Drawing Measurements / PageUnits

gregsohl

I'm having some difficulty getting the drawing coordinates measured correctly when attempting to draw to the PDFControl.Canvas. The PageUnits show they are set to GraphicsUnits.Display which is documented as 1/75th of an inch. I've attempted to adjust my coordinates based on this without success. I've also changes the PageUnits to GraphicsUnits.Inch and had similar results - everything is off by about 20%.

Is there some additional piece of information I need to know to get this correct? Here is a sample of code where I'm simply drawing an X from corner to corner of an 8.5x11 page (note the printer page bounds are always delivered in 1/100 of an inch:

private void OnPrintPDFPage(object sender, PrintPageEventArgs e)
{
pdfControl1.DrawMetafile(tern1.TerPageMetafile(m_iPrint_Page),300,300); // TerPageMetafile creates pages in 1/300 inches resolution

// Draw a big X on the page
Graphics gr = pdfControl1.Canvas;

float left, right, top, bottom;

left = ((float)e.PageBounds.Left) * (float)0.75;
right = ((float)e.PageBounds.Right) * (float)0.75;
top = ((float) e.PageBounds.Top) * (float)0.75;
bottom = ((float) e.PageBounds.Bottom) * (float)0.75;

gr.DrawLine(new Pen(new SolidBrush(Color.Black), (float)0), new PointF(left, top), new PointF(right, bottom));
gr.DrawLine(new Pen(new SolidBrush(Color.Black), (float)0), new PointF(right, top), new PointF(left, bottom));

The right and bottom always come out beyond the 8.5x11 edges. Any help is appreciated while I still have some hair left.

Thanks.

support

Hi,

I suggest to work with integer coordinates since this is what the PDF engine internally also does:

Code

procedure TWinForm.PDFControl1_BeforeEndPage(Sender: System.Object);
var x, y : Integer;
begin
   x := Round( 8.5 * pdfControl1.Canvas.DpiX );
   y := Round( 11 * pdfControl1.Canvas.DpiX );
   pdfControl1.Canvas.DrawString('Hello World',
   System.Drawing.Font.Create('Comic Sans MS', 24),
   System.Drawing.SolidBrush.Create(Color.Black),40, 50);


   pdfControl1.Canvas.DrawLine(
      System.Drawing.SystemPens.WindowText,
      0,0,
      x, y
      );
end;

Alles anzeigen

This code uses the BeforeEndPage event of wPDFControl under .NET. (Language Delphi .NET)