Printing control and setting its position on A4 page - wpf

Question

I am trying to print selected control to PDF/printer yet I have problem with positioning it on printed page.
When I changed location in Rect it doesn't affect the outcome. I want the control to be in the center of the page or at least the left top corner of the control should be in left top corner of the page, but all the time I have the same picture which starts at the middle of page.
This is my code:
private async Task PrintObjectVisual(bool canUserSelectPrinter, FrameworkElement frameworkElement)
{
if (_CreatePrinterDialog(canUserSelectPrinter, out var prnt)) return;
var offset = VisualTreeHelper.GetOffset(frameworkElement);
Transform originalScale = frameworkElement.LayoutTransform.Clone();
try
{
bool allowForceLandscape = true;
bool forceLandscape =
allowForceLandscape &&
(_starMainPage.ActPage.PresPage.PrintLandscape || frameworkElement.ActualWidth > prnt.PrintableAreaWidth)
||
(frameworkElement is IGraphViewControl || frameworkElement is IMapViewControl);
double scale = 0.0;
PageMediaSize pageSize = null;
pageSize = new PageMediaSize(PageMediaSizeName.ISOA4, CmToPx(29.7), CmToPx(21));
prnt.PrintTicket.PageMediaSize = pageSize;
if (forceLandscape)
{
prnt.PrintTicket.PageOrientation = PageOrientation.Landscape;
if (pageSize.Width != null && pageSize.Height != null)
scale = Math.Min(
(pageSize.Height.Value / frameworkElement.ActualWidth), (pageSize.Width.Value / frameworkElement.ActualHeight));
}
else
{
prnt.PrintTicket.PageOrientation = PageOrientation.Portrait;
if (pageSize.Width != null && pageSize.Height != null)
scale = Math.Min(
(pageSize.Width.Value / frameworkElement.ActualWidth), (pageSize.Height.Value / frameworkElement.ActualHeight));
}
//if (scale > 1.0)
// scale = 1.0;
frameworkElement.LayoutTransform = new ScaleTransform(scale, scale);
// after a thought i know that i might not need it
//var size = _GetPrintAreaSize(forceLandscape, pageSize);
//frameworkElement.Measure(size);
//frameworkElement.Arrange(
// new Rect(new Point(0, 0), size));
prnt.PrintVisual(frameworkElement, $"Printing Object {frameworkElement.Name}");
}
catch (Exception e)
{
PresHelper.WriteToDebug(_presBaseObject, e);
}
finally
{
frameworkElement.LayoutTransform = originalScale;
// after a thought i know that i might not need it
//Size size2 = new Size(_starMainPage.Canvas.ActualWidth, _starMainPage.Canvas.ActualHeight);
//frameworkElement.Measure(size2);
//var x = offset.X - (offset.X * 2);// offset.X
//var y = offset.Y - (offset.Y * 2);// offset.X
//frameworkElement.Arrange(new Rect(new Point(x, y), size2));
}
}
private static bool _CreatePrinterDialog(bool canUserSelectPrinter, out PrintDialog prnt)
{
prnt = new PrintDialog();
if (canUserSelectPrinter)
{
var result = prnt.ShowDialog();
if (result == false)
return true;
}
return false;
}
private Size _GetPrintAreaSize(bool forceLandscape, PageMediaSize pageSize)
{
if (pageSize.Height == null || pageSize.Width == null) throw new NullReferenceException($"Page size values are null! Can't print without it.");
Size size;
if (forceLandscape)
size = new Size(pageSize.Height.Value, pageSize.Width.Value);
else
size = new Size(pageSize.Width.Value, pageSize.Height.Value);
return size;
}

Answer 1

Ok, so after some time on it I have solved the problem.
I assign original Canvas.LeftProperty and TopProperty to some private class members and then assign my own (double) values.
This code is just before the printing.
Later i'm assigning old values:
frameworkElement.LayoutTransform = new ScaleTransform(scale, scale);
left = (double)frameworkElement.GetValue(Canvas.LeftProperty);
top = (double)frameworkElement.GetValue(Canvas.TopProperty);
frameworkElement.SetValue(Canvas.LeftProperty, _marginSize);
frameworkElement.SetValue(Canvas.TopProperty, _marginSize);
prnt.PrintVisual(frameworkElement, $"Printing MikObject {frameworkElement.Name}");
}
catch (Exception e)
{
PresHelper.WriteToDebug(_presBaseObject, e);
}
finally
{
frameworkElement.SetValue(Canvas.LeftProperty, left);
frameworkElement.SetValue(Canvas.TopProperty, top);
frameworkElement.LayoutTransform = originalScale;
}