Graphics.DrawString位于printdocument宽度的中心

Question

I'm attempting to center a string on a printdocument. I've done the following with an image and it works but doesn't seem to work the same with a string.

Here is the code that I used to center the image

e.Graphics.DrawImage(logo, (e.MarginBounds.Width / 2) - (logo.Width / 2), height);

The text i'm trying to center is being supply from a Tab in a TabControl

 using (var sf = new StringFormat())
 {
       height = logo.Height + 15;
       sf.LineAlignment = StringAlignment.Center;
       sf.Alignment = StringAlignment.Center;
       e.Graphics.DrawString(tabData.Text, new Font(this.Font.Name, 10),
            new SolidBrush(tabData.ForeColor),
            (e.MarginBounds.Width / 2) - (txtData.Width / 2), height, sf);
  }

I have also tried below and used string_size.Width /2 in place of txtData.Width

SizeF string_size = e.Graphics.MeasureString(tabData.Text, tabData.Font);

EDIT

Current full code

        float height = 0;
        tabData.Text = "Date Range: 02/02/2010 - 08/09/2013"; //set just for testing
        using (var logo = Properties.Resources.title)
        {
            e.Graphics.DrawImage(logo, e.PageBounds.Left + (e.MarginBounds.Width / 2) - (logo.Width / 2), height);
            height = logo.Height + 15;
        }

        using (var sf = new StringFormat())
        {

            sf.LineAlignment = StringAlignment.Center;
            sf.Alignment = StringAlignment.Center;
            e.Graphics.DrawString(tabData.Text, new Font(this.Font.Name, 10), new SolidBrush(tabData.ForeColor), e.PageBounds.Left + (e.PageBounds.Width / 2), height, sf);
        }

Don't understand why I have to use a mixture of PageBounds and MarginBounds to center the Image then with the text it will center with either both MarginBounds or both PageBounds

Answer 1

The following works for me. You may need to use PageBounds if your margins are not uniform.

    void pd_PrintPage(object sender, PrintPageEventArgs e)
    {
        int w = e.MarginBounds.Width / 2;
        int x = e.MarginBounds.Left;
        int y = e.MarginBounds.Top;
        Font printFont = new Font("Arial", 10);
        Bitmap logo = System.Drawing.SystemIcons.WinLogo.ToBitmap();

        int height = 100 + y;
        string tabDataText = "Hello World";
        var tabDataForeColor = Color.Blue;
        var txtDataWidth = e.Graphics.MeasureString(tabDataText, printFont).Width;

        e.Graphics.DrawImage(logo,
            e.MarginBounds.Left + (e.MarginBounds.Width / 2) - (logo.Width / 2),
            e.MarginBounds.Top + (e.MarginBounds.Height / 2) - (logo.Height));

        using (var sf = new StringFormat())
        {
            height += logo.Height + 15;
            sf.LineAlignment = StringAlignment.Center;
            sf.Alignment = StringAlignment.Center;
            e.Graphics.DrawString(tabDataText, new Font(this.Font.Name, 10),
                 new SolidBrush(tabDataForeColor),
                 e.MarginBounds.Left + (e.MarginBounds.Width / 2),
                 e.MarginBounds.Top + (e.MarginBounds.Height / 2) + (logo.Height / 2) + 15,
                 sf);
        }

        e.HasMorePages = false;
    }

Edit Response

Output using your new code. Are you saying this is what you want?

Or are you wanting this?

The margin is a rectangle that sits inside the page. It is possible that those margins are asymmetrical so if you want the absolute center you should reference PageBounds .

Additionally, your text is center aligned so that makes the reference point of drawing the text in the middle of the String instead of top left like the logo .