What is the correct way to draw text in different rotation?

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I have developed an application to create, edit and print labels. In this application it is possible to insert rectangles in which there are several lines of text and the user can set the font, the color,.., and the orientation among 0°, 90°, 270° and 180° degrees. So I wrote a method to draw the text inside the bounding rectangle, according to the orientation, using GDI+ and DrawString method.

C#

switch (RotationAngle)
            {
                case 90:
                    g.RotateTransform(90);
                    objRec = DrawRectangle.GetNormalizedRectangle(objRec.Top, 
                          -objRec.Left, objRec.Bottom, -objRec.Right);
                    g.DrawString(lines[i], textFont, brush, objRec, sf);
                    g.RotateTransform(-90);
                    break;
                case 180:
                    g.RotateTransform(180);
                    objRec = DrawRectangle.GetNormalizedRectangle(-objRec.Left, 
                          -objRec.Top, -objRec.Right, -objRec.Bottom); 
                    g.DrawString(lines[i], textFont, brush, objRec, sf);
                    g.RotateTransform(-180);
                    break;
                case 270:
                    g.RotateTransform(270);
                    objRec = DrawRectangle.GetNormalizedRectangle(-objRec.Top, 
                        +objRec.Left, -objRec.Bottom, +objRec.Right);
                    g.DrawString(lines[i], textFont, brush, objRec, sf);
                    g.RotateTransform(-270);
                    break;
                case 0:
                    g.DrawString(lines[i], textFont, brush, objRec, sf);
                    break;
            }

where "objRect" is the original rectangle set by the user. The method works for all the orientation, but not for 180°! In this case the text is drawn as at 0 degrees. I really don't know what to do and I'm going crazy in finding the correct way to solve the problem. What is the correct way to draw text in different rotation? Any help would be pleasant. Thanks in advance.

Posted 21-Oct-13 3:55am

Sara Noemi

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Sergey Alexandrovich Kryukov 21-Oct-13 10:55am

Weird. You are using the best method, only the code is no good. You should not use the case, use the RotationAngle and -RotationAngle instead. 1) Rewrite the code, 2) use "Improve question" and change it in the question, 3) for experiment, try not 180, but, say 181, 4) run it all under the debugger.

Did you try to create new Matrix variable and assign Transform property to it, instead of rotating back and forth?

Don't even play with the idea of leaving the code as is. Refactor it properly first, and then, it you do, we can discuss the problem if it is still there...

—SA

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OriginalGriff · Accepted Answer · 2013-10-21T06:00:00

A quick check with your code in the paint event of a panel gives we the 180 working fine - but I can't use your DrawRectangle.GetNormalizedRectangle method because I don't have it, so I used TranslateTransform instead:

C#

g.TranslateTransform(myDrawingPanel.Width, myDrawingPanel.Height);
g.RotateTransform(180);
//objRec = DrawRectangle.GetNormalizedRectangle(-objRec.Left,
//      -objRec.Top, -objRec.Right, -objRec.Bottom);
g.DrawRectangle(Pens.Red, objRect);
g.DrawString(lines[i], textFont, brush, objRec, sf);
g.RotateTransform(-180);

That worked fine - the text was upside down and right to left, as I would expect.
I would suggest that you want to look at your method - it may be that it is causing the problem. It could also be worth looking at your StringFormat settings - again I don't have those.

"The graphics used in this method is the Graphics object of a PrintPageEventArgs; it seems that this method doesn't work for 180° just if I select a pdf virtual printer. In all other cases it works fine and produce the result expected. Only for pdf printers and orientation 180° degrees, the instruction g.RotateTransform(-180) seems to be ignored at all! I know that it seems weird, but I can't find a solution!"

I just tried it with mine:

C#

    PrintDocument pd = new PrintDocument();
    pd.PrintPage += new PrintPageEventHandler(pd_PrintPage);
    pd.Print();
    }

void pd_PrintPage(object sender, PrintPageEventArgs e)
    {
    Graphics g = e.Graphics;
    RectangleF objRec = new RectangleF(50, 50, 100, 75);
    g.TranslateTransform(myDrawingPanel.Width, myDrawingPanel.Height);
    g.RotateTransform(180);
    g.DrawRectangle(Pens.Red, new Rectangle(50, 50, 100, 75));
    g.DrawString("Hello", font, Brushes.Blue, new RectangleF(50, 50, 100, 75), new StringFormat());
    g.RotateTransform(-180);
    }

Using CutePDF as the printer driver and it worked fine - I get the text in blue, upside down, inside a red box.

Which PDF system are you using?