TUniCanvas BUG?

[Ken Lewis]

UniGUI 1555

var
  tmpStream : TMemoryStream;
begin
  ......
  TBlobField(FieldByName('li_image')).SaveToStream(tmpStream);
  tmpStream.Position :=0;
  UniCanvas1.Color := clWhite;
  UniCanvas1.Clear;
  uniCanvas1.LoadFromStream(tmpStream);  //When I use this ,the picture is not shown;
  tmpStream.SaveToFile(UniServerModule.StartPath +  'images/1.png');
  UniCanvas1.LoadFromFile(UniServerModule.StartPath +  'images/1.png');  //The picture is shown;
end;

 

[Sherzod]

Hello,

What type of image are you storing in a blob?

[Ken Lewis]

The file type maybe *.jpg, *.png, or other image types.
In this example, I saved .png file in blob.

[likemike]

I don't see any creation of tmpStream...
Try this:
 

var
  tmpStream : TMemoryStream;
begin
  tmpStream:=TMemorystream.Create; 
  TRY
    TBlobField(FieldByName('li_image')).SaveToStream(tmpStream);
    tmpStream.Position :=0;
    UniCanvas1.Color := clWhite;
    UniCanvas1.Clear;
    uniCanvas1.LoadFromStream(tmpStream);  
  FINALLY
    FreeAndNil(tmpStream);
  END;
end;

 

[Ken Lewis]

I only pasted the main part of the code, the part of the code you mentioned is actually there.

Design page:

Run page:  When I click btn1:

 

And when I click btn2:


Source Code:

procedure TSysParamFrm.btn1Click(Sender: TObject);
var
  tmpStream : TMemoryStream;
begin
  tmpStream:=TMemorystream.Create;
  try
    with qryGetImage do
    begin
      Close;
      Open;
      if not IsEmpty then
      begin
        TBlobField(FieldByName('li_image')).SaveToStream(tmpStream);
        tmpStream.Position :=0;
        UniCanvas1.Color := clWhite;
        UniCanvas1.Clear;
        uniCanvas1.LoadFromStream(tmpStream);
      end;
      Close;
    end;
  finally
    FreeAndNil(tmpStream);
  end;
end;

procedure TSysParamFrm.btn2Click(Sender: TObject);
var
  tmpStream : TMemoryStream;
begin
  tmpStream:=TMemorystream.Create;
  try
    with qryGetImage do
    begin
      Close;
      Open;
      if not IsEmpty then
      begin
        TBlobField(FieldByName('li_image')).SaveToStream(tmpStream);
        tmpStream.Position :=0;
        UniCanvas1.Color := clWhite;
        UniCanvas1.Clear;
        tmpStream.SaveToFile(UniServerModule.StartPath +  'images/1.png');
        UniCanvas1.LoadFromFile(UniServerModule.StartPath +  'images/1.png');
      end;
      Close;
    end;
  finally
    FreeAndNil(tmpStream);
  end;
end;

 

[Sherzod]

Hello,

Sorry, are you using trial version?