Create;
  image:=Timage.Create(nil);
  image.Picture.LoadFromFile(picname);
  image.Hint:=picname;
  image.showhint:=true;
  if image.Hint<>'' then
  begin
     lx:=ExtractFileExt(image.Hint);
     if uppercase(lx)='.BMP' then
     begin
     imagebmp.Picture.Bitmap.LoadFromFile(image.Hint);
     end;
     if uppercase(lx)='.JPG' then
     begin
     imagejpg.LoadFromFile(image.Hint);
     imagebmp.Picture.Bitmap.Assign(imagejpg);
     end;
     if uppercase(lx)='.ICO' then
     begin
     imageico.LoadFromFile(image.Hint);
     zhbl.Width:=imageico.Width;
     zhbl.Height:=imageico.Height;
     zhbl.canvas.Draw(0,0,imageico);
     end;
  end;
  try
  if uppercase(lx)='.ICO' then
  begin
  dataset.Fields[zdxh].Assign(zhbl);
  end
  else
  begin
  dataset.Fields[zdxh].Assign(imagebmp.Picture);
  end;
  result:=true;
  finally
  imagebmp.Free;
  imagejpg.Free;
  imageico.Free;
  zhbl.Free;
  image.Free;
  end;
end;

Answer 2

//更新图片procedure TForm1.Button1Click(Sender: TObject);  
var fp_temp : file of byte;
begin
  openpicturedialog1.Filter:='All (*.Jpg;*.Bmp)|*.jpg;*.bmp';
  openpicturedialog1.FileName:='';
  openpicturedialog1.Title:='选择图片';
  openpicturedialog1.Execute;
  if openpicturedialog1.FileName='' then exit;
  AssignFile(fp_temp,openpicturedialog1.FileName);
  Reset(fp_temp);
  if filesize(fp_temp)>206000 then
    begin
      application.MessageBox('所选择的图片不能大于200K ','系统提示',MB_OK+MB_ICONINFORMATION);
      CloseFile(fp_temp);
      exit;
    end;
  CloseFile(fp_temp);
  adoquery1.edit;
  imagesavetosql(adoquery1,0,openpicturedialog1.FileName);
  adoquery1.Post;
end;

Answer 3

//另存出图片(从数据库中）procedure TForm1.Button2Click(Sender: TObject);
begin
  savedialog1.Filter:='All (*.Jpg;*.Bmp)|*.jpg;*.bmp';
  savedialog1.FileName:='';
  savedialog1.Execute;
  if savedialog1.FileName<>'' then
    DBimage1.Picture.SaveToFile(savedialog1.FileName+'.jpg');
end;

Answer 4

使用dbimageex控件,就像DBEdit一樣的使用

Answer 5

先用ADOQUERY打开你要更新的表，设置为EDIT状态。通过流存取
procedure TForm1.Button1Click(Sender: TObject);//保存
var
  mystream : TMemoryStream;
begin
  mystream := TMemoryStream.Create;
  try
    Image1.Picture.Graphic.SaveToStream(mystream);
    mystream.Position := 0;
    with ADOQuery1 do
    begin
      close;
      open;
      Append;
      TBlobField(fieldbyname('pic')).LoadFromStream(mystream);
      Post;
    end;
  finally
    mystream.Free;
  end;
end;

Answer 6

http://blog.csdn.net/jinzhili/archive/2005/11/04/522994.aspx

Answer 7

http://blog.csdn.net/jinzhili/archive/2005/11/04/522994.aspx
这里的好详细