"Jeff" <jrush@usa.net> wrote in message
news:1176841241.275965.313110@l77g2000hsb.googlegroups.com...
>I have designed a set of classes which all accept a graphics object
> and then render lines, rectanges, text, etc to that object. There is
> a "parent" class which controls the instantiation of each class and
> also calls the render method for each class, passing the form's
> graphic object. This parent class also controls the zooming in/out
> via a matrix. Everything works wonderfully.
>
> I now have a need for an additional class which will accept a PDF file
> and render it onto the same form. I want to build this class just
> like the others, which means giving it a method which accepts a
> Graphics object. I'm using a 3rd party control by Visage as part of
> this new class. This Visage control even has a method called
> "PaintToDC". The documentation for this method is as follows:
>
> "PaintToDC (DC: HDC; em11, em12, em21, em22, dx, dy: Double)
> Render the current page to the device context specifed from DC
> parameter.the additional
> parameters are for specifying the tranformation matrix used for
> rendering.
> By using transformation matrixes you will be able to scale/rotate/skew
> etc the rendered page.
> The default transformation matrix is 1,0,0,1,0,0"
>
> The Problem: This control does not mesh with my current setup. The
> "paint" does not scroll like the other classes. Is this because I'm
> doing a GetHDC and then a ReleaseHDC on the Graphics object as opposed
> to simply passing the Graphics object ByRef? If so, is there
> something I can do within my "parent" class which will force this
> Visage control to behave like my other classes when it comes to
> scrolling and zooming?

"Michael C" <nospam@nospam.com> wrote in message
news:%23sSLbhWgHHA.668@TK2MSFTNGP05.phx.gbl...
> "Jeff" <jrush@usa.net> wrote in message
> news:1176841241.275965.313110@l77g2000hsb.googlegroups.com...
>>I have designed a set of classes which all accept a graphics object
>> and then render lines, rectanges, text, etc to that object. There is
>> a "parent" class which controls the instantiation of each class and
>> also calls the render method for each class, passing the form's
>> graphic object. This parent class also controls the zooming in/out
>> via a matrix. Everything works wonderfully.
>>
>> I now have a need for an additional class which will accept a PDF file
>> and render it onto the same form. I want to build this class just
>> like the others, which means giving it a method which accepts a
>> Graphics object. I'm using a 3rd party control by Visage as part of
>> this new class. This Visage control even has a method called
>> "PaintToDC". The documentation for this method is as follows:
>>
>> "PaintToDC (DC: HDC; em11, em12, em21, em22, dx, dy: Double)
>> Render the current page to the device context specifed from DC
>> parameter.the additional
>> parameters are for specifying the tranformation matrix used for
>> rendering.
>> By using transformation matrixes you will be able to scale/rotate/skew
>> etc the rendered page.
>> The default transformation matrix is 1,0,0,1,0,0"
>>
>> The Problem: This control does not mesh with my current setup. The
>> "paint" does not scroll like the other classes. Is this because I'm
>> doing a GetHDC and then a ReleaseHDC on the Graphics object as opposed
>> to simply passing the Graphics object ByRef? If so, is there
>> something I can do within my "parent" class which will force this
>> Visage control to behave like my other classes when it comes to
>> scrolling and zooming?
>
> AFAIK, you're stuck. It looks like the control does not use GDI+ which is
> what is needed to use matrix transforms. It appears the control is using
> plain old GDI which simply does not support this feature. You could paint
> to a bitmap and then paint that bitmap to the form but the result will be
> poor. The only solution I can think of is to find a control that does
> support GDI+ but I don't think that's going to be easy.
>
> BTW, you should pass objects around ByVal generally.
>
> Michael
>